Support Direct Boot mode

25 files changed, 854 insertions, 30 deletions

diff --git a/COPYING b/COPYING
new file mode 100644
index 000000000..f288702d2
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
+
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
+  0. Definitions.
+
+  "This License" refers to version 3 of the GNU General Public License.
+
+  "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+  "The Program" refers to any copyrightable work licensed under this
+License.  Each licensee is addressed as "you".  "Licensees" and
+"recipients" may be individuals or organizations.
+
+  To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy.  The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+
+  A "covered work" means either the unmodified Program or a work based
+on the Program.
+
+  To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy.  Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+
+  To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies.  Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+
+  An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License.  If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+
+  1. Source Code.
+
+  The "source code" for a work means the preferred form of the work
+for making modifications to it.  "Object code" means any non-source
+form of a work.
+
+  A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+
+  The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major Component, or to implement a Standard Interface for which an
+implementation is available to the public in source code form.  A
+"Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work runs, or a compiler used to
+produce the work, or an object code interpreter used to run it.
+
+  The "Corresponding Source" for a work in object code form means all
+the source code needed to generate, install, and (for an executable
+work) run the object code and to modify the work, including scripts to
+control those activities.  However, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work.  For example, Corresponding Source
+includes interface definition files associated with source files for
+the work, and the source code for shared libraries and dynamically
+linked subprograms that the work is specifically designed to require,
+such as by intimate data communication or control flow between those
+subprograms and other parts of the work.
+
+  The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the Corresponding
+Source.
+
+  The Corresponding Source for a work in source code form is that
+same work.
+
+  2. Basic Permissions.
+
+  All rights granted under this License are granted for the term of
+copyright on the Program, and are irrevocable provided the stated
+conditions are met.  This License explicitly affirms your unlimited
+permission to run the unmodified Program.  The output from running a
+covered work is covered by this License only if the output, given its
+content, constitutes a covered work.  This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+
+  You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force.  You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
+the terms of this License in conveying all material for which you do
+not control copyright.  Those thus making or running the covered works
+for you must do so exclusively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+
+  Conveying under any other circumstances is permitted solely under
+the conditions stated below.  Sublicensing is not allowed; section 10
+makes it unnecessary.
+
+  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
+
+  No covered work shall be deemed part of an effective technological
+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
+
+  When you convey a covered work, you waive any legal power to forbid
+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
+the covered work, and you disclaim any intention to limit operation or
+modification of the work as a means of enforcing, against the work's
+users, your or third parties' legal rights to forbid circumvention of
+technological measures.
+
+  4. Conveying Verbatim Copies.
+
+  You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms added in accord with section 7 apply to the code;
+keep intact all notices of the absence of any warranty; and give all
+recipients a copy of this License along with the Program.
+
+  You may charge any price or no price for each copy that you convey,
+and you may offer support or warranty protection for a fee.
+
+  5. Conveying Modified Source Versions.
+
+  You may convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+
+    a) The work must carry prominent notices stating that you modified
+    it, and giving a relevant date.
+
+    b) The work must carry prominent notices stating that it is
+    released under this License and any conditions added under section
+    7.  This requirement modifies the requirement in section 4 to
+    "keep intact all notices".
+
+    c) You must license the entire work, as a whole, under this
+    License to anyone who comes into possession of a copy.  This
+    License will therefore apply, along with any applicable section 7
+    additional terms, to the whole of the work, and all its parts,
+    regardless of how they are packaged.  This License gives no
+    permission to license the work in any other way, but it does not
+    invalidate such permission if you have separately received it.
+
+    d) If the work has interactive user interfaces, each must display
+    Appropriate Legal Notices; however, if the Program has interactive
+    interfaces that do not display Appropriate Legal Notices, your
+    work need not make them do so.
+
+  A compilation of a covered work with other separate and independent
+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
+in or on a volume of a storage or distribution medium, is called an
+"aggregate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit.  Inclusion of a covered work
+in an aggregate does not cause this License to apply to the other
+parts of the aggregate.
+
+  6. Conveying Non-Source Forms.
+
+  You may convey a covered work in object code form under the terms
+of sections 4 and 5, provided that you also convey the
+machine-readable Corresponding Source under the terms of this License,
+in one of these ways:
+
+    a) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by the
+    Corresponding Source fixed on a durable physical medium
+    customarily used for software interchange.
+
+    b) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by a
+    written offer, valid for at least three years and valid for as
+    long as you offer spare parts or customer support for that product
+    model, to give anyone who possesses the object code either (1) a
+    copy of the Corresponding Source for all the software in the
+    product that is covered by this License, on a durable physical
+    medium customarily used for software interchange, for a price no
+    more than your reasonable cost of physically performing this
+    conveying of source, or (2) access to copy the
+    Corresponding Source from a network server at no charge.
+
+    c) Convey individual copies of the object code with a copy of the
+    written offer to provide the Corresponding Source.  This
+    alternative is allowed only occasionally and noncommercially, and
+    only if you received the object code with such an offer, in accord
+    with subsection 6b.
+
+    d) Convey the object code by offering access from a designated
+    place (gratis or for a charge), and offer equivalent access to the
+    Corresponding Source in the same way through the same place at no
+    further charge.  You need not require recipients to copy the
+    Corresponding Source along with the object code.  If the place to
+    copy the object code is a network server, the Corresponding Source
+    may be on a different server (operated by you or a third party)
+    that supports equivalent copying facilities, provided you maintain
+    clear directions next to the object code saying where to find the
+    Corresponding Source.  Regardless of what server hosts the
+    Corresponding Source, you remain obligated to ensure that it is
+    available for as long as needed to satisfy these requirements.
+
+    e) Convey the object code using peer-to-peer transmission, provided
+    you inform other peers where the object code and Corresponding
+    Source of the work are being offered to the general public at no
+    charge under subsection 6d.
+
+  A separable portion of the object code, whose source code is excluded
+from the Corresponding Source as a System Library, need not be
