tools/env: allow negative offsets

A negative value for the offset is treated as a backwards offset for
from the end of the device/partition for block devices. This aligns
the behavior of the config file with the syntax of CONFIG_ENV_OFFSET
where the functionality has been introduced with
commit 5c088ee841 ("env_mmc: allow negative CONFIG_ENV_OFFSET").

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
This commit is contained in:
Stefan Agner 2016-07-13 17:14:38 -07:00 committed by Tom Rini
parent 14fb5b252a
commit f4742ca0fb
2 changed files with 35 additions and 9 deletions

37
tools/env/fw_env.c vendored
View file

@ -14,6 +14,7 @@
#include <errno.h>
#include <env_flags.h>
#include <fcntl.h>
#include <linux/fs.h>
#include <linux/stringify.h>
#include <ctype.h>
#include <stdio.h>
@ -51,7 +52,7 @@ struct env_opts default_opts = {
struct envdev_s {
const char *devname; /* Device name */
ulong devoff; /* Device offset */
long long devoff; /* Device offset */
ulong env_size; /* environment size */
ulong erase_size; /* device erase size */
ulong env_sectors; /* number of environment sectors */
@ -994,7 +995,7 @@ static int flash_write (int fd_current, int fd_target, int dev_target)
}
#ifdef DEBUG
fprintf(stderr, "Writing new environment at 0x%lx on %s\n",
fprintf(stderr, "Writing new environment at 0x%llx on %s\n",
DEVOFFSET (dev_target), DEVNAME (dev_target));
#endif
@ -1010,7 +1011,7 @@ static int flash_write (int fd_current, int fd_target, int dev_target)
offsetof (struct env_image_redundant, flags);
#ifdef DEBUG
fprintf(stderr,
"Setting obsolete flag in environment at 0x%lx on %s\n",
"Setting obsolete flag in environment at 0x%llx on %s\n",
DEVOFFSET (dev_current), DEVNAME (dev_current));
#endif
flash_flag_obsolete (dev_current, fd_current, offset);
@ -1335,7 +1336,27 @@ static int check_device_config(int dev)
}
DEVTYPE(dev) = mtdinfo.type;
} else {
uint64_t size;
DEVTYPE(dev) = MTD_ABSENT;
/*
* Check for negative offsets, treat it as backwards offset
* from the end of the block device
*/
if (DEVOFFSET(dev) < 0) {
rc = ioctl(fd, BLKGETSIZE64, &size);
if (rc < 0) {
fprintf(stderr, "Could not get block device size on %s\n",
DEVNAME(dev));
goto err;
}
DEVOFFSET(dev) = DEVOFFSET(dev) + size;
#ifdef DEBUG
fprintf(stderr, "Calculated device offset 0x%llx on %s\n",
DEVOFFSET(dev), DEVNAME(dev));
#endif
}
}
err:
@ -1434,12 +1455,12 @@ static int get_config (char *fname)
if (dump[0] == '#')
continue;
rc = sscanf (dump, "%ms %lx %lx %lx %lx",
rc = sscanf(dump, "%ms %lli %lx %lx %lx",
&devname,
&DEVOFFSET (i),
&ENVSIZE (i),
&DEVESIZE (i),
&ENVSECTORS (i));
&DEVOFFSET(i),
&ENVSIZE(i),
&DEVESIZE(i),
&ENVSECTORS(i));
if (rc < 3)
continue;

View file

@ -4,6 +4,7 @@
# Notice, that the "Number of sectors" is not required on NOR and SPI-dataflash.
# Futhermore, if the Flash sector size is omitted, this value is assumed to
# be the same as the Environment size, which is valid for NOR and SPI-dataflash
# Device offset must be prefixed with 0x to be parsed as a hexadecimal value.
# NOR example
# MTD device name Device offset Env. size Flash sector size Number of sectors
@ -18,8 +19,12 @@
# NAND example
#/dev/mtd0 0x4000 0x4000 0x20000 2
# On a block device a negative offset is treated as a backwards offset from the
# end of the device/partition, rather than a forwards offset from the start.
# Block device example
#/dev/mmcblk0 0xc0000 0x20000
#/dev/mmcblk0 -0x20000 0x20000
# VFAT example
#/boot/uboot.env 0x0000 0x4000