Re: [PATCH v2 4/5] bootstd: Add a bootmeth for Android
On Thu 13 Jun 2024 at 16:18, Mattijs Korpershoek
wrote:
> Android boot flow is a bit different than a regular Linux distro.
> Android relies on multiple partitions in order to boot.
>
> A typical boot flow would be:
> 1. Parse the Bootloader Control Block (BCB, misc partition)
> 2. If BCB requested bootonce-bootloader, start fastboot and wait.
> 3. If BCB requested recovery or normal android, run the following:
> 3.a. Get slot (A/B) from BCB
> 3.b. Run AVB (Android Verified Boot) on boot partitions
> 3.c. Load boot and vendor_boot partitions
> 3.d. Load device-tree, ramdisk and boot
>
> The AOSP documentation has more details at [1], [2], [3]
>
> This has been implemented via complex boot scripts such as [4].
> However, these boot script are neither very maintainable nor generic.
> Moreover, DISTRO_DEFAULTS is being deprecated [5].
>
> Add a generic Android bootflow implementation for bootstd.
> For this initial version, only boot image v4 is supported.
>
> [1] https://source.android.com/docs/core/architecture/bootloader
> [2] https://source.android.com/docs/core/architecture/partitions
> [3] https://source.android.com/docs/core/architecture/partitions/generic-boot
> [4]
> https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
> [5] https://lore.kernel.org/r/all/20230914165615.1058529-17-...@chromium.org/
>
> Reviewed-by: Simon Glass
> Signed-off-by: Mattijs Korpershoek
> ---
> MAINTAINERS | 7 +
> boot/Kconfig| 16 ++
> boot/Makefile | 2 +
> boot/bootmeth_android.c | 553
>
> boot/bootmeth_android.h | 29 +++
> doc/develop/bootstd.rst | 6 +
> 6 files changed, 613 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 66783d636e3d..6d2b87720565 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -939,6 +939,13 @@ F: include/bootstd.h
> F: net/eth_bootdevice.c
> F: test/boot/
>
> +BOOTMETH_ANDROID
> +M: Mattijs Korpershoek
> +S: Maintained
> +T: git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
> +F: boot/bootmeth_android.c
> +F: boot/bootmeth_android.h
> +
> BTRFS
> M: Marek Beh.n
> R: Qu Wenruo
> diff --git a/boot/Kconfig b/boot/Kconfig
> index 6f3096c15a6f..88266c8d2ed3 100644
> --- a/boot/Kconfig
> +++ b/boot/Kconfig
> @@ -494,6 +494,22 @@ config BOOTMETH_GLOBAL
> EFI bootmgr, since they take full control over which bootdevs are
> selected to boot.
>
> +config BOOTMETH_ANDROID
> + bool "Bootdev support for Android"
> + depends on X86 || ARM || SANDBOX
> + select ANDROID_AB
> + select ANDROID_BOOT_IMAGE
> + select CMD_BCB
> + select CMD_FASTBOOT
> + select PARTITION_TYPE_GUID
> + select PARTITION_UUIDS
> + help
> + Enables support for booting Android using bootstd. Android requires
> + multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
> +
> + Note that only MMC bootdevs are supported at present. This is caused
> + by AVB being limited to MMC devices only.
> +
> config BOOTMETH_CROS
> bool "Bootdev support for Chromium OS"
> depends on X86 || ARM || SANDBOX
> diff --git a/boot/Makefile b/boot/Makefile
> index 84ccfeaecec4..75d1cd46fabf 100644
> --- a/boot/Makefile
> +++ b/boot/Makefile
> @@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) +=
> vbe_request.o
> obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
> obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
> obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
> +
> +obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
> diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
> new file mode 100644
> index ..6e8d3e615db0
> --- /dev/null
> +++ b/boot/bootmeth_android.c
> @@ -0,0 +1,553 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Bootmeth for Android
> + *
> + * Copyright (C) 2024 BayLibre, SAS
> + * Written by Mattijs Korpershoek
> + */
> +#define LOG_CATEGORY UCLASS_BOOTSTD
> +
> +#include
> +#include
> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
> +#include
> +#endif
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include "bootmeth_android.h"
> +
> +#define BCB_FIELD_COMMAND_SZ 32
> +#define BCB_PART_NAME "misc"
> +#define BOOT_PART_NAME "boot"
> +#define VENDOR_BOOT_PART_NAME "vendor_boot"
> +
> +/**
> + * struct android_priv - Private data
> + *
> + * This is read from the disk and recorded for use when the full Android
> + * kernel must be loaded and booted
> + *
> + * @boot_mode: Requested boot mode (normal, recovery, bootloader)
> + * @slot: Nul-terminated partition slot suffix read from BCB ("a\0" or "b\0")
> + * @header_version: Android boot image header version
> + */
> +struct android_priv {
> + enum android_boot_mode boot_mode;
> + char slot[2];
> + u32
[PATCH v2 4/5] bootstd: Add a bootmeth for Android
Android boot flow is a bit different than a regular Linux distro.
