fat_io_lib finally works, implement virtual partition devices, manage devices via string keys

kernel/device/partitions.h

@@ -0,0 +1,27 @@
+#ifndef _KERNEL_DEVICE_PARTITIONS_H
+#define _KERNEL_DEVICE_PARTITIONS_H
+
+#include <aux/compiler.h>
+#include <device/device.h>
+#include <libk/std.h>
+
+struct dos_pte {
+  uint8_t drive_attrs;
+  uint8_t chs_start_addr[3];
+  uint8_t part_type;
+  uint8_t chs_last_sect_addr[3];
+  uint32_t start_lba;
+  uint32_t sector_count;
+} PACKED;
+
+struct dos_mbr {
+  uint8_t boot_code[440];
+  uint8_t signature[4];
+  uint8_t resv[2];
+  struct dos_pte ptes[4];
+  uint8_t valid_sign[2];
+} PACKED;
+
+int device_probe_partitions (struct device* device);
+
+#endif // _KERNEL_DEVICE_PARTITIONS_H