[PATCH 5/6] bootstd: Add a bootmeth for Android
Mattijs Korpershoek
mkorpershoek at baylibre.com
Tue Jun 11 11:32:28 CEST 2024
Hi Igor,
Thank you for your quick review.
On lun., juin 10, 2024 at 17:15, Igor Opaniuk <igor.opaniuk at gmail.com> wrote:
> Hi Mattijs,
>
> On Thu, Jun 6, 2024 at 2:24 PM Mattijs Korpershoek
> <mkorpershoek at baylibre.com> 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-sjg@chromium.org/
>>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
>> ---
>> MAINTAINERS | 7 +
>> boot/Kconfig | 14 ++
>> boot/Makefile | 2 +
>> boot/bootmeth_android.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++
>> boot/bootmeth_android.h | 27 +++
>> doc/develop/bootstd.rst | 6 +
>> 6 files changed, 578 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 <mkorpershoek at baylibre.com>
>> +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 <kabel at kernel.org>
>> R: Qu Wenruo <wqu at suse.com>
>> diff --git a/boot/Kconfig b/boot/Kconfig
>> index 6f3096c15a6f..5fa6f3b8315d 100644
>> --- a/boot/Kconfig
>> +++ b/boot/Kconfig
>> @@ -494,6 +494,20 @@ 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 PARTITION_TYPE_GUID
>> + select PARTITION_UUIDS
>> + help
>> + Enables support for booting Android using bootdevs. Android requires
>> + multiple partitions (misc, boot, vbmeta, ...) in storage for booting.
>> +
>> + Note that only MMC bootdevs are supported at present.
>> +
>> 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 000000000000..26d548d2fd6e
>> --- /dev/null
>> +++ b/boot/bootmeth_android.c
>> @@ -0,0 +1,522 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Bootmethod for Android
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek at baylibre.com>
>> + */
>> +#define LOG_CATEGORY UCLASS_BOOTSTD
>> +
>> +#include <android_ab.h>
>> +#include <android_image.h>
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>> +#include <avb_verify.h>
>> +#endif
>> +#include <bcb.h>
>> +#include <blk.h>
>> +#include <bootflow.h>
>> +#include <bootm.h>
>> +#include <bootmeth.h>
>> +#include <dm.h>
>> +#include <image.h>
>> +#include <malloc.h>
>> +#include <mapmem.h>
>> +#include <part.h>
>> +#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
>> + */
>> +struct android_priv {
>> + int 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 multiple
>> + * partitions are needed to boot Android
>> + */
> Please use Linux kernel coding style for long comments [1].
> Same in all occurrences below
>
> [1] https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
Sorry about that that. Will do.
Odd that running checkpatch with --u-boot did not caught this.
$ ./scripts/checkpatch.pl --strict --u-boot --git HEAD^^..HEAD
>> + if (iter->part != 0)
>> + return log_msg_ret("mmc part", -ENOTSUPP);
>> +
>> + return 0;
>> +}
>> +
>> +static int scan_boot_part(struct udevice *blk, struct android_priv *priv)
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(blk);
>> + struct disk_partition partition;
>> + char partname[PART_NAME_LEN];
>> + ulong num_blks, bufsz;
>> + char *buf;
>> + int ret;
>> +
>> + sprintf(partname, BOOT_PART_NAME "_%s", priv->slot);
>> + ret = part_get_info_by_name(desc, partname, &partition);
>> + if (ret < 0)
>> + return log_msg_ret("part info", ret);
>> +
>> + num_blks = DIV_ROUND_UP(sizeof(struct andr_boot_img_hdr_v0), desc->blksz);
>> + bufsz = num_blks * desc->blksz;
>> + buf = malloc(bufsz);
>> + if (!buf)
>> + return log_msg_ret("buf", -ENOMEM);
>> +
>> + ret = blk_read(blk, partition.start, num_blks, buf);
>> + if (ret != num_blks) {
>> + free(buf);
>> + return log_msg_ret("part read", -EIO);
>> + }
>> +
>> + if (!is_android_boot_image_header(buf)) {
>> + free(buf);
>> + return log_msg_ret("header", -ENOENT);
>> + }
>> +
>> + priv->header_version = android_image_get_version(buf);
>> +
>> + return 0;
> Shouldn't we free(buf) also here?