+included in conveying the object code work.
+
+  A "User Product" is either (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling.  In determining whether a product is a consumer product,
+doubtful cases shall be resolved in favor of coverage.  For a particular
+product received by a particular user, "normally used" refers to a
+typical or common use of that class of product, regardless of the status
+of the particular user or of the way in which the particular user
+actually uses, or expects or is expected to use, the product.  A product
+is a consumer product regardless of whether the product has substantial
+commercial, industrial or non-consumer uses, unless such uses represent
+the only significant mode of use of the product.
+
+  "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to install
+and execute modified versions of a covered work in that User Product from
+a modified version of its Corresponding Source.  The information must
+suffice to ensure that the continued functioning of the modified object
+code is in no case prevented or interfered with solely because
+modification has been made.
+
+  If you convey an object code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transferred to the recipient in perpetuity or for a
+fixed term (regardless of how the transaction is characterized), the
+Corresponding Source conveyed under this section must be accompanied
+by the Installation Information.  But this requirement does not apply
+if neither you nor any third party retains the ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+
+  The requirement to provide Installation Information does not include a
+requirement to continue to provide support service, warranty, or updates
+for a work that has been modified or installed by the recipient, or for
+the User Product in which it has been modified or installed.  Access to a
+network may be denied when the modification itself materially and
+adversely affects the operation of the network or violates the rules and
+protocols for communication across the network.
+
+  Corresponding Source conveyed, and Installation Information provided,
+in accord with this section must be in a format that is publicly
+documented (and with an implementation available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+
+  7. Additional Terms.
+
+  "Additional permissions" are terms that supplement the terms of this
+License by making exceptions from one or more of its conditions.
+Additional permissions that are applicable to the entire Program shall
+be treated as though they were included in this License, to the extent
+that they are valid under applicable law.  If additional permissions
+apply only to part of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+
+  When you convey a copy of a covered work, you may at your option
+remove any additional permissions from that copy, or from any part of
+it.  (Additional permissions may be written to require their own
+removal in certain cases when you modify the work.)  You may place
+additional permissions on material, added by you to a covered work,
+for which you have or can give appropriate copyright permission.
+
+  Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright holders of
+that material) supplement the terms of this License with terms:
+
+    a) Disclaiming warranty or limiting liability differently from the
+    terms of sections 15 and 16 of this License; or
+
+    b) Requiring preservation of specified reasonable legal notices or
+    author attributions in that material or in the Appropriate Legal
+    Notices displayed by works containing it; or
+
+    c) Prohibiting misrepresentation of the origin of that material, or
+    requiring that modified versions of such material be marked in
+    reasonable ways as different from the original version; or
+
+    d) Limiting the use for publicity purposes of names of licensors or
+    authors of the material; or
+
+    e) Declining to grant rights under trademark law for use of some
+    trade names, trademarks, or service marks; or
+
+    f) Requiring indemnification of licensors and authors of that
+    material by anyone who conveys the material (or modified versions of
+    it) with contractual assumptions of liability to the recipient, for
+    any liability that these contractual assumptions directly impose on
+    those licensors and authors.
+
+  All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10.  If the Program as you
+received it, or any part of it, contains a notice stating that it is
+governed by this License along with a term that is a further
+restriction, you may remove that term.  If a license document contains
+a further restriction but permits relicensing or conveying under this
+License, you may add to a covered work material governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+
+  If you add terms to a covered work in accord with this section, you
+must place, in the relevant source files, a statement of the
+additional terms that apply to those files, or a notice indicating
+where to find the applicable terms.
+
+  Additional terms, permissive or non-permissive, may be stated in the
+form of a separately written license, or stated as exceptions;
+the above requirements apply either way.
+
+  8. Termination.
+
+  You may not propagate or modify a covered work except as expressly
+provided under this License.  Any attempt otherwise to propagate or
+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+
+  However, if you cease all violation of this License, then your
+license from a particular copyright holder is reinstated (a)
+provisionally, unless and until the copyright holder explicitly and
+finally terminates your license, and (b) permanently, if the copyright
+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
+
+  Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
+  Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License.  If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+  9. Acceptance Not Required for Having Copies.
+
+  You are not required to accept this License in order to receive or
+run a copy of the Program.  Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance.  However,
+nothing other than this License grants you permission to propagate or
+modify any covered work.  These actions infringe copyright if you do
+not accept this License.  Therefore, by modifying or propagating a
+covered work, you indicate your acceptance of this License to do so.
+
+  10. Automatic Licensing of Downstream Recipients.
+
+  Each time you convey a covered work, the recipient automatically
+receives a license from the original licensors, to run, modify and
+propagate that work, subject to this License.  You are not responsible
+for enforcing compliance by third parties with this License.
+
+  An "entity transaction" is a transaction transferring control of an
+organization, or substantially all assets of one, or subdividing an
+organization, or merging organizations.  If propagation of a covered
+work results from an entity transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a right to possession of the
+Corresponding Source of the work from the predecessor in interest, if
+the predecessor has it or can get it with reasonable efforts.
+
+  You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License.  For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+
+  11. Patents.
+
+  A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based.  The
+work thus licensed is called the contributor's "contributor version".
+
+  A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version.  For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+
+  Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+
+  In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement).  To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+
+  If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients.  "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+
+  If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.
diff --git a/LICENSE b/LICENSE
new file mode 120000
index 000000000..d24842f3c
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1 @@
+COPYING
\ No newline at end of file
diff --git a/NOTICE b/NOTICE
index aa325547e..7858ac424 100644
--- a/NOTICE
+++ b/NOTICE
@@ -1,3 +1,15 @@
+Kelar Keyboard is a derivative of the AOSP LatinIME keyboard, licensed
+under the Apache License, Version 2.0, with the notice appearing later
+in this file.
+
+Kelar Keyboard is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.  A copy of the GNU General Public
+License is available in the COPYING file.
+
+Original NOTICE from the AOSP LatinIME project:
+
 
