ubi-utils: add libmtd

Just collection of functions to make it easier to work with MTD devices.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 314 insertions, 0 deletions

diff --git a/ubi-utils/new-utils/src/libmtd.c b/ubi-utils/new-utils/src/libmtd.c
new file mode 100644
index 0000000..aab4b0e
--- /dev/null
+++ b/ubi-utils/new-utils/src/libmtd.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Author: Artem Bityutskiy
+ *
+ * MTD library.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <mtd/mtd-user.h>
+#include <libmtd.h>
+#include "common.h"
+
+#define PROGRAM_NAME "libmtd"
+#define MTD_DEV_MAJOR 90
+
+/**
+ * mtd_get_info - get information about an MTD device.
+ * @node: name of the MTD device node
+ * @mtd: the MTD device information is returned here
+ *
+ * This function gets information about MTD device defined by the @node device
+ * node file and saves this information in the @mtd object. Returns %0 in case
+ * of success and %-1 in case of failure.
+ */
+int mtd_get_info(const char *node, struct mtd_info *mtd)
+{
+	struct stat st;
+	struct mtd_info_user ui;
+	int ret;
+	loff_t offs = 0;
+
+	if (stat(node, &st))
+		return sys_errmsg("cannot open \"%s\"", node);
+
+	if (!S_ISCHR(st.st_mode)) {
+		errno = EINVAL;
+		return errmsg("\"%s\" is not a character device", node);
+	}
+
+	mtd->major = major(st.st_rdev);
+	mtd->minor = minor(st.st_rdev);
+
+	if (mtd->major != MTD_DEV_MAJOR) {
+		errno = EINVAL;
+		return errmsg("\"%s\" has major number %d, MTD devices have "
+			      "major %d", node, mtd->major, MTD_DEV_MAJOR);
+	}
+
+	mtd->num = mtd->minor / 2;
+	mtd->rdonly = mtd->minor & 1;
+
+	mtd->fd = open(node, O_RDWR);
+	if (mtd->fd == -1)
+		return sys_errmsg("cannot open \"%s\"", node);
+
+	if (ioctl(mtd->fd, MEMGETINFO, &ui)) {
+		sys_errmsg("MEMGETINFO ioctl request failed");
+		goto out_close;
+	}
+
+	ret = ioctl(mtd->fd, MEMGETBADBLOCK, &offs);
+	if (ret == -1) {
+		if (errno != EOPNOTSUPP) {
+			sys_errmsg("MEMGETBADBLOCK ioctl failed");
+			goto out_close;
+		}
+		errno = 0;
+		mtd->allows_bb = 0;
+	} else
+		mtd->allows_bb = 1;
+
+	mtd->type = ui.type;
+	mtd->size = ui.size;
+	mtd->eb_size = ui.erasesize;
+	mtd->min_io_size = ui.writesize;
+
+	if (mtd->min_io_size <= 0) {
+		errmsg("mtd%d (%s) has insane min. I/O unit size %d",
+		       mtd->num, node, mtd->min_io_size);
+		goto out_close;
+	}
+	if (mtd->eb_size <= 0 || mtd->eb_size < mtd->min_io_size) {
+		errmsg("mtd%d (%s) has insane eraseblock size %d",
+		       mtd->num, node, mtd->eb_size);
+		goto out_close;
+	}
+	if (mtd->size <= 0 || mtd->size < mtd->eb_size) {
+		errmsg("mtd%d (%s) has insane size %lld",
+		       mtd->num, node, mtd->size);
+		goto out_close;
+	}
+	mtd->eb_cnt = mtd->size / mtd->eb_size;
+
+	switch(mtd->type) {
+	case MTD_ABSENT:
+		errmsg("mtd%d (%s) is removable and is not present",
+		       mtd->num, node);
+		goto out_close;
+	case MTD_RAM:
+		mtd->type_str = "RAM-based";
+		break;
+	case MTD_ROM:
+		mtd->type_str = "ROM";
+		break;
+	case MTD_NORFLASH:
+		mtd->type_str = "NOR";
+		break;
+	case MTD_NANDFLASH:
+		mtd->type_str = "NAND";
+		break;
+	case MTD_DATAFLASH:
+		mtd->type_str = "DataFlash";
+		break;
+	case MTD_UBIVOLUME:
+		mtd->type_str = "UBI-emulated MTD";
+		break;
+	default:
+		mtd->type_str = "Unknown flash type";
+		break;
+	}
+
+	if (!(ui.flags & MTD_WRITEABLE))
+		mtd->rdonly = 1;
+
+	return 0;
+
+out_close:
+	close(mtd->fd);
+	return -1;
+}
+
+/**
+ * mtd_erase - erase an eraseblock.
+ * @mtd: MTD device description object
+ * @eb: eraseblock to erase
+ *
+ * This function erases the eraseblock and returns %0 in case of success and
+ * %-1 in case of failure.
+ */
+int mtd_erase(const struct mtd_info *mtd, int eb)
+{
+	struct erase_info_user ei;
+
+	ei.start = eb * mtd->eb_size;;
+	ei.length = mtd->eb_size;
+	return ioctl(mtd->fd, MEMERASE, &ei);
+}
+
+/**
+ * mtd_is_bad - check if eraseblock is bad.
