1 files changed, 104 insertions, 0 deletions
diff --git a/src/kernel/fs/initrd.c b/src/kernel/fs/initrd.c
new file mode 100644
index 0000000..b291801
--- /dev/null
+++ b/src/kernel/fs/initrd.c
@@ -0,0 +1,104 @@
+#include <stdint.h>
+#include <kernel/fs/initrd.h>
+#include <kernel/fs/vfs.h>
+#include <kernel/lib/lib.h>
+#include <kernel/lib/alloc.h>
+
+initrd_header_t *initrd_header;
+initrd_file_header_t *file_headers;
+fs_node_t *initrd_root;
+fs_node_t *initrd_dev;
+fs_node_t *root_nodes;
+int nroot_nodes;
+
+struct dirent dirent;
+
+static uint32_t initrd_read(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer) {
+    initrd_file_header_t header = file_headers[node->inode];
+    if (offset > header.length)
+        return 0;
+    if (offset + size > header.length)
+        size = header.length - offset;
+    memcpy(buffer, (uint8_t *) (header.offset + offset), size);
+    return size;
+}
+
+static struct dirent *initrd_readdir(fs_node_t *node, uint32_t index) {
+    if (node == initrd_root && index == 0) {
+        strcpy(dirent.name, "dev");
+        dirent.name[3] = 0;
+        dirent.ino = 0;
+        return &dirent;
+    }
+
+    if (index - 1 >= nroot_nodes)
+        return 0;
+    strcpy(dirent.name, root_nodes[index - 1].name);
+    dirent.name[strlen(root_nodes[index - 1].name)] = 0;
+    dirent.ino = root_nodes[index - 1].inode;
+    return &dirent;
+}
+
+static fs_node_t *initrd_finddir(fs_node_t *node, char *name) {
+    if (node == initrd_root &&
+        !strcmp(name, "dev"))
+        return initrd_dev;
+
+    int i;
+    for (i = 0; i < nroot_nodes; i++)
+        if (!strcmp(name, root_nodes[i].name))
+            return &root_nodes[i];
+    return 0;
+}
+
+fs_node_t *initialise_initrd(uint32_t location) {
+    initrd_header = (initrd_header_t *) location;
+    file_headers = (initrd_file_header_t *) (location + sizeof(initrd_header_t));
+
+    initrd_root = (fs_node_t *) kmalloc(sizeof(fs_node_t));
+    strcpy(initrd_root->name, "initrd");
+    initrd_root->mask = initrd_root->uid = initrd_root->gid = initrd_root->inode = initrd_root->length = 0;
+    initrd_root->flags = FS_DIRECTORY;
+    initrd_root->read = 0;
+    initrd_root->write = 0;
+    initrd_root->open = 0;
+    initrd_root->close = 0;
+    initrd_root->readdir = &initrd_readdir;
+    initrd_root->finddir = &initrd_finddir;
+    initrd_root->ptr = 0;
+    initrd_root->impl = 0;
+
+    initrd_dev = (fs_node_t *) kmalloc(sizeof(fs_node_t));
+    strcpy(initrd_dev->name, "dev");
+    initrd_dev->mask = initrd_dev->uid = initrd_dev->gid = initrd_dev->inode = initrd_dev->length = 0;
+    initrd_dev->flags = FS_DIRECTORY;
+    initrd_dev->read = 0;
+    initrd_dev->write = 0;
+    initrd_dev->open = 0;
+    initrd_dev->close = 0;
+    initrd_dev->readdir = &initrd_readdir;
+    initrd_dev->finddir = &initrd_finddir;
+    initrd_dev->ptr = 0;
+    initrd_dev->impl = 0;
+
+    root_nodes = (fs_node_t *) kmalloc(sizeof(fs_node_t) * initrd_header->nfiles);
+    nroot_nodes = initrd_header->nfiles;
+
+    for (int i = 0; i < initrd_header->nfiles; i++) {
+        file_headers[i].offset += location;
+
+        strcpy(root_nodes[i].name, &file_headers[i].name);
+        root_nodes[i].mask = root_nodes[i].uid = root_nodes[i].gid = 0;
+        root_nodes[i].length = file_headers[i].length;
+        root_nodes[i].inode = i;
+        root_nodes[i].flags = FS_FILE;
+        root_nodes[i].read = &initrd_read;
+        root_nodes[i].write = 0;
+        root_nodes[i].readdir = 0;
+        root_nodes[i].finddir = 0;
+        root_nodes[i].open = 0;
+        root_nodes[i].close = 0;
+        root_nodes[i].impl = 0;
+    }
+    return initrd_root;
+}