[PATCH v1] include: android_bootloader_message.h: sync with AOSP upstream
Mattijs Korpershoek
mkorpershoek at baylibre.com
Thu Mar 7 10:32:45 CET 2024
Hi Igor, Sam,
On mar., févr. 20, 2024 at 20:08, Igor Opaniuk <igor.opaniuk at foundries.io> wrote:
> Hi Sam,
>
> On Tue, Feb 20, 2024 at 7:29 PM Sam Protsenko
> <semen.protsenko at linaro.org> wrote:
>>
>> On Mon, Feb 19, 2024 at 4:16 AM Igor Opaniuk <igor.opaniuk at gmail.com> wrote:
>> >
>> > This takes the latest changes from AOSP from [1][2] (as this
>> > header was split on two) with minimal changes (this could lead
>> > to warnings reported by checkpatch).
>>
>> Do we want to maybe follow that and also carry two different headers
>> in U-Boot? Or it doesn't make much sense? I'm thinking in terms of
>> future portability mostly: how easy it's to update this header right
>> now, and how easy it's going to be further. I didn't form any opinion
>> on that, hence asking.
> The problem is licensing. android_bootloader_message.h was
> re-licensed by Alex Deymo from Google under BSD-3-Clause,
> which is GPLv2 compatible. I'm not sure it's legally correct to pull
> boot_control_definition.h from AOSP licensed under Apache as a
> separate file.
I'd prefer a separate file as well but I'm not familiar enough with
licensing to see if that's a problem.
I'm ok to keep as is.
>
>>
>> Another thing: are you sure that changing only the header won't break
>> anything in U-Boot .c files that use this header?
>
> I've tested both ab_select and avb verify in QEMU. Or do you mean
> something else additionally should be tested?
I've boot tested this on VIM3 and tested adb reboot bootloader, adb
reboot fastboot (which writes things into the misc partition)
>
>>
>> >
>> > Some local changes have been applied:
>>
>> Is it possible to split this work into two patches:
>> 1. Bring the original changes only
>> 2. Apply all necessary changes for U-Boot
>>
>> Or does it break the build, etc? Again, thinking in terms of
>> portability easiness, and not sure which approach is better -- just
>> asking basically.
> Yeah, that's the problem, as splitting this on two commits
> will lead to the first one reporting warnings/notes.
>
>>
>> > 1. Enable static_assert() for defined structures to be sure
>> > that all of them have correct sizes.
>> > 2. Adjuste types in bootloader_control structure with bitfields
>>
>> Adjuste -> adjust
> Will fix, thanks!
>>
>> > (uint8_t -> uint16_t). It seems that gcc just doesn't like bitfields
>>
>> I wonder if all those extra changes can be upstreamed back to AOSP?
>> Ideally we'd want to just copy those headers over from AOSP to U-Boot
>> with no changes, would make the porting work easier. What are your
>> thoughts on that?
> Technically we can, I was planning to do that.
I'm not sure this change will be of interest to AOSP, since they moved
to the AIDL implementation here:
https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/main/boot/aidl/default/
If you submit it on gerrit, can you please cc me? (using this email address)
>
>>
>> > that cross the width of the type. Changing the type doesn't change
>> > the layout though.
>> > This addresses this gcc note:
>> > In file included from boot/android_ab.c:7:
>> > include/android_bootloader_message.h:230:1: note: offset of packed bit-field ‘merge_status’ has changed in GCC 4.4
>> > 230 | } __attribute__((packed));
>> >
>> > [1] https://android.googlesource.com/platform/bootable/recovery/+/main/bootloader_message/include/bootloader_message/bootloader_message.h
>> > [2] https://android.googlesource.com/platform/hardware/interfaces/+/main/boot/1.1/default/boot_control/include/private/boot_control_definition.h
>> >
>> > CC: Alex Deymo <deymo at google.com>
>> > CC: Sam Protsenko <semen.protsenko at linaro.org>
>> > CC: Eugeniu Rosca <erosca at de.adit-jv.com>
>> > CC: Simon Glass <sjg at chromium.org>
>> > Signed-off-by: Igor Opaniuk <igor.opaniuk at gmail.com>
>> > ---
>> >
>> > include/android_bootloader_message.h | 104 +++++++++++++++++++++++----
>> > 1 file changed, 92 insertions(+), 12 deletions(-)
>> >
>> > diff --git a/include/android_bootloader_message.h b/include/android_bootloader_message.h
>> > index 286d7ab0f31..75198fc9dc2 100644
>> > --- a/include/android_bootloader_message.h
>> > +++ b/include/android_bootloader_message.h
>> > @@ -21,17 +21,22 @@
>> > * stddef.h
>> > */
>> > #include <compiler.h>
>> > +#include <linux/build_bug.h>
>> > #endif
>> >
>> > // Spaces used by misc partition are as below:
>> > // 0 - 2K For bootloader_message
>> > // 2K - 16K Used by Vendor's bootloader (the 2K - 4K range may be optionally used
>> > // as bootloader_message_ab struct)
>> > -// 16K - 64K Used by uncrypt and recovery to store wipe_package for A/B devices
>> > +// 16K - 32K Used by uncrypt and recovery to store wipe_package for A/B devices
>> > +// 32K - 64K System space, used for miscellanious AOSP features. See below.
>> > // Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
>> > // are not configurable without changing all of them.
>> > static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
>> > +static const size_t VENDOR_SPACE_OFFSET_IN_MISC = 2 * 1024;
>> > static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
>> > +static const size_t SYSTEM_SPACE_OFFSET_IN_MISC = 32 * 1024;
>> > +static const size_t SYSTEM_SPACE_SIZE_IN_MISC = 32 * 1024;
>> >
>> > /* Bootloader Message (2-KiB)
>> > *
>> > @@ -81,24 +86,67 @@ struct bootloader_message {
>> > char reserved[1184];
>> > };
>> >
>> > +// Holds Virtual A/B merge status information. Current version is 1. New fields
>> > +// must be added to the end.
>> > +struct misc_virtual_ab_message {
>> > + uint8_t version;
>> > + uint32_t magic;
>> > + uint8_t merge_status; // IBootControl 1.1, MergeStatus enum.
>> > + uint8_t source_slot; // Slot number when merge_status was written.
>> > + uint8_t reserved[57];
>> > +} __attribute__((packed));
>> > +
>> > +struct misc_memtag_message {
>> > + uint8_t version;
>> > + uint32_t magic; // magic string for treble compat
>> > + uint32_t memtag_mode;
>> > + uint8_t reserved[55];
>> > +} __attribute__((packed));
>> > +
>> > +struct misc_kcmdline_message {
>> > + uint8_t version;
>> > + uint32_t magic;
>> > + uint64_t kcmdline_flags;
>> > + uint8_t reserved[51];
>> > +} __attribute__((packed));
>> > +
>> > +#define MISC_VIRTUAL_AB_MESSAGE_VERSION 2
>> > +#define MISC_VIRTUAL_AB_MAGIC_HEADER 0x56740AB0
>> > +
>> > +#define MISC_MEMTAG_MESSAGE_VERSION 1
>> > +#define MISC_MEMTAG_MAGIC_HEADER 0x5afefe5a
>> > +#define MISC_MEMTAG_MODE_MEMTAG 0x1
>> > +#define MISC_MEMTAG_MODE_MEMTAG_ONCE 0x2
>> > +#define MISC_MEMTAG_MODE_MEMTAG_KERNEL 0x4
>> > +#define MISC_MEMTAG_MODE_MEMTAG_KERNEL_ONCE 0x8
>> > +#define MISC_MEMTAG_MODE_MEMTAG_OFF 0x10
>> > +// This is set when the state was overridden forcibly. This does not need to be
>> > +// interpreted by the bootloader but is only for bookkeeping purposes so
>> > +// userspace knows what to do when the override is undone.
>> > +// See system/extras/mtectrl in AOSP for more information.
>> > +#define MISC_MEMTAG_MODE_FORCED 0x20
>> > +
>> > +#define MISC_KCMDLINE_MESSAGE_VERSION 1
>> > +#define MISC_KCMDLINE_MAGIC_HEADER 0x6ab5110c
>> > +#define MISC_KCMDLINE_BINDER_RUST 0x1
>> > /**
>> > * We must be cautious when changing the bootloader_message struct size,
>> > * because A/B-specific fields may end up with different offsets.
>> > */
>> > -#ifndef __UBOOT__
>> > +
>> > #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
>> > static_assert(sizeof(struct bootloader_message) == 2048,
>> > "struct bootloader_message size changes, which may break A/B devices");
>> > #endif
>> > -#endif /* __UBOOT__ */
>> >
>> > /**
>> > * The A/B-specific bootloader message structure (4-KiB).
>> > *
>> > * We separate A/B boot control metadata from the regular bootloader
>> > * message struct and keep it here. Everything that's A/B-specific
>> > - * stays after struct bootloader_message, which should be managed by
>> > - * the A/B-bootloader or boot control HAL.
>> > + * stays after struct bootloader_message, which belongs to the vendor
>> > + * space of /misc partition. Also, the A/B-specific contents should be
>> > + * managed by the A/B-bootloader or boot control HAL.
>> > *
>> > * The slot_suffix field is used for A/B implementations where the
>> > * bootloader does not set the androidboot.ro.boot.slot_suffix kernel
>> > @@ -124,12 +172,10 @@ struct bootloader_message_ab {
>> > * Be cautious about the struct size change, in case we put anything post
>> > * bootloader_message_ab struct (b/29159185).
>> > */
>> > -#ifndef __UBOOT__
>> > #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
>> > static_assert(sizeof(struct bootloader_message_ab) == 4096,
>> > "struct bootloader_message_ab size changes");
>> > #endif
>> > -#endif /* __UBOOT__ */
>> >
>> > #define BOOT_CTRL_MAGIC 0x42414342 /* Bootloader Control AB */
>> > #define BOOT_CTRL_VERSION 1
>> > @@ -165,11 +211,13 @@ struct bootloader_control {
>> > // Version of struct being used (see BOOT_CTRL_VERSION).
