From 183923d3e412500bdc597d1745e2fb6f7f679ec7 Mon Sep 17 00:00:00 2001 From: Andreas Fenkart Date: Thu, 11 Aug 2016 21:39:17 +0200 Subject: [PATCH] tools/env: ensure environment starts at erase block boundary 56086921 added support for unaligned environments access. U-boot itself does not support this: - env_nand.c fails when using an unaligned offset. It produces an error in nand_erase_opts{drivers/mtd/nand/nand_util.c} - in env_sf/env_flash the unused space at the end is preserved, but not in the beginning. block alignment is assumed - env_sata/env_mmc aligns offset/length to the block size of the underlying device. data is silently redirected to the beginning of a block There is seems no use case for unaligned environment. If there is some useful data at the beginning of the the block (e.g. end of u-boot) that would be very unsafe. If the redundant environments are hosted by the same erase block then that invalidates the idea of double buffering. It might be that unaligned access was allowed in the past, and that people with legacy u-boot are trapped. But at the time of 56086921 it wasn't supported and due to reasons above I guess it was never introduced. I prefer to remove that (unused) feature in favor of simplicity Signed-off-by: Andreas Fenkart Acked-by: Stefan Agner --- tools/env/fw_env.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c index 6b0dcaa943..d2b167deb9 100644 --- a/tools/env/fw_env.c +++ b/tools/env/fw_env.c @@ -1294,6 +1294,18 @@ static int check_device_config(int dev) struct stat st; int fd, rc = 0; + if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) { + fprintf(stderr, "Environment does not start on erase block boundary\n"); + errno = EINVAL; + return -1; + } + + if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) { + fprintf(stderr, "Environment does not fit into available sectors\n"); + errno = EINVAL; + return -1; + } + fd = open(DEVNAME(dev), O_RDONLY); if (fd < 0) { fprintf(stderr, -- 2.39.5