From: Alison Chaiken <ali...@peloton-tech.com> One way for userspace and the bootloader to exchange information about dynamic image selection is via the storage device partition table, as described at
https://source.android.com/devices/tech/ota/ab_updates The scheme described there relies on setting partitions' "boot" flag. When no partition on a device is bootable since the kernel and U-Boot are stored elsewhere, the name field in the GPT partition table offers another logical place to store information. These patches allow users to easily modify GPT partition names via bootscripts that can select different images based on a boot-failure counter, or when userspace installs a software update. These patches have been tested in the u-boot sandbox and (re)tested on a TI DRA7xx-based SOM with U-Boot 2015.07. Significant changes since v3: -- Testing in sandbox showed error in NULL termination of UUID string in cmd/gpt.c. That problem is fixed in 0001-GPT-read-partition-table-from-device-into-a-data-str.patch. -- Patch 3 "GPT: fix error in partitions string doc" now only treats the topic in the commit title, as the part dealing with the proposed 'flip' feature is moved to that patch. -- Two new commits come from testing in the sandbox (of which I was previously unaware). One fixes an error in README.sandbox, and one adds a few comments about sandbox testing to README.gpt. Significant changes since v2: -- Got rid of the need to allocate memory for the GUID string in do_gpt(); -- Fixed the problems with string NULL termination in allocate_disk_part(); -- Removed duplicate definition of MAX_SEARCH_PARTITIONS from disk/part.c and increased the value in include/part.h to 64; -- Improved the commit message for "rename GPT partitions to detect boot failure" to better describe the version of the patch I submitted; -- Fixed numerous small problems with function return values. Significant changes since v1: -- Put the gpt_flip() function and auxiliary ones inside a new CONFIG_CMD_GPT_FLIP option that depends on CMD_GPT. -- Replace intentional overwriting of name and type string arrays with memset() instead. -- Move part.h changes earlier in the patchset. -- Add a few lines to README.gpt about the new gpt subcommands. Added a few simple patches to do the following: -- Replace remaining occurrences of '37' with UUID_STR_LEN+1; -- Introduce new macros to get rid of the similar '32'; -- fix a smaller error in doc/README.gpt. There are also some fixups of whitespace and formatting errors (plus usual inevitable addition of new ones). To do in future: -- Add support for preserving the type flag for partitions. The u-boot version on which this patchset is based did not have this feature, and it's easy to add, but I need to figure how to test it first. -- Add tests for the new gpt commands to the sandbox. Alison Chaiken (5): GPT: read partition table from device into a data structure rename GPT partitions to detect boot failure GPT: fix error in partitions string doc sandbox: README: fix partition command invocation cmd gpt: test in sandbox board/sandbox/README.sandbox | 2 +- cmd/Kconfig | 7 + cmd/gpt.c | 298 +++++++++++++++++++++++++++++++++++++++++++ doc/README.gpt | 31 ++++- include/part.h | 7 + 5 files changed, 340 insertions(+), 5 deletions(-) -- 2.1.4 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
