Hi Dmitry,
Thank you for the patch.
Hi Simon,
On dim., juil. 28, 2024 at 13:36, Simon Glass <s...@chromium.org> wrote:
> Hi Dmitry,
>
> On Thu, 25 Jul 2024 at 14:55, Dmitry Rokosov
> <ddroko...@salutedevices.com> wrote:
>>
>> It's really helpful to have the ability to dump BCB block for debugging
>> A/B logic on the board supported this partition schema.
>>
>> Command 'ab_dump' prints all fields of bootloader_control struct
>> including slot_metadata for all presented slots.
>>
>> Output example:
>> =====
>> > board# ab_dump ubi 0#misc
>> > Read 512 bytes from volume misc to 000000000bf51900
>> > Bootloader Control: [misc]
>> > Active Slot: _a
>> > Magic Number: 0x42414342
>> > Version: 1
>> > Number of Slots: 2
>> > Recovery Tries Remaining: 7
>> > CRC: 0x61378F6F (Valid)
>> >
>> > Slot[0] Metadata:
>> > - Priority: 15
>> > - Tries Remaining: 4
>> > - Successful Boot: 0
>> > - Verity Corrupted: 0
>> >
>> > Slot[1] Metadata:
>> > - Priority: 15
>> > - Tries Remaining: 5
>> > - Successful Boot: 0
>> > - Verity Corrupted: 0
>> ====
>>
>> Signed-off-by: Dmitry Rokosov <ddroko...@salutedevices.com>
>> ---
>> boot/android_ab.c | 68 ++++++++++++++++++++++++++++++++++++++++++++
>> cmd/ab_select.c | 30 +++++++++++++++++++
>> include/android_ab.h | 9 ++++++
>> 3 files changed, 107 insertions(+)
>>
>> diff --git a/boot/android_ab.c b/boot/android_ab.c
>> index 1e5aa81b7503..359cc1a00428 100644
>> --- a/boot/android_ab.c
>> +++ b/boot/android_ab.c
>> @@ -363,3 +363,71 @@ int ab_select_slot(struct blk_desc *dev_desc, struct
>> disk_partition *part_info,
>>
>> return slot;
>> }
>> +
>> +int ab_dump_abc(struct blk_desc *dev_desc, struct disk_partition *part_info)
>> +{
>> + struct bootloader_control *abc;
>> + u32 crc32_le;
>> + int i, ret;
>> + struct slot_metadata *slot;
>> +
>> + if (!dev_desc || !part_info) {
>> + log_err("ANDROID: Empty device descriptor or partition
>> info\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = ab_control_create_from_disk(dev_desc, part_info, &abc, 0);
>> + if (ret < 0) {
>> + log_err("ANDROID: Cannot create bcb from disk %d\n", ret);
>> + return ret;
>> + }
>> +
>> + if (abc->magic != BOOT_CTRL_MAGIC) {
>> + log_err("ANDROID: Unknown A/B metadata: %.8x\n", abc->magic);
>> + ret = -ENODATA;
>> + goto error;
>> + }
>> +
>> + if (abc->version > BOOT_CTRL_VERSION) {
>> + log_err("ANDROID: Unsupported A/B metadata version: %.8x\n",
>> + abc->version);
>> + ret = -ENODATA;
>> + goto error;
>> + }
>> +
>> + if (abc->nb_slot > ARRAY_SIZE(abc->slot_info)) {
>> + log_err("ANDROID: Wrong number of slots %u, expected %zu\n",
>> + abc->nb_slot, ARRAY_SIZE(abc->slot_info));
>> + ret = -ENODATA;
>> + goto error;
>> + }
>> +
>> + printf("Bootloader Control: \t[%s]\n", part_info->name);
>> + printf("Active Slot: \t\t%s\n", abc->slot_suffix);
>> + printf("Magic Number: \t\t0x%X\n", abc->magic);
>> + printf("Version: \t\t%u\n", abc->version);
>> + printf("Number of Slots: \t%u\n", abc->nb_slot);
>> + printf("Recovery Tries Remaining: %u\n",
>> abc->recovery_tries_remaining);
In the console, this rendered not perfectly aligned, which is a bit of a
shame:
(done on sandbox)
=> ab_dump mmc 7#misc
Bootloader Control: [misc]
Active Slot: _a
Magic Number: 0x42414342
Version: 1
Number of Slots: 2
Recovery Tries Remaining: 0
CRC: 0x321FEF27 (Valid)
>> +
>> + printf("CRC: \t\t\t0x%.8X", abc->crc32_le);
>> +
>> + crc32_le = ab_control_compute_crc(abc);
>> + if (abc->crc32_le != crc32_le)
>> + printf(" (Invalid, Expected: \t0x%.8X)\n", crc32_le);
>> + else
>> + printf(" (Valid)\n");
>> +
>> + for (i = 0; i < abc->nb_slot; ++i) {
>> + slot = &abc->slot_info[i];
>> + printf("\nSlot[%d] Metadata:\n", i);
>> + printf("\t- Priority: \t\t%u\n", slot->priority);
>> + printf("\t- Tries Remaining: \t%u\n", slot->tries_remaining);
>> + printf("\t- Successful Boot: \t%u\n", slot->successful_boot);