    Copyright (c) 2008, The Android Open Source Project
 
diff --git a/README b/README
new file mode 100644
index 000000000..9a81303b6
--- /dev/null
+++ b/README
@@ -0,0 +1,32 @@
+Kelar Keyboard
+==============
+
+Kelar Keyboard is an input method for Android-based devices aiming to
+provide enhancements over the long-neglected [AOSP LatinIME] keyboard
+on which it was based, while respecting your freedom and privacy.
+
+License
+-------
+
+Kelar Keyboard is [free software]: you can redistribute it and/or
+modify it under the terms of the GNU General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+Kelar Keyboard is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+A copy of the GNU General Public License is available in the
+[COPYING](COPYING) file at the project root near this README.
+
+Note: Kelar Keyboard is a derivative/fork of AOSP LatinIME, which is
+Copyright (c) 2014 The Android Open Source Project, and released
+under the Apache License, Version 2.0.  Except where otherwise noted,
+Kelar Keyboard's changes and additions beyond AOSP LatinIME are
+released under the GNU GPLv3+ license, per the above notice.
+
+
+[AOSP LatinIME]: https://android.googlesource.com/platform/packages/inputmethods/LatinIME/
+[free software]: https://www.gnu.org/philosophy/free-sw.html
diff --git a/README.md b/README.md
new file mode 120000
index 000000000..100b93820
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+README
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index 8fc357bb9..2805ff016 100644
--- a/build.gradle
+++ b/build.gradle
@@ -43,6 +43,10 @@ android {
         }
     }
 
+    buildFeatures {
+        buildConfig = true
+    }
+
     buildTypes {
         debug {
             minifyEnabled false
diff --git a/java/AndroidManifest.xml b/java/AndroidManifest.xml
index 7dce7499a..82ed550eb 100644
--- a/java/AndroidManifest.xml
+++ b/java/AndroidManifest.xml
@@ -60,14 +60,13 @@
     <application android:label="@string/english_ime_name"
          android:icon="@mipmap/ic_launcher"
          android:supportsRtl="true"
-         android:allowBackup="true"
-         android:defaultToDeviceProtectedStorage="true"
-         android:directBootAware="true">
+         android:allowBackup="true">
 
         <!-- Services -->
         <service android:name="LatinIME"
              android:label="@string/english_ime_name"
              android:permission="android.permission.BIND_INPUT_METHOD"
+             android:directBootAware="true"
              android:exported="true"
              android:visibleToInstantApps="true">
             <intent-filter>
diff --git a/java/NOTICE b/java/NOTICE
index aa325547e..7858ac424 100644
--- a/java/NOTICE
+++ b/java/NOTICE
@@ -1,3 +1,15 @@
+Kelar Keyboard is a derivative of the AOSP LatinIME keyboard, licensed
+under the Apache License, Version 2.0, with the notice appearing later
+in this file.
+
+Kelar Keyboard is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.  A copy of the GNU General Public
+License is available in the COPYING file.
+
+Original NOTICE from the AOSP LatinIME project:
+
 
