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 <andreas.fenkart@digitalstrom.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index 6b0dcaa..d2b167d 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1294,6 +1294,18 @@
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,