| Message ID | 20220616185903.14426-1-zajec5@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | fw_env: add fallback to Linux's NVMEM based access | expand |
On Thu, Jun 16, 2022 at 08:59:03PM +0200, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > A new DT binding for describing environment data block has been added in > Linux's commit 5db1c2dbc04c ("dt-bindings: nvmem: add U-Boot environment > variables binding"). Once we get a proper Linux NVMEM driver it'll be > possible to use Linux's binary interface for user-space as documented > in the: > https://www.kernel.org/doc/html/latest/driver-api/nvmem.html > > This commits makes fw_env fallback to looking for a compatible NVMEM > device in case config file isn't present. In a long term this may make > config files redundant and avoid code (info) duplication. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Applied to u-boot/next, thanks!
On 16.06.2022 21:59, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > A new DT binding for describing environment data block has been added in > Linux's commit 5db1c2dbc04c ("dt-bindings: nvmem: add U-Boot environment > variables binding"). Once we get a proper Linux NVMEM driver it'll be > possible to use Linux's binary interface for user-space as documented > in the: > https://www.kernel.org/doc/html/latest/driver-api/nvmem.html > > This commits makes fw_env fallback to looking for a compatible NVMEM > device in case config file isn't present. In a long term this may make > config files redundant and avoid code (info) duplication. > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> I see the Linux NVMEM driver [0] does not implement @reg_write. Does this mean only fw_printenv would work for this method? [0] https://github.com/torvalds/linux/blob/c49f1a8af6bcf6d18576bca898f8083ca4b129e1/drivers/nvmem/u-boot-env.c Arınç
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c index 31afef6f3b..be77bbf054 100644 --- a/tools/env/fw_env.c +++ b/tools/env/fw_env.c @@ -1713,6 +1713,67 @@ static int check_device_config(int dev) return rc; } +static int find_nvmem_device(void) +{ + const char *path = "/sys/bus/nvmem/devices"; + struct dirent *dent; + char *nvmem = NULL; + char comp[256]; + char buf[32]; + int bytes; + DIR *dir; + + dir = opendir(path); + if (!dir) { + return -EIO; + } + + while (!nvmem && (dent = readdir(dir))) { + FILE *fp; + + if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, "..")) { + continue; + } + + bytes = snprintf(comp, sizeof(comp), "%s/%s/of_node/compatible", path, dent->d_name); + if (bytes < 0 || bytes == sizeof(comp)) { + continue; + } + + fp = fopen(comp, "r"); + if (!fp) { + continue; + } + + fread(buf, sizeof(buf), 1, fp); + + if (!strcmp(buf, "u-boot,env")) { + bytes = asprintf(&nvmem, "%s/%s/nvmem", path, dent->d_name); + if (bytes < 0) { + nvmem = NULL; + } + } + + fclose(fp); + } + + closedir(dir); + + if (nvmem) { + struct stat s; + + stat(nvmem, &s); + + DEVNAME(0) = nvmem; + DEVOFFSET(0) = 0; + ENVSIZE(0) = s.st_size; + + return 0; + } + + return -ENOENT; +} + static int parse_config(struct env_opts *opts) { int rc; @@ -1723,9 +1784,12 @@ static int parse_config(struct env_opts *opts) #if defined(CONFIG_FILE) /* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */ if (get_config(opts->config_file)) { - fprintf(stderr, "Cannot parse config file '%s': %m\n", - opts->config_file); - return -1; + if (find_nvmem_device()) { + fprintf(stderr, "Cannot parse config file '%s': %m\n", + opts->config_file); + fprintf(stderr, "Failed to find NVMEM device\n"); + return -1; + } } #else DEVNAME(0) = DEVICE1_NAME;