Yes we should. Will do for v2. Thanks for catching this!
>
>> +}
>> +
>> +static int scan_vendor_boot_part(struct udevice *blk, const char slot[2])
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(blk);
>> + struct disk_partition partition;
>> + char partname[PART_NAME_LEN];
>> + ulong num_blks, bufsz;
>> + char *buf;
>> + int ret;
>> +
>> + sprintf(partname, VENDOR_BOOT_PART_NAME "_%s", slot);
>> + ret = part_get_info_by_name(desc, partname, &partition);
>> + if (ret < 0)
>> + return log_msg_ret("part info", ret);
>> +
>> + num_blks = DIV_ROUND_UP(sizeof(struct andr_vnd_boot_img_hdr), desc->blksz);
>> + bufsz = num_blks * desc->blksz;
>> + buf = malloc(bufsz);
>> + if (!buf)
>> + return log_msg_ret("buf", -ENOMEM);
>> +
>> + ret = blk_read(blk, partition.start, num_blks, buf);
>> + if (ret != num_blks) {
>> + free(buf);
>> + return log_msg_ret("part read", -EIO);
>> + }
>> +
>> + if (!is_android_vendor_boot_image_header(buf)) {
>> + free(buf);
>> + return log_msg_ret("header", -ENOENT);
>> + }
>> +
>> + return 0;
> free(buf)?
Yes we should. Will do for v2. Thanks for catching this!
>
>> +}
>> +
>> +static int android_read_slot_from_bcb(struct bootflow *bflow, bool decrement)
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> + struct android_priv *priv = bflow->bootmeth_priv;
>> + struct disk_partition misc;
>> + char slot_suffix[3];
>> + int ret;
>> +
>> + ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> + if (ret < 0)
>> + return log_msg_ret("part", ret);
>> +
>> + ret = ab_select_slot(desc, &misc, decrement);
>> + if (ret < 0)
>> + return log_msg_ret("slot", ret);
>> +
>> + priv->slot[0] = BOOT_SLOT_NAME(ret);
>> + priv->slot[1] = '\0';
>> +
>> + sprintf(slot_suffix, "_%s", priv->slot);
>> + ret = bootflow_cmdline_set_arg(bflow, "androidboot.slot_suffix",
>> + slot_suffix, false);
>> + if (ret < 0)
>> + return log_msg_ret("slot", ret);
>> +
>> + return 0;
>> +}
>> +
>> +static int configure_serialno(struct bootflow *bflow)
>> +{
>> + char *serialno = env_get("serial#");
>> +
>> + if (!serialno)
>> + return log_msg_ret("serial", -ENOENT);
>> +
>> + return bootflow_cmdline_set_arg(bflow, "androidboot.serialno", serialno, false);
>> +}
>> +
>> +static int android_read_bootflow(struct udevice *dev, struct bootflow *bflow)
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> + struct disk_partition misc;
>> + struct android_priv *priv;
>> + char command[BCB_FIELD_COMMAND_SZ];
>> + int ret;
>> +
>> + bflow->state = BOOTFLOWST_MEDIA;
>> +
>> + /* bcb_find_partition_and_load() will print errors to stdout
>> + * if BCB_PART_NAME is not found. To avoid that, check if the
>> + * partition exists first.
>> + */
>> + ret = part_get_info_by_name(desc, BCB_PART_NAME, &misc);
>> + if (ret < 0)
>> + return log_msg_ret("part", ret);
>> +
>> + ret = bcb_find_partition_and_load("mmc", desc->devnum, BCB_PART_NAME);
>> + if (ret < 0)
>> + return log_msg_ret("bcb load", ret);
>> +
>> + ret = bcb_get(BCB_FIELD_COMMAND, command, sizeof(command));
>> + if (ret < 0)
>> + return log_msg_ret("bcb read", ret);
>> +
>> + priv = malloc(sizeof(struct android_priv));
>> + if (!priv)
>> + return log_msg_ret("buf", -ENOMEM);
>> +
>> + bflow->bootmeth_priv = priv;
> Probably we should do that just before successfully returning from the function,
> otherwise we will end up with a dangling pointer.