>> + printf("\t- Verity Corrupted: \t%u\n",
>> slot->verity_corrupted);
>> + }
>> +
>> +error:
>> + free(abc);
>> +
>> + return ret;
>> +}
>> diff --git a/cmd/ab_select.c b/cmd/ab_select.c
>> index 9e2f74573c22..1d34150ceea9 100644
>> --- a/cmd/ab_select.c
>> +++ b/cmd/ab_select.c
>> @@ -51,6 +51,31 @@ static int do_ab_select(struct cmd_tbl *cmdtp, int flag,
>> int argc,
>> return CMD_RET_SUCCESS;
>> }
>>
>> +static int do_ab_dump(struct cmd_tbl *cmdtp, int flag, int argc,
>> + char *const argv[])
>> +{
>> + int ret;
>> + struct blk_desc *dev_desc;
>> + struct disk_partition part_info;
>> +
>> + if (argc < 3)
>> + return CMD_RET_USAGE;
>> +
>> + if (part_get_info_by_dev_and_name_or_num(argv[1], argv[2],
>> + &dev_desc, &part_info,
>> + false) < 0) {
>> + return CMD_RET_FAILURE;
>> + }
>> +
>> + ret = ab_dump_abc(dev_desc, &part_info);
>> + if (ret < 0) {
>> + printf("Cannot dump ABC data, error %d.\n", ret);
>> + return CMD_RET_FAILURE;
>> + }
>> +
>> + return CMD_RET_SUCCESS;
>> +}
>> +
>> U_BOOT_CMD(ab_select, 5, 0, do_ab_select,
>> "Select the slot used to boot from and register the boot
>> attempt.",
>> "<slot_var_name> <interface> <dev[:part|#part_name]> [--no-dec]\n"
>> @@ -66,3 +91,8 @@ U_BOOT_CMD(ab_select, 5, 0, do_ab_select,
>> " - If '--no-dec' is set, the number of tries remaining will
>> not\n"
>> " decremented for the selected boot slot\n"
>> );
>> +
>> +U_BOOT_CMD(ab_dump, 3, 0, do_ab_dump,
>> + "Dump boot_control information from specific partition.",
>> + "<interface> <dev[:part|#part_name]>\n"
>> +);
>> diff --git a/include/android_ab.h b/include/android_ab.h
>> index 1fee7582b90a..e53bf7eb6a02 100644
>> --- a/include/android_ab.h
>> +++ b/include/android_ab.h
>> @@ -33,4 +33,13 @@ struct disk_partition;
>> int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition
>> *part_info,
>> bool dec_tries);
>>
>> +/**
>> + * Dump ABC information for specific partition.
>> + *
>> + * @param[in] dev_desc Device description pointer
>> + * @param[in] part_info Partition information
>
> We have moved to the @ notation now:
>
> @dev_desc: ...
I agree with this comment, but the file uses @param[in] already. We
should to a preparatory patch to convert this file to the new notation.
>
>> + * Return: 0 on success, or a negative on error
>> + */
>> +int ab_dump_abc(struct blk_desc *dev_desc, struct disk_partition
>> *part_info);
>> +
>> #endif /* __ANDROID_AB_H */
>> --
>> 2.43.0
>>
>
> Rather than creating a new command I think this should be a subcommand
> of abootimg.
To me, they are not the same thing.
- ab_* commands are for manipulating specific bits from the BCB (Boot
Control Block, usually "misc" partition)
ab_* operates on partitions
- abootimg is for manipulating boot.img and vendor_boot.img headers
(which are not on the same partitions)
abootimg operations on memory regions (so someone else is responsible
for reading the partitions)
We also have a 3rd command "bcb". "bcb" also reads the "misc" partition
but can only read the "boot reason".
If we really want to merge ab_select and ab_dump into another command,
"bcb" is more relevant, in my opinion.
I'd prefer to keep 3 commands for the following reasons:
1. Easier to track/port changes from Google's fork [1]
2. Better separation of responsabilities
3. Merging the commands requires the update of the existing U-Boot
environment users (meson64_android.h for example)
I don't strongly disagree with merging, but I'd prefer to keep it this way.
[1] https://android.googlesource.com/platform/external/u-boot
Simon, can you elaborate on why we should merge the commands? Do you
think that for U-Boot users it will be easier to have a single command
for all Android related topics?
>
> Can you please create some docs in doc/usage/cmd/abootimg for the command?
>
> I also wonder if ab_select should move under that command?
>
> Regards,
> SImon
