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-rw-r--r--kernel/block/partitions/cmdline.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/kernel/block/partitions/cmdline.c b/kernel/block/partitions/cmdline.c
new file mode 100644
index 000000000..5141b563a
--- /dev/null
+++ b/kernel/block/partitions/cmdline.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2013 HUAWEI
+ * Author: Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ * Read block device partition table from the command line.
+ * Typically used for fixed block (eMMC) embedded devices.
+ * It has no MBR, so saves storage space. Bootloader can be easily accessed
+ * by absolute address of data on the block device.
+ * Users can easily change the partition.
+ *
+ * The format for the command line is just like mtdparts.
+ *
+ * For further information, see "Documentation/block/cmdline-partition.txt"
+ *
+ */
+
+#include <linux/cmdline-parser.h>
+
+#include "check.h"
+#include "cmdline.h"
+
+static char *cmdline;
+static struct cmdline_parts *bdev_parts;
+
+static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
+{
+ int label_min;
+ struct partition_meta_info *info;
+ char tmp[sizeof(info->volname) + 4];
+ struct parsed_partitions *state = (struct parsed_partitions *)param;
+
+ if (slot >= state->limit)
+ return 1;
+
+ put_partition(state, slot, subpart->from >> 9,
+ subpart->size >> 9);
+
+ info = &state->parts[slot].info;
+
+ label_min = min_t(int, sizeof(info->volname) - 1,
+ sizeof(subpart->name));
+ strncpy(info->volname, subpart->name, label_min);
+ info->volname[label_min] = '\0';
+
+ snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+
+ state->parts[slot].has_info = true;
+
+ return 0;
+}
+
+static int __init cmdline_parts_setup(char *s)
+{
+ cmdline = s;
+ return 1;
+}
+__setup("blkdevparts=", cmdline_parts_setup);
+
+/*
+ * Purpose: allocate cmdline partitions.
+ * Returns:
+ * -1 if unable to read the partition table
+ * 0 if this isn't our partition table
+ * 1 if successful
+ */
+int cmdline_partition(struct parsed_partitions *state)
+{
+ sector_t disk_size;
+ char bdev[BDEVNAME_SIZE];
+ struct cmdline_parts *parts;
+
+ if (cmdline) {
+ if (bdev_parts)
+ cmdline_parts_free(&bdev_parts);
+
+ if (cmdline_parts_parse(&bdev_parts, cmdline)) {
+ cmdline = NULL;
+ return -1;
+ }
+ cmdline = NULL;
+ }
+
+ if (!bdev_parts)
+ return 0;
+
+ bdevname(state->bdev, bdev);
+ parts = cmdline_parts_find(bdev_parts, bdev);
+ if (!parts)
+ return 0;
+
+ disk_size = get_capacity(state->bdev->bd_disk) << 9;
+
+ cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
+
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ return 1;
+}