feat! firmware breaking changes on the API.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

1 files changed, 104 insertions, 0 deletions

diff --git a/include/partition-map.h b/include/partition-map.h
new file mode 100644
index 0000000..c3088fe
--- /dev/null
+++ b/include/partition-map.h
@@ -0,0 +1,104 @@
+/* -------------------------------------------
+
+  Copyright (C) 2024-2025, Amlal El Mahrouss, licensed under Apache 2.0.
+
+------------------------------------------- */
+
+#ifndef __PARTITION_MAP_H__
+#define __PARTITION_MAP_H__
+
+#include <include/boot.h>
+
+/* @brief AMD64 magic for EPM */
+#define EPM_MAGIC_X86 "EPMAM"
+
+/* @brief RISC-V magic for EPM */
+#define EPM_MAGIC_RV "EPMRV"
+
+/* @brief ARM magic for EPM */
+#define EPM_MAGIC_ARM "EPMAR"
+
+/* @brief 64x0 magic for EPM */
+#define EPM_MAGIC_64X0 "EPM64"
+
+/* @brief 32x0 magic for EPM */
+#define EPM_MAGIC_32X0 "EPM32"
+
+/* @brief POWER magic for EPM */
+#define EPM_MAGIC_PPC "EPMPC"
+
+#ifdef __aarch64__
+#define EPM_MAGIC EPM_MAGIC_ARM
+#elif defined(__riscv64__)
+#define EPM_MAGIC EPM_MAGIC_RV
+#else
+#define EPM_MAGIC "EPMMS" /* mass storage */
+#endif
+
+#define EPM_MAX_BLKS (128) /* 1 on UEFI EPM, because of it would only fit on a sector. */
+
+/// @brief Size of a partition block (roughly 512 bytes)
+#define EPM_PART_BLK_SZ sizeof(struct part_block)
+
+/// @brief Start of EPM headers.
+/// @note There could be anything before this LBA.
+/// Such as PC specific structures.
+#define EPM_PART_BLK_START (0)
+
+/// @brief EPM revision (actually at version 2)
+#define EPM_REVISION (2U)
+
+/// @brief EPM GUID block.
+typedef struct boot_guid {
+  uint32_t data1;
+  uint16_t data2;
+  uint16_t data3;
+  uint8_t  data4[8];
+} __attribute__((packed)) boot_guid_t;
+
+/* The first 0 > 128 addresses of a disk contains these headers. */
+
+/**
+ * @brief The EPM partition block.
+ * used to represent a partition inside a media.
+ */
+struct __attribute__((packed)) part_block {
+  ascii_char_t magic[5];
+  ascii_char_t name[32];
+  boot_guid_t  uuid;
+  int32_t      version;
+  int32_t      num_blocks;
+  int64_t      lba_start;
+  int64_t      sector_sz;
+  int64_t      lba_end;
+  int16_t      type;
+  int32_t      fs_version;
+  ascii_char_t fs[16]; /* ffs_2 */
+  ascii_char_t reserved[401];
+};
+
+typedef struct part_block part_block_t;
+
+///! @brief variant enum.
+///! use it in the boot block version field.
+enum {
+  EPM_INVALID     = 0x00,
+  EPM_GENERIC_OS  = 0xcf,
+  EPM_LINUX       = 0x8f,
+  EPM_BSD         = 0x9f,
+  EPM_NEKERNEL_OS = 0x1f,
+  EPM_LEGACY_OS   = 0x2f,
+};
+
+/// @brief check for supported filesystem.
+boolean cb_filesystem_exists(caddr_t fs, size_t len);
+
+/// @brief Parse EPM block from blob.
+bool cb_parse_partition_block_data_at(voidptr_t blob, size_t blob_sz, size_t index, size_t* end_lba,
+                                      size_t* start_lba, size_t* sector_sz);
+
+/// @brief Parse Partition block info at index.
+/// @param index the partition block to parse.
+part_block_t* cb_parse_partition_block_at(voidptr_t blob, size_t blob_sz, size_t index);
+
+#endif  // ifndef __PARTITION_MAP_H__