Right, thanks for the suggestion. Will do for v2.
>
>> + if (!strcmp("bootonce-bootloader", command)) {
>> + priv->boot_mode = ANDROID_BOOT_MODE_BOOTLOADER;
>> + bflow->os_name = strdup("Android (bootloader)");
>> + } else if (!strcmp("boot-fastboot", command)) {
>> + priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> + bflow->os_name = strdup("Android (fastbootd)");
>> + } else if (!strcmp("boot-recovery", command)) {
>> + priv->boot_mode = ANDROID_BOOT_MODE_RECOVERY;
>> + bflow->os_name = strdup("Android (recovery)");
>> + } else {
>> + priv->boot_mode = ANDROID_BOOT_MODE_NORMAL;
>> + bflow->os_name = strdup("Android");
>> + }
>> + if (!bflow->os_name)
>> + return log_msg_ret("os", -ENOMEM);
>> +
>> + if (priv->boot_mode == ANDROID_BOOT_MODE_BOOTLOADER) {
>> + /* Clear BCB */
>> + memset(command, 0, sizeof(command));
>> + ret = bcb_set(BCB_FIELD_COMMAND, command);
>> + if (ret < 0) {
>> + free(priv);
>> + return log_msg_ret("bcb set", ret);
>> + }
>> + ret = bcb_store();
>> + if (ret < 0) {
>> + free(priv);
>
>> + return log_msg_ret("bcb store", ret);
>> + }
>> +
> is free(bflow->bootmeth_priv) handled in functions that call
> android_read_bootflow() ?
It's not. Future functions (called later) like boot_android() need to
access this structure.
I've modeled this after bootmeth_cros/cros_boot() but I don't
see a reason for not freeing this just before calling bootm().
On the other hand, we will be booting an OS (and this quitting U-Boot)
so it's not entirely needed.
I don't have a strong opinion on this so I can add the free() in
boot_android_normal() and boot_android_bootloader().
>
>> + bflow->state = BOOTFLOWST_READY;
>> + return 0;
>> + }
>> +
>> + /* For recovery and normal boot, we need to scan the partitions */
>> + ret = android_read_slot_from_bcb(bflow, false);
>> + if (ret < 0) {
>> + free(priv);
>> + return log_msg_ret("read slot", ret);
>> + }
>> +
>> + ret = scan_boot_part(bflow->blk, priv);
>> + if (ret < 0) {
>> + printf("- scan boot failed: err=%d\n", ret);
>> + free(priv);
>> + return log_msg_ret("scan boot", ret);
>> + }
>> +
>> + if (priv->header_version != 4) {
>> + printf("- Only boot.img v4 is supported\n");
>> + free(priv);
>> + return log_msg_ret("version", -EINVAL);
>> + }
>> +
>> + ret = scan_vendor_boot_part(bflow->blk, priv->slot);
>> + if (ret < 0) {
>> + printf("- scan vendor_boot failed: err=%d\n", ret);
>> + free(priv);
>> + return log_msg_ret("scan vendor_boot", ret);
>> + }
>> +
>> + /* Ignoring return code: setting serial number is not mandatory for booting */
>> + configure_serialno(bflow);
>> +
>> + if (priv->boot_mode == ANDROID_BOOT_MODE_NORMAL) {
>> + ret = bootflow_cmdline_set_arg(bflow, "androidboot.force_normal_boot", "1", false);
>> + if (ret < 0) {
>> + free(priv);
>> + return log_msg_ret("normal_boot", ret);
>> + }
>> + }
>> +
>> + bflow->state = BOOTFLOWST_READY;
>> +
>> + return 0;
