+Jocelyn.
Thanks Alex for taking the time to port this!! Some comments inline here about your questions.
2018-04-24 11:37 GMT+02:00 Alex Kiernan alex.kiernan@gmail.com:
This series merges the fastboot UDP support from AOSP into mainline U-Boot.
Open questions:
- what's the correct way of attributing the original authors? I've added Co-authored-by, is that right? checkpatch doesn't seem to know any of the co- tags
- currently there's no NAND support and I've no way of testing that, so my inclination is towards leaving it like that until someone with that particular itch to scratch can look at it
Fastboot uses partition names, like "system" and "boot" which have a meaning in the Android partition scheme. For GPT, we just use the partition names as the android names; but if you are booting from some other storage like NAND where you don't have that then you need some mapping glue ("system" --> device and partition number). I've seen U-Boot modifications for several devices where they just stick a table hard-coded in the U-Boot code; which works great for that device but it isn't really a generic approach. Other than handling the names issue, I don't see any problem with supporting NAND here, but a generic way to set global names / alias would be needed for this.
- you can select both USB and UDP fastboot, but the comments in the AOSP code suggest that needs fixing - again, I've no board I can test USB fastboot on
I thought we checked in the Kconfig that you couldn't enable both. I don't remember the details now but yeah you can't wait for network or USB traffic on the current code.
- the USB and UDP code want consolidating, with this series there would
then be two separate implementations of the same protocol
- the syntax for the USB fastboot command changes from `fastboot
<controller>` to `fastboot usb <controller>`, that feels unacceptable and we probably want something like `fastboot <controller>` or `fastboot udp`?
- unrelated to this series, but a show-stopper for me, there's no FIT image support, but that doesn't feel unsolveable - something like add an option to pass in the load address and/or use loadaddr, then something else to let you override the bootm invocation on the server side
I've not tested all the code paths yet, but the obvious stuff works (basic interaction, download, boot) - every interaction elicits a `WARNING: unknown variable: slot-count` on the console; I'm guessing that my local end is sending a getvar for that, but I've not investigated.
Yes, there's a bit of different handling of partitions for A/B android devices. Instead of "system" you have two partitions: "system_a" and "system_b" (potentially more although 2 is the most common case) so to know whether you have an old device or a newer device the fastboot client checks the "slot-count" variable. Undefined means of course that you have an old-style device, but if you return something like "2" you would be able to flash "system" on the "slot A" which is translated (again in the fastboot client) to flash "system_a" partition. This is useful when using the higher level operations like flashall/update and you want to specify to flash only "slot A", "slot B" or even both of them. There are other fastboot variables that require some plumbing, such as "has-slot:<partition>" to tell whether "system" is a partition that indeed has the two versions _a and _b. Typically some partitions are twice (like "system" and "boot") and some other are not (like "misc" or "userdata"). Anyway, this as is should work for either old-style partition schemes or by force flashing "system_a" with the system.img.
Without any way of testing any of the USB/NAND code I'm nervous of wading into that kind of refactoring, would that be a pre-requisite for merging?
Alex Kiernan (5): dfu: Refactor fastboot_okay/fail to take response dfu: Extract fastboot_okay/fail to fb_common.c net: dfu: Merge AOSP UDP fastboot dfu: Resolve Kconfig dependency loops net: dfu: Support building without MMC
cmd/fastboot.c | 32 ++- cmd/fastboot/Kconfig | 21 +- cmd/net.c | 6 + common/Makefile | 4 + common/fb_common.c | 44 ++++ common/fb_mmc.c | 114 ++++++--- common/fb_nand.c | 31 +-- common/image-sparse.c | 41 ++- drivers/usb/gadget/f_fastboot.c | 36 +-- include/fastboot.h | 17 +- include/fb_mmc.h | 4 +- include/fb_nand.h | 4 +- include/image-sparse.h | 2 +- include/net.h | 6 +- include/net/fastboot.h | 27 ++ net/Makefile | 1 + net/fastboot.c | 548 ++++++++++++++++++++++++++++++ ++++++++++ net/net.c | 9 + 18 files changed, 824 insertions(+), 123 deletions(-) create mode 100644 common/fb_common.c create mode 100644 include/net/fastboot.h create mode 100644 net/fastboot.c
-- 2.7.4