1 files changed, 31 insertions, 0 deletions
diff --git a/stage3/fs.c b/stage3/fs.c
new file mode 100644
index 0000000..9f7ea51
--- /dev/null
+++ b/stage3/fs.c
@@ -0,0 +1,31 @@
+#include "fs.h"
+#include "ata.h"
+#include "string.h"
+#include "memory.h"
+#include "heap.h"
+
+file fs_read(const char *filename)
+{
+	u64 start = (*(u32 *) (0x1000-10-8))/512;
+
+	for (;;) {
+		u8 *info = ata_read_full(start, 1);
+
+		if (memcmp(info+257, "ustar", 5) != 0) {
+			free(info);
+			return (file) { .len = 0, .data = nil };
+		}
+
+		u8 *infop = info+124;
+		usize fsize = parse_num(&infop, 8, 11);
+		usize fsect = (fsize+511)/512;
+
+		if (memcmp(info, filename, strlen(filename) + 1) == 0) {
+			free(info);
+			return (file) { .len = fsize, .data = ata_read_full(start+1, fsect) };
+		} else {
+			free(info);
+			start += 1 + fsect;
+		}
+	}
+}