Android relies on multiple partitions in order to boot.
A typical boot flow would be:
1. Parse the Bootloader Control Block (BCB, misc partition)
2. If BCB requested bootonce-bootloader, start fastboot and wait.
3. If BCB requested recovery or normal android, run the following:
3.a. Get slot (A/B) from BCB
3.b. Run AVB (Android Verified Boot) on boot partitions
3.c. Load boot and vendor_boot partitions
3.d. Load device-tree, ramdisk and boot
The AOSP documentation has more details at [1], [2], [3]
This has been implemented via complex boot scripts such as [4].
However, these boot script are neither very maintainable nor generic.
Moreover, DISTRO_DEFAULTS is being deprecated [5].
Add a generic Android bootflow implementation for bootstd.
For this initial version, only boot image v4 is supported.
[1] https://source.android.com/docs/core/architecture/bootloader
[2] https://source.android.com/docs/core/architecture/partitions
[3] https://source.android.com/docs/core/architecture/partitions/generic-boot
[4]
https://source.denx.de/u-boot/u-boot/-/blob/master/include/configs/meson64_android.h
[5] https://lore.kernel.org/r/all/20230914165615.1058529-17-...@chromium.org/
Reviewed-by: Simon Glass
Signed-off-by: Mattijs Korpershoek
---
MAINTAINERS | 7 +
boot/Kconfig| 16 ++
boot/Makefile | 2 +
boot/bootmeth_android.c | 553
boot/bootmeth_android.h | 29 +++
doc/develop/bootstd.rst | 6 +
6 files changed, 613 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 66783d636e3d..6d2b87720565 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -939,6 +939,13 @@ F: include/bootstd.h
F: net/eth_bootdevice.c
F: test/boot/
+BOOTMETH_ANDROID
+M: Mattijs Korpershoek
+S: Maintained
+T: git https://source.denx.de/u-boot/custodians/u-boot-dfu.git
+F: boot/bootmeth_android.c
+F: boot/bootmeth_android.h
+
BTRFS
M: Marek Behún
R: Qu Wenruo
diff --git a/boot/Kconfig b/boot/Kconfig
index 6f3096c15a6f..88266c8d2ed3 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -494,6 +494,22 @@ config BOOTMETH_GLOBAL
EFI bootmgr, since they take full control over which bootdevs are
selected to boot.
+config BOOTMETH_ANDROID
+ bool "Bootdev support for Android"
+ depends on X86 || ARM || SANDBOX
+ select ANDROID_AB
+ select ANDROID_BOOT_IMAGE
+ select CMD_BCB
+ select CMD_FASTBOOT
+ select PARTITION_TYPE_GUID
+ select PARTITION_UUIDS
+ help
+ Enables support for booting Android using bootstd. Android requires
+ multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
+
+ Note that only MMC bootdevs are supported at present. This is caused
+ by AVB being limited to MMC devices only.
+
config BOOTMETH_CROS
bool "Bootdev support for Chromium OS"
depends on X86 || ARM || SANDBOX
diff --git a/boot/Makefile b/boot/Makefile
index 84ccfeaecec4..75d1cd46fabf 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -66,3 +66,5 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_REQUEST) += vbe_request.o
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
+
+obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_ANDROID) += bootmeth_android.o
diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c
new file mode 100644
index ..6e8d3e615db0
--- /dev/null
+++ b/boot/bootmeth_android.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootmeth for Android
+ *
+ * Copyright (C) 2024 BayLibre, SAS
+ * Written by Mattijs Korpershoek
+ */
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include
+#include
+#if CONFIG_IS_ENABLED(AVB_VERIFY)
+#include
+#endif
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include "bootmeth_android.h"
+
+#define BCB_FIELD_COMMAND_SZ 32
+#define BCB_PART_NAME "misc"
+#define BOOT_PART_NAME "boot"
+#define VENDOR_BOOT_PART_NAME "vendor_boot"
+
+/**
+ * struct android_priv - Private data
+ *
+ * This is read from the disk and recorded for use when the full Android
+ * kernel must be loaded and booted
+ *
+ * @boot_mode: Requested boot mode (normal, recovery, bootloader)
+ * @slot: Nul-terminated partition slot suffix read from BCB ("a\0" or "b\0")
+ * @header_version: Android boot image header version
+ */
+struct android_priv {
+ enum android_boot_mode boot_mode;
+ char slot[2];
+ u32 header_version;
+};
+
+static int android_check(struct udevice *dev, struct bootflow_iter *iter)
+{
+ /* This only works on mmc devices */
+ if (bootflow_iter_check_mmc(iter))
+ return log_msg_ret("mmc", -ENOTSUPP);
+
+ /*
+* This only works on whole devices, as