    Copyright (c) 2008, The Android Open Source Project
 
diff --git a/java/src/org/kelar/inputmethod/dictionarypack/CommonPreferences.java b/java/src/org/kelar/inputmethod/dictionarypack/CommonPreferences.java
index e4676b186..a82a8f07b 100644
--- a/java/src/org/kelar/inputmethod/dictionarypack/CommonPreferences.java
+++ b/java/src/org/kelar/inputmethod/dictionarypack/CommonPreferences.java
@@ -19,11 +19,13 @@ package org.kelar.inputmethod.dictionarypack;
 import android.content.Context;
 import android.content.SharedPreferences;
 
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
+
 public final class CommonPreferences {
     private static final String COMMON_PREFERENCES_NAME = "LatinImeDictPrefs";
 
     public static SharedPreferences getCommonPreferences(final Context context) {
-        return context.getSharedPreferences(COMMON_PREFERENCES_NAME, 0);
+        return PreferenceUtils.getSharedPreferences(context, COMMON_PREFERENCES_NAME);
     }
 
     public static void enable(final SharedPreferences pref, final String id) {
diff --git a/java/src/org/kelar/inputmethod/keyboard/KeyboardTheme.java b/java/src/org/kelar/inputmethod/keyboard/KeyboardTheme.java
index e3a14fc25..2c75fbe01 100644
--- a/java/src/org/kelar/inputmethod/keyboard/KeyboardTheme.java
+++ b/java/src/org/kelar/inputmethod/keyboard/KeyboardTheme.java
@@ -20,11 +20,11 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Build.VERSION_CODES;
-import android.preference.PreferenceManager;
 import android.util.Log;
 
 import org.kelar.inputmethod.compat.BuildCompatUtils;
 import org.kelar.inputmethod.latin.R;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -167,7 +167,7 @@ public final class KeyboardTheme implements Comparable<KeyboardTheme> {
     }
 
     public static KeyboardTheme getKeyboardTheme(final Context context) {
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(context);
         final KeyboardTheme[] availableThemeArray = getAvailableThemeArray(context);
         return getKeyboardTheme(prefs, BuildCompatUtils.EFFECTIVE_SDK_INT, availableThemeArray);
     }
diff --git a/java/src/org/kelar/inputmethod/keyboard/MainKeyboardView.java b/java/src/org/kelar/inputmethod/keyboard/MainKeyboardView.java
index 48878e3ea..65542aefd 100644
--- a/java/src/org/kelar/inputmethod/keyboard/MainKeyboardView.java
+++ b/java/src/org/kelar/inputmethod/keyboard/MainKeyboardView.java
@@ -27,7 +27,6 @@ import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Paint.Align;
 import android.graphics.Typeface;
-import android.preference.PreferenceManager;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -57,6 +56,7 @@ import org.kelar.inputmethod.latin.common.Constants;
 import org.kelar.inputmethod.latin.common.CoordinateUtils;
 import org.kelar.inputmethod.latin.settings.DebugSettings;
 import org.kelar.inputmethod.latin.utils.LanguageOnSpacebarUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.TypefaceUtils;
 
 import java.util.WeakHashMap;
@@ -197,7 +197,7 @@ public final class MainKeyboardView extends KeyboardView implements DrawingProxy
 
         PointerTracker.init(mainKeyboardViewAttr, mTimerHandler, this /* DrawingProxy */);
 
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(context);
         final boolean forceNonDistinctMultitouch = prefs.getBoolean(
                 DebugSettings.PREF_FORCE_NON_DISTINCT_MULTITOUCH, false);
         final boolean hasDistinctMultitouch = context.getPackageManager()
diff --git a/java/src/org/kelar/inputmethod/keyboard/emoji/EmojiPalettesView.java b/java/src/org/kelar/inputmethod/keyboard/emoji/EmojiPalettesView.java
index 08c6b4c18..3ac31fb07 100644
--- a/java/src/org/kelar/inputmethod/keyboard/emoji/EmojiPalettesView.java
+++ b/java/src/org/kelar/inputmethod/keyboard/emoji/EmojiPalettesView.java
@@ -22,7 +22,6 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.graphics.Color;
-import android.preference.PreferenceManager;
 import androidx.viewpager.widget.ViewPager;
 import android.util.AttributeSet;
 import android.util.Pair;
@@ -49,6 +48,7 @@ import org.kelar.inputmethod.latin.AudioAndHapticFeedbackManager;
 import org.kelar.inputmethod.latin.R;
 import org.kelar.inputmethod.latin.RichInputMethodSubtype;
 import org.kelar.inputmethod.latin.common.Constants;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.ResourceUtils;
 