>> +}
>> +
>> +static int android_read_file(struct udevice *dev, struct bootflow *bflow,
>> + const char *file_path, ulong addr, ulong *sizep)
>> +{
>> + /* Reading individual files is not supported since we only
>> + * operate on whole mmc devices (because we require multiple partitions)
>> + */
>> + return log_msg_ret("Unsupported", -ENOSYS);
>> +}
>> +
>> +static int read_slotted_partition(struct blk_desc *desc, const char *const name,
>> + const char slot[2], ulong addr)
>> +{
>> + struct disk_partition partition;
>> + char partname[PART_NAME_LEN];
>> + int ret;
>> + u32 n;
>> +
>> + /* Ensure name fits in partname it should be: <name>_<slot>\0 */
>> + if (strlen(name) > (PART_NAME_LEN - 2 - 1))
>> + return log_msg_ret("name too long", -EINVAL);
>> +
>> + sprintf(partname, "%s_%s", name, slot);
>> + ret = part_get_info_by_name(desc, partname, &partition);
>> + if (ret < 0)
>> + return log_msg_ret("part", ret);
>> +
>> + n = blk_dread(desc, partition.start, partition.size, map_sysmem(addr, 0));
>> + if (n < partition.size)
>> + return log_msg_ret("part read", -EIO);
>> +
>> + return 0;
>> +}
>> +
>> +#if CONFIG_IS_ENABLED(AVB_VERIFY)
>> +static int avb_append_commandline_arg(struct bootflow *bflow, char *arg)
>> +{
>> + char *key = strsep(&arg, "=");
>> + char *value = arg;
>> + int ret;
>> +
>> + ret = bootflow_cmdline_set_arg(bflow, key, value, false);
>> + if (ret < 0)
>> + return log_msg_ret("avb cmdline", ret);
>> +
>> + return 0;
>> +}
>> +
>> +static int avb_append_commandline(struct bootflow *bflow, char *cmdline)
>> +{
>> + char *arg = strsep(&cmdline, " ");
>> + int ret;
>> +
>> + while (arg) {
>> + ret = avb_append_commandline_arg(bflow, arg);
>> + if (ret < 0)
>> + return ret;
>> +
>> + arg = strsep(&cmdline, " ");
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> + struct android_priv *priv = bflow->bootmeth_priv;
>> + const char * const requested_partitions[] = {"boot", "vendor_boot"};
>> + struct AvbOps *avb_ops;
>> + AvbSlotVerifyResult result;
>> + AvbSlotVerifyData *out_data;
>> + enum avb_boot_state boot_state;
>> + char *extra_args;
>> + char slot_suffix[3];
>> + bool unlocked = false;
>> + int ret;
>> +
>> + avb_ops = avb_ops_alloc(desc->devnum);
>> + if (!avb_ops)
>> + return log_msg_ret("avb ops", -ENOMEM);.
>> +
>> + sprintf(slot_suffix, "_%s", priv->slot);
>> +
>> + ret = avb_ops->read_is_device_unlocked(avb_ops, &unlocked);
>> + if (ret != AVB_IO_RESULT_OK)
>> + return log_msg_ret("avb lock", -EIO);
>> +
>> + result = avb_slot_verify(avb_ops,
>> + requested_partitions,
>> + slot_suffix,
>> + unlocked,
>> + AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
>> + &out_data);
>> +
>> + if (result != AVB_SLOT_VERIFY_RESULT_OK) {
>> + printf("Verification failed, reason: %s\n",
>> + str_avb_slot_error(result));
> avb_ops_free(avb_ops) ?
Yes we should. Will do for v2. Thanks for catching this!