>> > uint8_t version;
>> > // Number of slots being managed.
>> > - uint8_t nb_slot : 3;
>> > + uint16_t nb_slot : 3;
>> > // Number of times left attempting to boot recovery.
>> > - uint8_t recovery_tries_remaining : 3;
>> > + uint16_t recovery_tries_remaining : 3;
>> > + // Status of any pending snapshot merge of dynamic partitions.
>> > + uint16_t merge_status : 3;
>> > // Ensure 4-bytes alignment for slot_info field.
>> > - uint8_t reserved0[2];
>> > + uint8_t reserved0[1];
>> > // Per-slot information. Up to 4 slots.
>> > struct slot_metadata slot_info[4];
>> > // Reserved for further use.
>> > @@ -179,25 +227,46 @@ struct bootloader_control {
>> > uint32_t crc32_le;
>> > } __attribute__((packed));
>> >
>> > -#ifndef __UBOOT__
>> > #if (__STDC_VERSION__ >= 201112L) || defined(__cplusplus)
>> > static_assert(sizeof(struct bootloader_control) ==
>> > sizeof(((struct bootloader_message_ab *)0)->slot_suffix),
>> > "struct bootloader_control has wrong size");
>> > +static_assert(sizeof(struct misc_virtual_ab_message) == 64,
>> > + "struct misc_virtual_ab_message has wrong size");
>> > +static_assert(sizeof(struct misc_memtag_message) == 64,
>> > + "struct misc_memtag_message has wrong size");
>> > +static_assert(sizeof(struct misc_kcmdline_message) == 64,
>> > + "struct misc_kcmdline_message has wrong size");
>> > #endif
>> > -#endif /* __UBOOT__ */
>> >
>> > #ifndef __UBOOT__
>> > +
>> > +// This struct is not meant to be used directly, rather, it is to make
>> > +// computation of offsets easier. New fields must be added to the end.
>> > +struct misc_system_space_layout {
>> > + misc_virtual_ab_message virtual_ab_message;
>> > + misc_memtag_message memtag_message;
>> > + misc_kcmdline_message kcmdline_message;
>> > +} __attribute__((packed));
>> > +
>> > #ifdef __cplusplus
>> >
>> > #include <string>
>> > #include <vector>
>> >
>> > +// Gets the block device name of /misc partition.
>> > +std::string get_misc_blk_device(std::string* err);
>> > +
>> > // Return the block device name for the bootloader message partition and waits
>> > // for the device for up to 10 seconds. In case of error returns the empty
>> > // string.
>> > std::string get_bootloader_message_blk_device(std::string* err);
>> >
>> > +// Writes |size| bytes of data from buffer |p| to |misc_blk_device| at |offset|. If the write fails,
>> > +// sets the error message in |err|.
>> > +bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
>> > + size_t offset, std::string* err);
>> > +
>> > // Read bootloader message into boot. Error message will be set in err.
>> > bool read_bootloader_message(bootloader_message* boot, std::string* err);
>> >
>> > @@ -242,6 +311,17 @@ bool read_wipe_package(std::string* package_data, size_t size, std::string* err)
>> > // Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC).
>> > bool write_wipe_package(const std::string& package_data, std::string* err);
>> >
>> > +// Read or write the Virtual A/B message from system space in /misc.
>> > +bool ReadMiscVirtualAbMessage(misc_virtual_ab_message* message, std::string* err);
>> > +bool WriteMiscVirtualAbMessage(const misc_virtual_ab_message& message, std::string* err);
>> > +
>> > +// Read or write the memtag message from system space in /misc.
>> > +bool ReadMiscMemtagMessage(misc_memtag_message* message, std::string* err);
>> > +bool WriteMiscMemtagMessage(const misc_memtag_message& message, std::string* err);
>> > +
>> > +// Read or write the kcmdline message from system space in /misc.
>> > +bool ReadMiscKcmdlineMessage(misc_kcmdline_message* message, std::string* err);
>> > +bool WriteMiscKcmdlineMessage(const misc_kcmdline_message& message, std::string* err);
>>
>> AFAIU, these new prototypes brought by this patch don't have actual
>> implementation yet. Does it affect the build somehow, e.g. maybe
>> causing some build warnings? Or is the build log clean?
>
> They are all wrapped with #ifndef __UBOOT__.
>
>
>>
>> > #else
>> >
>> > #include <stdbool.h>
>> > --
>> > 2.34.1
>> >
> Thanks for your comments!
>
>
> --
> Best regards - Freundliche Grüsse - Meilleures salutations
>
> Igor Opaniuk
> Senior Software Engineer, Embedded & Security
> E: igor.opaniuk at foundries.io
> W: www.foundries.io
More information about the U-Boot
mailing list