 /**
@@ -116,7 +116,7 @@ public final class EmojiPalettesView extends LinearLayout implements OnTabChange
         final KeyboardLayoutSet layoutSet = builder.build();
         final TypedArray emojiPalettesViewAttr = context.obtainStyledAttributes(attrs,
                 R.styleable.EmojiPalettesView, defStyle, R.style.EmojiPalettesView);
-        mEmojiCategory = new EmojiCategory(PreferenceManager.getDefaultSharedPreferences(context),
+        mEmojiCategory = new EmojiCategory(PreferenceUtils.getDefaultSharedPreferences(context),
                 res, layoutSet, emojiPalettesViewAttr);
         mCategoryIndicatorEnabled = emojiPalettesViewAttr.getBoolean(
                 R.styleable.EmojiPalettesView_categoryIndicatorEnabled, false);
diff --git a/java/src/org/kelar/inputmethod/latin/BackupAgent.java b/java/src/org/kelar/inputmethod/latin/BackupAgent.java
index 267014683..a1442a663 100644
--- a/java/src/org/kelar/inputmethod/latin/BackupAgent.java
+++ b/java/src/org/kelar/inputmethod/latin/BackupAgent.java
@@ -23,6 +23,7 @@ import android.content.SharedPreferences;
 import android.os.ParcelFileDescriptor;
 
 import org.kelar.inputmethod.latin.settings.LocalSettingsConstants;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 
 import java.io.IOException;
 
@@ -46,8 +47,7 @@ public final class BackupAgent extends BackupAgentHelper {
         super.onRestore(data, appVersionCode, newState);
 
         // Remove the preferences that we don't want restored.
-        final SharedPreferences.Editor prefEditor = getSharedPreferences(
-                getPackageName() + PREF_SUFFIX, MODE_PRIVATE).edit();
+        final SharedPreferences.Editor prefEditor = PreferenceUtils.getDefaultSharedPreferences(this).edit();
         for (final String key : LocalSettingsConstants.PREFS_TO_SKIP_RESTORING) {
             prefEditor.remove(key);
         }
diff --git a/java/src/org/kelar/inputmethod/latin/BinaryDictionaryGetter.java b/java/src/org/kelar/inputmethod/latin/BinaryDictionaryGetter.java
index 75d2d5d4e..71aa1950f 100644
--- a/java/src/org/kelar/inputmethod/latin/BinaryDictionaryGetter.java
+++ b/java/src/org/kelar/inputmethod/latin/BinaryDictionaryGetter.java
@@ -27,6 +27,7 @@ import org.kelar.inputmethod.latin.makedict.DictionaryHeader;
 import org.kelar.inputmethod.latin.makedict.UnsupportedFormatException;
 import org.kelar.inputmethod.latin.utils.BinaryDictionaryUtils;
 import org.kelar.inputmethod.latin.utils.DictionaryInfoUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 
 import java.io.File;
 import java.io.IOException;
@@ -117,7 +118,7 @@ final public class BinaryDictionaryGetter {
         final SharedPreferences mDictPreferences;
         public DictPackSettings(final Context context) {
             mDictPreferences = null == context ? null
-                    : context.getSharedPreferences(COMMON_PREFERENCES_NAME,
+                    : PreferenceUtils.getSharedPreferences(context, COMMON_PREFERENCES_NAME,
                             Context.MODE_MULTI_PROCESS);
         }
         public boolean isWordListActive(final String dictId) {
diff --git a/java/src/org/kelar/inputmethod/latin/LatinIME.java b/java/src/org/kelar/inputmethod/latin/LatinIME.java
index 5529c2bf5..8022bc7e0 100644
--- a/java/src/org/kelar/inputmethod/latin/LatinIME.java
+++ b/java/src/org/kelar/inputmethod/latin/LatinIME.java
@@ -38,7 +38,6 @@ import android.os.Build;
 import android.os.Debug;
 import android.os.IBinder;
 import android.os.Message;
-import android.preference.PreferenceManager;
 import android.text.InputType;
 import android.util.Log;
 import android.util.PrintWriterPrinter;
@@ -96,6 +95,7 @@ import org.kelar.inputmethod.latin.utils.ImportantNoticeUtils;
 import org.kelar.inputmethod.latin.utils.IntentUtils;
 import org.kelar.inputmethod.latin.utils.JniUtils;
 import org.kelar.inputmethod.latin.utils.LeakGuardHandlerWrapper;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.StatsUtils;
 import org.kelar.inputmethod.latin.utils.StatsUtilsManager;
 import org.kelar.inputmethod.latin.utils.SubtypeLocaleUtils;
@@ -596,7 +596,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     @Override
     public void onCreate() {
         Settings.init(this);
-        DebugFlags.init(PreferenceManager.getDefaultSharedPreferences(this));
+        DebugFlags.init(PreferenceUtils.getDefaultSharedPreferences(this));
         RichInputMethodManager.init(this);
         mRichImm = RichInputMethodManager.getInstance();
         AudioAndHapticFeedbackManager.init(this);
diff --git a/java/src/org/kelar/inputmethod/latin/RichInputMethodManager.java b/java/src/org/kelar/inputmethod/latin/RichInputMethodManager.java
index f364ce982..526c008eb 100644
--- a/java/src/org/kelar/inputmethod/latin/RichInputMethodManager.java
+++ b/java/src/org/kelar/inputmethod/latin/RichInputMethodManager.java
@@ -24,7 +24,6 @@ import android.inputmethodservice.InputMethodService;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.IBinder;
-import android.preference.PreferenceManager;
 import android.util.Log;
 import android.view.inputmethod.InputMethodInfo;
 import android.view.inputmethod.InputMethodManager;
@@ -36,6 +35,7 @@ import org.kelar.inputmethod.compat.InputMethodSubtypeCompatUtils;
 import org.kelar.inputmethod.latin.settings.Settings;
 import org.kelar.inputmethod.latin.utils.AdditionalSubtypeUtils;
 import org.kelar.inputmethod.latin.utils.LanguageOnSpacebarUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.SubtypeLocaleUtils;
 
