When host fastboot sends sparse blocks to the device, it tries to only
send blocks in multiples of 1024 bytes. If a block is not aligned to this
size, the excess bytes are prepended to the next write operation. This
is implemented by doing the write in two steps: first the previous
excess from the last write (plus new data up to alignment), then a
second write for the aligned remainder of the new data.
This logic has a bug if the final block plus the previous excess data
contains >= 1024 but < 2048 bytes. In this case the first write will
drain 1024 bytes from the data, and the second write will not have 1024
bytes to write. Instead of retaining this data for the next write, it
tries to write 0 chunks (and thus 0 bytes), which hangs the ioctl() call.
Bug: N/A
Test: "fastboot flash super super.img" where super.img is generated by
lpmake, containing system and product_services partitions and
images.
Change-Id: I9e8523c976ec84d5a57b36a28f4b1ca800edb7e7
This change creates a nice and clean API for issuing
fastboot commands without using the fastboot tool itself.
Test: fastboot tool itself (now using libfastboot2)
on sailfish, walleye, and other devices.
Test: flash bootloader bootloader.img
Test: flash radio radio.img
Test: -w update img.zip
Test: Manually getvar and reboot commands.
Bug: 111126621
Change-Id: I0022536b204ce0c5ad8329367fd522fa3c57877d
David Anderson