>> + return log_msg_ret("avb verify", -EIO);
>> + }
>> +
>> + if (unlocked)
>> + boot_state = AVB_ORANGE;
>> + else
>> + boot_state = AVB_GREEN;
>> +
>> + extra_args = avb_set_state(avb_ops, boot_state);
>> + if (extra_args) {
>> + ret = avb_append_commandline_arg(bflow, extra_args);
>> + if (ret < 0)
>> + goto free_out_data;
>> + }
>> +
>> + ret = avb_append_commandline(bflow, out_data->cmdline);
>> + if (ret < 0)
>> + goto free_out_data;
>> +
>> + return 0;
>> +
>> + free_out_data:
>> + if (out_data)
>> + avb_slot_verify_data_free(out_data);
>> +
>> + return log_msg_ret("avb cmdline", ret);
>> +}
>> +#else
>> +static int run_avb_verification(struct bootflow *bflow)
>> +{
>> + int ret;
>> +
>> + /* When AVB is unsupported, pass ORANGE state */
>> + ret = bootflow_cmdline_set_arg(bflow,
>> + "androidboot.verifiedbootstate",
>> + "orange", false);
>> + if (ret < 0)
>> + return log_msg_ret("avb cmdline", ret);
>> +
>> + return 0;
>> +}
>> +#endif /* AVB_VERIFY */
>> +
>> +static int boot_android_normal(struct bootflow *bflow)
>> +{
>> + struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
>> + struct android_priv *priv = bflow->bootmeth_priv;
>> + int ret;
>> +
>> + ulong loadaddr = env_get_hex("loadaddr", 0);
>> + ulong vloadaddr = env_get_hex("vendor_boot_comp_addr_r", 0);
>> +
>> + ret = run_avb_verification(bflow);
>> + if (ret < 0)
>> + return log_msg_ret("avb", ret);
>> +
>> + /* Read slot once more to decrement counter from BCB */
>> + ret = android_read_slot_from_bcb(bflow, true);
>> + if (ret < 0)
>> + return log_msg_ret("read slot", ret);
>> +
>> + ret = read_slotted_partition(desc, "boot", priv->slot, loadaddr);
>> + if (ret < 0)
>> + return log_msg_ret("read boot", ret);
>> +
>> + ret = read_slotted_partition(desc, "vendor_boot", priv->slot, vloadaddr);
>> + if (ret < 0)
>> + return log_msg_ret("read vendor_boot", ret);
>> +
>> + set_abootimg_addr(loadaddr);
>> + set_avendor_bootimg_addr(vloadaddr);
>> +
>> + ret = bootm_boot_start(loadaddr, bflow->cmdline);
>> +
>> + return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_recovery(struct bootflow *bflow)
>> +{
>> + int ret;
>> +
>> + ret = boot_android_normal(bflow);
>> +
>> + return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int boot_android_bootloader(struct bootflow *bflow)
>> +{
>> + int ret;
>> +
>> + ret = run_command("fastboot usb 0", 0);
> select CMD_FASTBOOT in Kconfig (config BOOTMETH_ANDROID)?
Yes, I will add this for v2. Thank you for the suggestion.
>> + do_reset(NULL, 0, 0, NULL);
>> +
>> + return log_msg_ret("boot", ret);
>> +}
>> +
>> +static int android_boot(struct udevice *dev, struct bootflow *bflow)
>> +{
>> + struct android_priv *priv = bflow->bootmeth_priv;
>> + int ret;
>> +
>> + switch (priv->boot_mode) {
>> + case ANDROID_BOOT_MODE_NORMAL:
>> + ret = boot_android_normal(bflow);
>> + break;
>> + case ANDROID_BOOT_MODE_RECOVERY:
>> + ret = boot_android_recovery(bflow);
>> + break;
>> + case ANDROID_BOOT_MODE_BOOTLOADER:
>> + ret = boot_android_bootloader(bflow);
>> + break;
>> + default:
>> + printf("ANDROID: Unknown boot mode %d. Running fastboot...\n",
>> + priv->boot_mode);
>> + boot_android_bootloader(bflow);
>> + /* Tell we failed to boot since boot mode is unknown */
>> + ret = -EFAULT;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int android_bootmeth_bind(struct udevice *dev)
>> +{
>> + struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
>> +
>> + plat->desc = "Android boot";
>> + plat->flags = BOOTMETHF_ANY_PART;
