From b8cafaf24dec1c573f878ea8e78616b328ee5670 Mon Sep 17 00:00:00 2001
From: antifallobst <antifallobst@systemausfall.org>
Date: Sun, 7 May 2023 23:14:43 +0200
Subject: [PATCH] feature (MBR): implemented MBR

---
 inc/drivers/fs/mbr.h | 40 ++++++++++++++++++++++++++++++++++++++++
 src/drivers/ahci.c   | 20 +++++++++++++++++---
 src/drivers/fs/mbr.c | 16 ++++++++++++++++
 3 files changed, 73 insertions(+), 3 deletions(-)
 create mode 100644 inc/drivers/fs/mbr.h
 create mode 100644 src/drivers/fs/mbr.c

diff --git a/inc/drivers/fs/mbr.h b/inc/drivers/fs/mbr.h
new file mode 100644
index 0000000..fa13f9c
--- /dev/null
+++ b/inc/drivers/fs/mbr.h
@@ -0,0 +1,40 @@
+// This file is part of noxos and licensed under the MIT open source license
+
+#ifndef KERNEL_MBR_H
+#define KERNEL_MBR_H
+
+#include "utils/stdtypes.h"
+#include "utils/string.h"
+
+typedef enum {
+    MBR_PARTITION_TYPE_UNUSED    = 0x00,
+    MBR_PARTITION_TYPE_GPT       = 0xEE,
+    MBR_PARTITION_TYPE_EXT2      = 0x83,
+    MBR_PARTITION_TYPE_FAT12     = 0x01,
+    MBR_PARTITION_TYPE_FAT16     = 0x04,
+    MBR_PARTITION_TYPE_FAT32_CHS = 0x0B,
+    MBR_PARTITION_TYPE_FAT32_LBA = 0x0C
+} mbr_partition_types_E;
+
+typedef struct {
+    uint8_t     boot_indicator;
+    uint8_t     start_head;
+    uint16_t    start_sector:6;
+    uint16_t    start_cylinder:10;
+    uint8_t     partition_type;
+    uint8_t     end_head;
+    uint16_t    end_sector:6;
+    uint16_t    end_cylinder:10;
+    uint32_t    start_lba;
+    uint32_t    num_sectors;
+}__attribute__((packed)) mbr_partition_header_T;
+
+typedef struct {
+    uint8_t                 bootstrap   [446];
+    mbr_partition_header_T  partitions  [4];
+    uint8_t                 signature   [2];
+} mbr_header_T;
+
+string_t mbr_partition_type_to_string(mbr_partition_types_E type);
+
+#endif //KERNEL_MBR_H
diff --git a/src/drivers/ahci.c b/src/drivers/ahci.c
index 35a664d..41d355c 100644
--- a/src/drivers/ahci.c
+++ b/src/drivers/ahci.c
@@ -1,6 +1,7 @@
 // This file is part of noxos and licensed under the MIT open source license
 
 #include "drivers/ahci.h"
+#include "drivers/fs/mbr.h"
 #include "utils/memory.h"
 #include "utils/logger.h"
 #include "mm/page_map.h"
@@ -50,9 +51,22 @@ ahci_controller_T* ahci_controller_alloc(pci_device_T* pci_device) {
     for (int i = 0; i < controller->num_ports; i++) {
         log(LOG_INFO, "    %s", g_ahci_device_type_strings[controller->ports[i].type]);
         ahci_port_init(&controller->ports[i]);
-        uint8_t* buffer = memory_allocate(512 + PFRAME_SIZE);
-        if (ahci_port_read(&controller->ports[i], 0, 1, CEIL_TO((uint64_t)buffer, PFRAME_SIZE)))
-            memory_hexdump(CEIL_TO((uint64_t)buffer, PFRAME_SIZE), 512);
+
+        uint8_t* addr = memory_allocate(512 + PFRAME_SIZE);
+        void* buffer = (void*)CEIL_TO((uint64_t)addr, PFRAME_SIZE);
+
+        if (ahci_port_read(&controller->ports[i], 0, 1, buffer)) {
+            mbr_header_T* mbr = (mbr_header_T*)buffer;
+
+            log(LOG_INFO, "      MBR:");
+            for (int j = 0; j < 4; j++) {
+                mbr_partition_types_E type = mbr->partitions[j].partition_type;
+                if (type == MBR_PARTITION_TYPE_UNUSED) continue;
+                log(LOG_INFO, "        p%d: 0x%xb - %s", j, type, mbr_partition_type_to_string(type));
+            }
+        }
+
+        memory_free(addr);
     }
 
     return controller;
diff --git a/src/drivers/fs/mbr.c b/src/drivers/fs/mbr.c
new file mode 100644
index 0000000..75eaad6
--- /dev/null
+++ b/src/drivers/fs/mbr.c
@@ -0,0 +1,16 @@
+// This file is part of noxos and licensed under the MIT open source license
+
+#include "drivers/fs/mbr.h"
+
+string_t mbr_partition_type_to_string(mbr_partition_types_E type) {
+    switch (type) {
+        case MBR_PARTITION_TYPE_UNUSED:     return "Unused";
+        case MBR_PARTITION_TYPE_GPT:        return "GUID Partition Table";
+        case MBR_PARTITION_TYPE_EXT2:       return "EXT2";
+        case MBR_PARTITION_TYPE_FAT12:      return "FAT12";
+        case MBR_PARTITION_TYPE_FAT16:      return "FAT16";
+        case MBR_PARTITION_TYPE_FAT32_CHS:  return "FAT32 (CHS)";
+        case MBR_PARTITION_TYPE_FAT32_LBA:  return "FAT32 (LBA)";
+        default:                            return "Unknown";
+    }
+}
\ No newline at end of file