From 64a11fb8c9a1a5ae385043e5f5e197fa213cc702 Mon Sep 17 00:00:00 2001 From: Mattijs Korpershoek Date: Thu, 13 Oct 2022 14:25:59 +0200 Subject: [PATCH] cmd: bcb: select user(0) hwpart in __bcb_load() For some blk operations, it's possible that a different hw partition gets selected via blk_dselect_hwpart(). In that case, only the region of the device covered by that partition is accessible. This breaks "bcb load" which attempts to read the gpt and assumes it's on the user(0) hw partition: => bcb load 2 misc GUID Partition Table Header signature is wrong: 0xDE7B17AD07D9E5D6 != 0x5452415020494645 find_valid_gpt: *** ERROR: Invalid GPT *** GUID Partition Table Header signature is wrong: 0x0 != 0x5452415020494645 find_valid_gpt: *** ERROR: Invalid Backup GPT *** Error: mmc 2:misc read failed (-2) Add a fail-safe in __bcb_load() to ensure we will always read from the user(0) hwpartition. This fixes the following fastboot sequence: $ fastboot erase mmc2boot1 # switch to hwpart1 $ fastboot reboot bootloader # switch to hwpart0, then reads GPT Signed-off-by: Mattijs Korpershoek Reviewed-by: Sean Anderson --- cmd/bcb.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/cmd/bcb.c b/cmd/bcb.c index 1622a90..02d0c70 100644 --- a/cmd/bcb.c +++ b/cmd/bcb.c @@ -14,6 +14,7 @@ #include #include #include +#include enum bcb_cmd { BCB_CMD_LOAD, @@ -128,6 +129,16 @@ static int __bcb_load(int devnum, const char *partp) goto err_read_fail; } + /* + * always select the USER mmc hwpart in case another + * blk operation selected a different hwpart + */ + ret = blk_dselect_hwpart(desc, 0); + if (IS_ERR_VALUE(ret)) { + ret = -ENODEV; + goto err_read_fail; + } + part = simple_strtoul(partp, &endp, 0); if (*endp == '\0') { ret = part_get_info(desc, part, &info); -- 2.7.4