+ * @mtd: MTD device description object
+ * @eb: eraseblock to check
+ *
+ * This function checks if eraseblock @eb is bad. Returns %0 if not, %1 if yes,
+ * and %-1 in case of failure.
+ */
+int mtd_is_bad(const struct mtd_info *mtd, int eb)
+{
+	int ret;
+	loff_t seek;
+
+	if (eb < 0 || eb >= mtd->eb_cnt) {
+		errmsg("bad eraseblock number %d, mtd%d has %d eraseblocks",
+		       eb, mtd->num, mtd->eb_cnt);
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (!mtd->allows_bb)
+		return 0;
+
+	seek = eb * mtd->eb_size;
+	ret = ioctl(mtd->fd, MEMGETBADBLOCK, &seek);
+	if (ret == -1) {
+		sys_errmsg("MEMGETBADBLOCK ioctl failed for "
+			   "eraseblock %d (mtd%d)", eb, mtd->num);
+		return -1;
+	}
+
+	return ret;
+}
+
+/**
+ * mtd_read - read data from an MTD device.
+ * @mtd: MTD device description object
+ * @eb: eraseblock to read from
+ * @offs: offset withing the eraseblock to read from
+ * @buf: buffer to read data to
+ * @len: how many bytes to read
+ *
+ * This function reads @len bytes of data from eraseblock @eb and offset @offs
+ * of the MTD device defined by @mtd and stores the read data at buffer @buf.
+ * Returns %0 in case of success and %-1 in case of failure.
+ */
+int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
+{
+	int ret, rd = 0;
+	off_t seek;
+
+	if (eb < 0 || eb >= mtd->eb_cnt) {
+		errmsg("bad eraseblock number %d, mtd%d has %d eraseblocks",
+		       eb, mtd->num, mtd->eb_cnt);
+		errno = EINVAL;
+		return -1;
+	}
+	if (offs < 0 || offs + len > mtd->eb_size) {
+		errmsg("bad offset %d or length %d, mtd%d eraseblock size is %d",
+		       offs, len, mtd->num, mtd->eb_size);
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* Seek to the beginning of the eraseblock */
+	seek = eb * mtd->eb_size + offs;
+	if (lseek(mtd->fd, seek, SEEK_SET) != seek) {
+		sys_errmsg("cannot seek mtd%d to offset %llu",
+			   mtd->num, (unsigned long long)seek);
+		return -1;
+	}
+
+	while (rd < len) {
+		ret = read(mtd->fd, buf, len);
+		if (ret < 0) {
+			sys_errmsg("cannot read %d bytes from mtd%d (eraseblock %d, offset %d)",
+				   len, mtd->num, eb, offs);
+			return -1;
+		}
+		rd += ret;
+	}
+
+	return 0;
+}
+
+/**
+ * mtd_write - write data to an MTD device.
+ * @mtd: MTD device description object
+ * @eb: eraseblock to write to
+ * @offs: offset withing the eraseblock to write to
+ * @buf: buffer to write
+ * @len: how many bytes to write
+ *
+ * This function writes @len bytes of data to eraseblock @eb and offset @offs
+ * of the MTD device defined by @mtd. Returns %0 in case of success and %-1 in
+ * case of failure.
+ */
+int mtd_write(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
+{
+	int ret;
+	off_t seek;
+
+	if (eb < 0 || eb >= mtd->eb_cnt) {
+		errmsg("bad eraseblock number %d, mtd%d has %d eraseblocks",
+		       eb, mtd->num, mtd->eb_cnt);
+		errno = EINVAL;
+		return -1;
+	}
+	if (offs < 0 || offs + len > mtd->eb_size) {
+		errmsg("bad offset %d or length %d, mtd%d eraseblock size is %d",
+		       offs, len, mtd->num, mtd->eb_size);
+		errno = EINVAL;
+		return -1;
+	}
+#if 0
+	if (offs % mtd->subpage_size) {
+		errmsg("write offset %d is not aligned to mtd%d min. I/O size %d",
+		       offs, mtd->num, mtd->subpage_size);
+		errno = EINVAL;
+		return -1;
+	}
+	if (len % mtd->subpage_size) {
+		errmsg("write length %d is not aligned to mtd%d min. I/O size %d",
+		       len, mtd->num, mtd->subpage_size);
+		errno = EINVAL;
+		return -1;
+	}
+#endif
+
+	/* Seek to the beginning of the eraseblock */
+	seek = eb * mtd->eb_size + offs;
+	if (lseek(mtd->fd, seek, SEEK_SET) != seek) {
+		sys_errmsg("cannot seek mtd%d to offset %llu",
+			   mtd->num, (unsigned long long)seek);
+		return -1;
+	}
+
+	ret = write(mtd->fd, buf, len);
+	if (ret != len) {
+		sys_errmsg("cannot write %d bytes to mtd%d (eraseblock %d, offset %d)",
+			   len, mtd->num, eb, offs);
+		return -1;
+	}
+
+	return 0;
+}