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https://github.com/AsahiLinux/u-boot
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e282c422e0
We have a board with several revisions. The older ones use a nor flash with 64k erase size, while the newer have a flash with 4k sectors. The environment size is 8k. Currently, we have to put a column containing 0x10000 (64k) in fw_env.config in order for it to work on the older boards. But that ends up wasting quite a lot of time on the newer boards that could just erase the 8k occupied by the environment - strace says the 64k erase takes 0.405 seconds. With this patch, as expected, that's about an 8-fold better, at 0.043 seconds. Having different fw_env.config files for the different revisions is highly impractical, and the correct information is already available right at our fingertips. So use the erasesize returned by the MEMGETINFO ioctl when the fourth and fifth columns (sector size and #sectors, respectively) are absent or contain 0, a case where the logic previously used to use the environment size as erase size (and consequently computed ENVSECTORS(dev) as 1). As I'm only testing this on a NOR flash, I'm only changing the logic for that case, though I think it should be possible for the other types as well. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> |
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| .. | ||
| .gitignore | ||
| crc32.c | ||
| ctype.c | ||
| env_attr.c | ||
| env_flags.c | ||
| fw_env.c | ||
| fw_env.config | ||
| fw_env.h | ||
| fw_env_main.c | ||
| fw_env_private.h | ||
| linux_string.c | ||
| Makefile | ||
| README | ||
This is a demo implementation of a Linux command line tool to access
the U-Boot's environment variables.
In order to cross-compile fw_printenv, run
make CROSS_COMPILE=<your cross-compiler prefix> envtools
in the root directory of the U-Boot distribution. For example,
make CROSS_COMPILE=arm-linux- envtools
You should then create a symlink from fw_setenv to fw_printenv. They use
the same program and its function depends on its basename.
For the run-time utility configuration uncomment the line
#define CONFIG_FILE "/etc/fw_env.config"
in fw_env.h.
For building against older versions of the MTD headers (meaning before
v2.6.8-rc1) it is required to pass the argument "MTD_VERSION=old" to
make.
See comments in the fw_env.config file for definitions for the
particular board.
Configuration can also be done via #defines in the fw_env.h file. The
following lines are relevant:
#define HAVE_REDUND /* For systems with 2 env sectors */
#define DEVICE1_NAME "/dev/mtd1"
#define DEVICE2_NAME "/dev/mtd2"
#define DEVICE1_OFFSET 0x0000
#define ENV1_SIZE 0x4000
#define DEVICE1_ESIZE 0x4000
#define DEVICE1_ENVSECTORS 2
#define DEVICE2_OFFSET 0x0000
#define ENV2_SIZE 0x4000
#define DEVICE2_ESIZE 0x4000
#define DEVICE2_ENVSECTORS 2
Un-define HAVE_REDUND, if you want to use the utilities on a system
that does not have support for redundant environment enabled.
If HAVE_REDUND is undefined, DEVICE2_NAME is ignored,
as is ENV2_SIZE and DEVICE2_ESIZE.
The DEVICEx_NAME constants define which MTD character devices are to
be used to access the environment.
The DEVICEx_OFFSET constants define the environment offset within the
MTD character device.
ENVx_SIZE defines the size in bytes taken by the environment, which
may be less then flash sector size, if the environment takes less
then 1 sector.
DEVICEx_ESIZE defines the size of the first sector in the flash
partition where the environment resides.
DEVICEx_ENVSECTORS defines the number of sectors that may be used for
this environment instance. On NAND this is used to limit the range
within which bad blocks are skipped, on NOR it is not used.
To prevent losing changes to the environment and to prevent confusing the MTD
drivers, a lock file at /var/lock/fw_printenv.lock is used to serialize access
to the environment.