Hi Eugeniu,
On Thu, Jun 13, 2019 at 12:31 PM Eugeniu Rosca erosca@de.adit-jv.com wrote:
Hi Sam,
On Thu, Jun 13, 2019 at 12:49:45AM +0300, Sam Protsenko wrote:
In commit [1] fastboot tool was changed w.r.t. new A/B specification [2], and now we should report slot names in "a" format instead of "_a". Latter is now considered legacy and we shouldn't rely on that anymore.
This looks like a change which advantages the users who are always on the tip/HEAD of all relevant components (fastboot and U-Boot), but that rarely happens in the industry. Suppliers and hardening vendors often deliver obsoleted versions because they can't keep up with upstream development. Can you please document the behavior of 'fastboot flash' (and anything else relying on 'fastboot getvar (current-slot|slot-suffixes) in below scenarios:
A. fastboot >= [1] && U-Boot + this patch B. fastboot >= [1] && U-Boot - this patch C. fastboot < [1] && U-Boot + this patch D. fastboot < [1] && U-Boot - this patch
Would it be possible to keep U-Boot backward-compatible, such that regardless of the scenario enumerated above, 'fastboot flash' will always succeed?
I'm afraid in this particular case we weren't given any choice, and we won't be able to provide backward-compatibility for older Android releases. After this commit:
[3] https://android.googlesource.com/platform/system/core/+/42b18a518bac85c3eea1...
they dropped support for "_a" format completely (in fastboot tool). So: * if user runs new fastboot tool ( >= [3]), then the only way to make "fastboot flash" work is to return slot in "a" format from bootloader * if user runs old fastboot tool (< [1]), then the only way to make "fastboot flash" work is to return slot in "_a" format from bootloader
Good news is that user can basically downgrade or upgrade fastboot tool, to be in sync with U-Boot version in use. Bad news, we need to decide which Android version to break in U-Boot/master.
I suggest we track AOSP/master in U-Boot/master. Please let me know if you agree, or maybe there is some better way I'm missing.
Thanks!
[1] https://android.googlesource.com/platform/system/core/+/8091947847d5e5130b09... [2] https://source.android.com/devices/tech/ota/ab/ab_implement#partitions
-- Best Regards, Eugeniu.