Add some basic code, build kernel stuff in tree

sw/kernel/filesystems/fat32_c.c

@@ -0,0 +1,26 @@
+#include "fat32.h"
+#include <devices/sd_card.h>
+#include <conio.h>
+
+#include <stdint.h>
+
+uint8_t fat32_read_cluster(uint32_t cluster, void* buf) {
+    uint8_t error;
+    uint32_t addr = (cluster - 2) + data_start_sector;
+    SD_readSingleBlock(addr, buf, &error);
+    return error;
+}
+
+uint8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dentry) {
+    struct fat32_directory_entry* local_entry;
+    int i = 0;
+    fat32_read_cluster(root_cluster, sd_buf);
+    for (i = 0; i < 16; i++){
+        local_entry = sd_buf + i*32;
+        if (local_entry->attr1 == 0xf || local_entry->attr1 & 0x8 || !local_entry->attr1) {
+            continue;
+        }
+        cprintf("Name: %.11s\n", local_entry->file_name, local_entry->file_ext);
+        cprintf("attr1: %x\n", local_entry->attr1);
+    }
+}