very basic vga, ata, serial drivers. start of fat and fs drivers

1 files changed, 21 insertions, 0 deletions

diff --git a/src/kernel/fat.c b/src/kernel/fat.c
new file mode 100644
index 0000000..00fa61f
--- /dev/null
+++ b/src/kernel/fat.c
@@ -0,0 +1,21 @@
+#include "fat.h"
+#include "ata.h"
+#include "panic.h"
+
+void load_fat() {
+  read_sectors(FAT_INFO->reserved_sectors, FAT_INFO->sectors_per_fat, FAT);
+}
+
+uint16_t get_cluster(uint16_t n) {
+  uint32_t t = *(uint32_t *)(FAT + (n / 2) * 3);
+  return (n % 2 ? (t >> 12) : t) & 0xfff;
+}
+
+void set_cluster(uint16_t n, uint16_t v) {
+  uint32_t *t = (uint32_t *)(FAT + (n / 2) * 3);
+  *t = (*t & (n % 2 ? 0xff000fff : 0xfffff000)) | (n % 2 ? v << 12 : v);
+}
+
+uint16_t get_start_cluster(uint8_t *path) {
+  panic("Not implemented (get_start_cluster).");
+}
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