From f4742ca0fb94e531b8dcddd1ac0799ee4c9c2605 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Wed, 13 Jul 2016 17:14:38 -0700 Subject: [PATCH] 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 5c088ee841f9 ("env_mmc: allow negative CONFIG_ENV_OFFSET"). Signed-off-by: Stefan Agner --- tools/env/fw_env.c | 39 ++++++++++++++++++++++++++++++--------- tools/env/fw_env.config | 5 +++++ 2 files changed, 35 insertions(+), 9 deletions(-) diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c index 06d6865f3b..be338a5ba9 100644 --- a/tools/env/fw_env.c +++ b/tools/env/fw_env.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -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", - &devname, - &DEVOFFSET (i), - &ENVSIZE (i), - &DEVESIZE (i), - &ENVSECTORS (i)); + rc = sscanf(dump, "%ms %lli %lx %lx %lx", + &devname, + &DEVOFFSET(i), + &ENVSIZE(i), + &DEVESIZE(i), + &ENVSECTORS(i)); if (rc < 3) continue; diff --git a/tools/env/fw_env.config b/tools/env/fw_env.config index 776e16f784..7916ebdb1f 100644 --- a/tools/env/fw_env.config +++ b/tools/env/fw_env.config @@ -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 -- 2.39.5