mufs: initial support for mounting/formatting

include/fs/mufs.h

@@ -0,0 +1,12 @@
+#pragma once
+
+struct flash_dev;
+
+struct mufs {
+	struct flash_dev *dev;
+	uint32_t nblocks;
+	uint32_t root;
+};
+
+int mufs_mount(struct mufs *fs, struct flash_dev *dev);
+int mufs_format(struct flash_dev *dev);

source/fs/mufs/super.c

@@ -0,0 +1,47 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <flash.h>
+
+#include <fs/mufs.h>
+
+struct mufs_super {
+	char magic[4];
+	uint32_t nblocks;
+	uint32_t root;
+} __attribute__((packed));
+
+int mufs_mount(struct mufs *fs, struct flash_dev *dev)
+{
+	struct mufs_super super;
+
+	if (!fs || !dev)
+		return -1;
+
+	if (flash_read(dev, 0, &super, sizeof super) == 0)
+		return -1;
+
+	if (memcmp(super.magic, "mufs", 4) != 0)
+		return -1;
+
+	fs->dev = dev;
+	fs->nblocks = super.nblocks;
+	fs->root = super.root;
+
+	return 0;
+}
+
+int mufs_format(struct flash_dev *dev)
+{
+	struct mufs_super super;
+
+	memcpy(super.magic, "mufs", 4);
+	super.nblocks = flash_get_capacity(dev) >> dev->log2_block_size;
+	super.root = 0;
+
+	if (flash_write(dev, 0, &super, sizeof super) == 0)
+		return -1;
+
+	return 0;
+}