 import java.util.Collections;
@@ -111,7 +111,7 @@ public class RichInputMethodManager {
     }
 
     public InputMethodSubtype[] getAdditionalSubtypes() {
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(mContext);
         final String prefAdditionalSubtypes = Settings.readPrefAdditionalSubtypes(
                 prefs, mContext.getResources());
         return AdditionalSubtypeUtils.createAdditionalSubtypesArray(prefAdditionalSubtypes);
diff --git a/java/src/org/kelar/inputmethod/latin/SystemBroadcastReceiver.java b/java/src/org/kelar/inputmethod/latin/SystemBroadcastReceiver.java
index 78c016353..905c5718c 100644
--- a/java/src/org/kelar/inputmethod/latin/SystemBroadcastReceiver.java
+++ b/java/src/org/kelar/inputmethod/latin/SystemBroadcastReceiver.java
@@ -26,7 +26,6 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.database.Cursor;
 import android.os.Process;
-import android.preference.PreferenceManager;
 import android.util.Log;
 import android.view.inputmethod.InputMethodManager;
 import android.view.inputmethod.InputMethodSubtype;
@@ -36,6 +35,7 @@ import org.kelar.inputmethod.dictionarypack.DownloadManagerWrapper;
 import org.kelar.inputmethod.keyboard.KeyboardLayoutSet;
 import org.kelar.inputmethod.latin.settings.Settings;
 import org.kelar.inputmethod.latin.setup.SetupActivity;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.UncachedInputMethodManagerUtils;
 
 /**
@@ -148,7 +148,7 @@ public final class SystemBroadcastReceiver extends BroadcastReceiver {
         if (Log.isLoggable(TAG, Log.INFO)) {
             Log.i(TAG, "toggleAppIcon() : FLAG_SYSTEM = " + isSystemApp);
         }
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(context);
         context.getPackageManager().setComponentEnabledSetting(
                 new ComponentName(context, SetupActivity.class),
                 Settings.readShowSetupWizardIcon(prefs, context)
diff --git a/java/src/org/kelar/inputmethod/latin/accounts/AccountsChangedReceiver.java b/java/src/org/kelar/inputmethod/latin/accounts/AccountsChangedReceiver.java
index e6ca1f606..8ab4c3c23 100644
--- a/java/src/org/kelar/inputmethod/latin/accounts/AccountsChangedReceiver.java
+++ b/java/src/org/kelar/inputmethod/latin/accounts/AccountsChangedReceiver.java
@@ -21,12 +21,12 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
-import android.preference.PreferenceManager;
 import android.text.TextUtils;
 import android.util.Log;
 
 import org.kelar.inputmethod.annotations.UsedForTesting;
 import org.kelar.inputmethod.latin.settings.LocalSettingsConstants;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 
 /**
  * {@link BroadcastReceiver} for {@link AccountManager#LOGIN_ACCOUNTS_CHANGED_ACTION}.
@@ -45,7 +45,7 @@ public class AccountsChangedReceiver extends BroadcastReceiver {
         // that wasn't being backed up and restored, however the preference fragments
         // currently only deal with the default shared preferences which is why
         // separating this out into a different file is not trivial currently.
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(context);
         final String currentAccount = prefs.getString(
                 LocalSettingsConstants.PREF_ACCOUNT_NAME, null);
         removeUnknownAccountFromPreference(prefs, getAccountsForLogin(context), currentAccount);
diff --git a/java/src/org/kelar/inputmethod/latin/settings/AdvancedSettingsFragment.java b/java/src/org/kelar/inputmethod/latin/settings/AdvancedSettingsFragment.java
index 9f3df399e..fd487cb91 100644
--- a/java/src/org/kelar/inputmethod/latin/settings/AdvancedSettingsFragment.java
+++ b/java/src/org/kelar/inputmethod/latin/settings/AdvancedSettingsFragment.java
@@ -26,6 +26,7 @@ import android.preference.ListPreference;
 import org.kelar.inputmethod.latin.AudioAndHapticFeedbackManager;
 import org.kelar.inputmethod.latin.R;
 import org.kelar.inputmethod.latin.SystemBroadcastReceiver;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 
 /**
  * "Advanced" settings sub screen.
@@ -52,7 +53,7 @@ public final class AdvancedSettingsFragment extends SubScreenFragment {
         // initialization method of these classes here. See {@link LatinIME#onCreate()}.
         AudioAndHapticFeedbackManager.init(context);
 
