From 730148bc94411f13a0171204e872b0760fbde185 Mon Sep 17 00:00:00 2001 From: Brandon Maier Date: Mon, 12 Dec 2022 12:01:58 -0600 Subject: mtd-utils: Add new syntax to get devices by name This introduces a new feature to the MTD command line utilities that allows MTD devices to be referenced by name instead of device node. For example this looks like: > # Display info for the MTD device with name "data" > mtdinfo mtd:data > # Copy file to MTD device with name "data" > flashcp /my/file mtd:data This follows the syntax supported by the kernel which allows MTD device's to be mounted by name[1]. Add the function mtd_find_dev_node() that accepts an MTD "identifier" and returns the MTD's device node. The function accepts a string starting with "mtd:" which it treats as the MTD's name. It then attempts to search for the MTD, and if found maps it back to the /dev/mtdX device node. If the string does not start with "mtd:", then assume it's the old style and refers directly to a MTD device node. The function is then hooked into existing tools like flashcp, mtdinfo, flash_unlock, etc. To load in the new MTD parsing code in a consistent way across programs. [1] http://www.linux-mtd.infradead.org/faq/jffs2.html#L_mtdblock Signed-off-by: Brandon Maier Signed-off-by: David Oberhollenzer --- lib/common.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'lib') diff --git a/lib/common.c b/lib/common.c index 8041878..e278593 100644 --- a/lib/common.c +++ b/lib/common.c @@ -33,6 +33,9 @@ #include #include #include "common.h" +#include "libmtd.h" + +#define MTD_DEV_PATT "/dev/mtd%d" /** * get_multiplier - convert size specifier to an integer multiplier. @@ -162,3 +165,46 @@ int util_srand(void) srand(seed); return 0; } + +/** + * mtd_find_dev_node - Find the device node for an MTD + * @id: Identifier for the MTD. this can be the device node itself, or + * "mtd:" to look up MTD by name + * + * This is a helper function to convert MTD device identifiers into their + * device node. + * + * Returns a pointer to a string containing the device node that must be + * free'd, or NULL on failure. + */ +char *mtd_find_dev_node(const char *id) +{ + struct mtd_dev_info info; + struct libmtd_t *lib_mtd; + char *node; + int ret; + + if (strncmp(id, "mtd:", 4)) { + /* Assume @id is the device node */ + return strdup(id); + } + + /* Search for MTD matching name */ + id += 4; + + lib_mtd = libmtd_open(); + if (!lib_mtd) + return NULL; + + ret = mtd_get_dev_info2(lib_mtd, id, &info); + libmtd_close(lib_mtd); + if (ret < 0) + return NULL; + + node = malloc(strlen(MTD_DEV_PATT) + 20); + if (!node) + return NULL; + + sprintf(node, MTD_DEV_PATT, info.mtd_num); + return node; +} -- cgit v1.2.3