Initial commit

Added base code, can run ELF files and simulate RV32I instructions
2023-10-04 21:28:18 +02:00
commit 981c35584c
17 changed files with 1280 additions and 0 deletions
@@ -0,0 +1,83 @@
+#ifndef ELF_H
+#define ELF_H
+
+/*
+ * ELF handling
+ * Valentin HAUDIQUET
+ * Sources are :
+ * - https://refspecs.linuxfoundation.org/elf/elf.pdf (ELF Reference)
+ * - https://wiki.osdev.org/ELF (OSDev)
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+
+typedef struct ELF_HEADER_32
+{
+	uint8_t ELF[4];
+	uint8_t bits;       // 1 = 32bits, 2 = 64bits
+	uint8_t endianness; // 1 = little, 2 = big
+	uint8_t header_version;
+	uint8_t abi;
+	uint8_t padding0[8];
+	uint16_t exec_type; // 1 = relocatable, 2 = executable, 3 = shared, 4 = core
+	uint16_t instruction_set;
+	uint32_t elf_version;
+	uint32_t entry_32;
+	uint32_t program_header_table_32;
+	uint32_t section_table_32;
+	uint32_t flags;
+	uint16_t header_size;
+	uint16_t program_entry_size;
+	uint16_t program_entry_amount;
+	uint16_t section_entry_size;
+	uint16_t section_entry_amount;
+	uint16_t section_str_index; // Index of string table associated with section names
+} __attribute__((packed)) elf_header_32_t;
+
+#define ELF_LITTLE_ENDIAN 1
+#define ELF_BIG_ENDIAN 2
+
+#define BITS_32 1
+#define BITS_64 2
+
+#define INSTRUCTION_SET_X86 0x3
+#define INSTRUCTION_SET_X86_64 0x3E
+#define INSTRUCTION_SET_RISCV 0xF3
+
+typedef struct ELF_SECTION_HEADER_32
+{
+	uint16_t section_name;
+	uint16_t section_type;
+	uint16_t section_flags;
+	uint32_t section_addr_32;
+	uint32_t section_offset_32;
+	uint16_t section_size;
+	uint16_t section_link;
+	uint16_t section_info;
+	uint16_t section_addralign;
+	uint16_t section_entrysize;
+} __attribute__((packed)) elf_section_header_32_t;
+
+typedef struct ELF_PROGRAM_HEADER_32
+{
+    uint32_t segment_type;
+    uint32_t segment_offset;
+    uint32_t virtual_address;
+    uint32_t undefined;
+    uint32_t segment_file_size;
+    uint32_t segment_memory_size;
+    uint32_t flags;
+    uint32_t align;
+} __attribute__((packed)) elf_program_header_32_t;
+
+#define SEGMENT_TYPE_NULL 0
+#define SEGMENT_TYPE_LOAD 1
+#define SEGMENT_TYPE_DYNAMIC 2
+#define SEGMENT_TYPE_INTERP 3
+#define SEGMENT_TYPE_NOTE 4
+
+uint32_t elf_32_load(void* file);
+
+#endif