-        final SharedPreferences prefs = getPreferenceManager().getSharedPreferences();
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(context);
 
         if (!Settings.isInternal(prefs)) {
             removePreference(Settings.SCREEN_DEBUG);
@@ -95,7 +96,7 @@ public final class AdvancedSettingsFragment extends SubScreenFragment {
     @Override
     public void onResume() {
         super.onResume();
-        final SharedPreferences prefs = getPreferenceManager().getSharedPreferences();
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(getActivity());
         updateListPreferenceSummaryToCurrentValue(Settings.PREF_KEY_PREVIEW_POPUP_DISMISS_DELAY);
     }
 
diff --git a/java/src/org/kelar/inputmethod/latin/settings/CustomInputStyleSettingsFragment.java b/java/src/org/kelar/inputmethod/latin/settings/CustomInputStyleSettingsFragment.java
index 2e83719f2..dbaff67b8 100644
--- a/java/src/org/kelar/inputmethod/latin/settings/CustomInputStyleSettingsFragment.java
+++ b/java/src/org/kelar/inputmethod/latin/settings/CustomInputStyleSettingsFragment.java
@@ -43,6 +43,7 @@ import org.kelar.inputmethod.latin.RichInputMethodManager;
 import org.kelar.inputmethod.latin.utils.AdditionalSubtypeUtils;
 import org.kelar.inputmethod.latin.utils.DialogUtils;
 import org.kelar.inputmethod.latin.utils.IntentUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.SubtypeLocaleUtils;
 
 import java.util.ArrayList;
@@ -95,7 +96,7 @@ public final class CustomInputStyleSettingsFragment extends PreferenceFragment
     public void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        mPrefs = getPreferenceManager().getSharedPreferences();
+        mPrefs = PreferenceUtils.getDefaultSharedPreferences(getActivity());
         RichInputMethodManager.init(getActivity());
         mRichImm = RichInputMethodManager.getInstance();
         addPreferencesFromResource(R.xml.additional_subtype_settings);
diff --git a/java/src/org/kelar/inputmethod/latin/settings/Settings.java b/java/src/org/kelar/inputmethod/latin/settings/Settings.java
index c16caddb2..62f87c9f7 100644
--- a/java/src/org/kelar/inputmethod/latin/settings/Settings.java
+++ b/java/src/org/kelar/inputmethod/latin/settings/Settings.java
@@ -22,7 +22,6 @@ import android.content.pm.ApplicationInfo;
 import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.os.Build;
-import android.preference.PreferenceManager;
 import android.util.Log;
 
 import org.kelar.inputmethod.compat.BuildCompatUtils;
@@ -31,6 +30,7 @@ import org.kelar.inputmethod.latin.InputAttributes;
 import org.kelar.inputmethod.latin.R;
 import org.kelar.inputmethod.latin.common.StringUtils;
 import org.kelar.inputmethod.latin.utils.AdditionalSubtypeUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.ResourceUtils;
 import org.kelar.inputmethod.latin.utils.RunInLocale;
 import org.kelar.inputmethod.latin.utils.StatsUtils;
@@ -143,7 +143,7 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     private void onCreate(final Context context) {
         mContext = context;
         mRes = context.getResources();
-        mPrefs = PreferenceManager.getDefaultSharedPreferences(context);
+        mPrefs = PreferenceUtils.getDefaultSharedPreferences(context);
         mPrefs.registerOnSharedPreferenceChangeListener(this);
         upgradeAutocorrectionSettings(mPrefs, mRes);
     }
diff --git a/java/src/org/kelar/inputmethod/latin/settings/SubScreenFragment.java b/java/src/org/kelar/inputmethod/latin/settings/SubScreenFragment.java
index 08c9bd441..9e3edabda 100644
--- a/java/src/org/kelar/inputmethod/latin/settings/SubScreenFragment.java
+++ b/java/src/org/kelar/inputmethod/latin/settings/SubScreenFragment.java
@@ -21,6 +21,7 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.content.res.Resources;
+import android.os.Build;
 import android.os.Bundle;
 import android.preference.ListPreference;
 import android.preference.Preference;
@@ -28,6 +29,9 @@ import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
 import android.util.Log;
 
+import org.kelar.inputmethod.compat.BuildCompatUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
+
 /**
  * A base abstract class for a {@link PreferenceFragment} that implements a nested
  * {@link PreferenceScreen} of the main preference screen.
@@ -77,7 +81,7 @@ public abstract class SubScreenFragment extends PreferenceFragment
     }
 
     final SharedPreferences getSharedPreferences() {
-        return getPreferenceManager().getSharedPreferences();
+        return PreferenceUtils.getDefaultSharedPreferences(getActivity());
     }
 