>> +
>> + return 0;
>> +}
>> +
>> +static struct bootmeth_ops android_bootmeth_ops = {
>> + .check = android_check,
>> + .read_bootflow = android_read_bootflow,
>> + .read_file = android_read_file,
>> + .boot = android_boot,
>> +};
>> +
>> +static const struct udevice_id android_bootmeth_ids[] = {
>> + { .compatible = "u-boot,android" },
>> + { }
>> +};
>> +
>> +U_BOOT_DRIVER(bootmeth_android) = {
>> + .name = "bootmeth_android",
>> + .id = UCLASS_BOOTMETH,
>> + .of_match = android_bootmeth_ids,
>> + .ops = &android_bootmeth_ops,
>> + .bind = android_bootmeth_bind,
>> +};
>> diff --git a/boot/bootmeth_android.h b/boot/bootmeth_android.h
>> new file mode 100644
>> index 000000000000..411c2f2d15e7
>> --- /dev/null
>> +++ b/boot/bootmeth_android.h
>> @@ -0,0 +1,27 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * Bootmethod for Android
>> + *
>> + * Copyright (C) 2024 BayLibre, SAS
>> + * Written by Mattijs Korpershoek <mkorpershoek at baylibre.com>
>> + */
>> +
>> +enum android_boot_mode {
>> + ANDROID_BOOT_MODE_NORMAL = 0,
>> +
>> + /* Android "recovery" is a special boot mode that uses another ramdisk.
>> + * It can be used to "factory reset" a board or to flash logical partitions
>> + * It operates in 2 modes: adb or fastbootd
>> + * To enter recovery from Android, we can do:
>> + * $ adb reboot recovery
>> + * $ adb reboot fastboot
>> + */
>> + ANDROID_BOOT_MODE_RECOVERY,
>> +
>> + /* Android "bootloader" is for accessing/reflashing physical partitions
>> + * Typically, this will launch a fastboot process in U-Boot.
>> + * To enter "bootloader" from Android, we can do:
>> + * $ adb reboot bootloader
>> + */
>> + ANDROID_BOOT_MODE_BOOTLOADER,
>> +};
>> diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
>> index a07a72581e7a..709fa9e64ff3 100644
>> --- a/doc/develop/bootstd.rst
>> +++ b/doc/develop/bootstd.rst
>> @@ -95,6 +95,7 @@ bootflows.
>>
>> Note: it is possible to have a bootmeth that uses a partition or a whole device
>> directly, but it is more common to use a filesystem.
>> +For example, the Android bootmeth uses a whole device.
>>
>> Note that some bootmeths are 'global', meaning that they select the bootdev
>> themselves. Examples include VBE and EFI boot manager. In this case, they
>> @@ -277,6 +278,9 @@ script_offset_f
>> script_size_f
>> Size of the script to load, e.g. 0x2000
>>
>> +vendor_boot_comp_addr_r
>> + Address to which to load the vendor_boot Android image, e.g. 0xe0000000
>> +
>> Some variables are set by script bootmeth:
>>
>> devtype
>> @@ -418,6 +422,7 @@ Bootmeth drivers are provided for:
>> - EFI boot using bootefi from disk
>> - VBE
>> - EFI boot using boot manager
>> + - Android bootflow (boot image v4)
>>
>>
>> Command interface
>> @@ -786,6 +791,7 @@ To do
>> Some things that need to be done to completely replace the distro-boot scripts:
>>
>> - implement extensions (devicetree overlays with add-on boards)
>> +- implement legacy (boot image v2) android boot flow
>>
>> Other ideas:
>>
>>
>> --
>> 2.45.0
>>
>
> Some comments after a quick "scan". Will take a more detailed look a
> bit later today/tomorrow.
Thanks a bunch for your quick scan. You caught quite some issues
already.
I will implement these suggestions and will be awaiting the detailed
look before sending a v2.
> --
> Best regards - Atentamente - Meilleures salutations
>
> Igor Opaniuk
>
> mailto: igor.opaniuk at gmail.com
> skype: igor.opanyuk
> https://www.linkedin.com/in/iopaniuk
More information about the U-Boot
mailing list