     /**
@@ -100,6 +104,9 @@ public abstract class SubScreenFragment extends PreferenceFragment
     @Override
     public void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        if (BuildCompatUtils.EFFECTIVE_SDK_INT >= Build.VERSION_CODES.N) {
+            super.getPreferenceManager().setStorageDeviceProtected();
+        }
         mSharedPreferenceChangeListener = new OnSharedPreferenceChangeListener() {
             @Override
             public void onSharedPreferenceChanged(final SharedPreferences prefs, final String key) {
diff --git a/java/src/org/kelar/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java b/java/src/org/kelar/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
index fb53b92d7..fe644850f 100644
--- a/java/src/org/kelar/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
+++ b/java/src/org/kelar/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
@@ -18,7 +18,6 @@ package org.kelar.inputmethod.latin.spellcheck;
 
 import android.content.Intent;
 import android.content.SharedPreferences;
-import android.preference.PreferenceManager;
 import android.service.textservice.SpellCheckerService;
 import android.text.InputType;
 import android.view.inputmethod.EditorInfo;
@@ -37,6 +36,7 @@ import org.kelar.inputmethod.latin.SuggestedWords;
 import org.kelar.inputmethod.latin.common.ComposedData;
 import org.kelar.inputmethod.latin.settings.SettingsValuesForSuggestion;
 import org.kelar.inputmethod.latin.utils.AdditionalSubtypeUtils;
+import org.kelar.inputmethod.latin.utils.PreferenceUtils;
 import org.kelar.inputmethod.latin.utils.ScriptUtils;
 import org.kelar.inputmethod.latin.utils.SuggestionResults;
 
@@ -95,7 +95,7 @@ public final class AndroidSpellCheckerService extends SpellCheckerService
         super.onCreate();
         mRecommendedThreshold = Float.parseFloat(
                 getString(R.string.spellchecker_recommended_threshold_value));
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+        final SharedPreferences prefs = PreferenceUtils.getDefaultSharedPreferences(this);
         prefs.registerOnSharedPreferenceChangeListener(this);
         onSharedPreferenceChanged(prefs, PREF_USE_CONTACTS_KEY);
     }
diff --git a/java/src/org/kelar/inputmethod/latin/utils/ImportantNoticeUtils.java b/java/src/org/kelar/inputmethod/latin/utils/ImportantNoticeUtils.java
index d006cd3d5..d552fc241 100644
--- a/java/src/org/kelar/inputmethod/latin/utils/ImportantNoticeUtils.java
+++ b/java/src/org/kelar/inputmethod/latin/utils/ImportantNoticeUtils.java
@@ -71,7 +71,7 @@ public final class ImportantNoticeUtils {
 
     @UsedForTesting
     static SharedPreferences getImportantNoticePreferences(final Context context) {
-        return context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
+        return PreferenceUtils.getSharedPreferences(context, PREFERENCE_NAME);
     }
 
     @UsedForTesting
diff --git a/java/src/org/kelar/inputmethod/latin/utils/PreferenceUtils.java b/java/src/org/kelar/inputmethod/latin/utils/PreferenceUtils.java
new file mode 100644
index 000000000..e0060051b
--- /dev/null
+++ b/java/src/org/kelar/inputmethod/latin/utils/PreferenceUtils.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2024 Amin Bandali <bandali@kelar.org>
+ *
+ * This file is part of Kelar Keyboard.
+ *
+ * Kelar Keyboard is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * Kelar Keyboard is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Kelar Keyboard.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+package org.kelar.inputmethod.latin.utils;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.os.Build;
+import android.util.Log;
+
+import org.kelar.inputmethod.compat.BuildCompatUtils;
+import org.kelar.inputmethod.latin.BuildConfig;
+
+public class PreferenceUtils {
+    static final String TAG = PreferenceUtils.class.getSimpleName();
+    private static final int DOES_NOT_EXIST = -1;
+    private static final String PREF_MOVEDTODPS_SUFFIX = "_movedtodps";
+
+    public static SharedPreferences getSharedPreferences(Context context, String name, int mode) {
+        Context storageContext = context;
+        if (BuildCompatUtils.EFFECTIVE_SDK_INT >= Build.VERSION_CODES.N) {
+            final Context deviceContext;
+            if (context.isDeviceProtectedStorage()) {
+                deviceContext = context;
+            } else {
+                deviceContext = context.createDeviceProtectedStorageContext();
+            }
+            final String pref_name = name + PREF_MOVEDTODPS_SUFFIX;
+            if (deviceContext.getSharedPreferences(name, mode)
+                    .getInt(pref_name, DOES_NOT_EXIST) == DOES_NOT_EXIST) {
+                if (deviceContext.moveSharedPreferencesFrom(context, name)) {
+                    deviceContext.getSharedPreferences(name, mode)
+                            .edit()
+                            .putInt(pref_name, BuildConfig.VERSION_CODE)
+                            .apply();
+                } else {
+                    Log.w(TAG, String.format("Failed to migrate shared preferences %s.", name));
+                }
+            }
+            storageContext = deviceContext;
+        }
+        return storageContext.getSharedPreferences(name, mode);
+    }
+
+    public static SharedPreferences getSharedPreferences(Context context, String name) {
+        return getSharedPreferences(context, name, getDefaultSharedPreferencesMode());
+    }
+
+    public static SharedPreferences getDefaultSharedPreferences(Context context) {
+        return getSharedPreferences(context, getDefaultSharedPreferencesName(context));
+    }
+
+    private static String getDefaultSharedPreferencesName(Context context) {
+        return context.getPackageName() + "_preferences";
+    }
+
+    private static int getDefaultSharedPreferencesMode() {
+        return Context.MODE_PRIVATE;
+    }
+}