diff options
| -rw-r--r-- | src/main.c | 65 |
1 files changed, 65 insertions, 0 deletions
@@ -21,6 +21,8 @@ const u64 lib_signature = 0x0A3E686372613C21; // IMAGE_ARCHIVE_START #define ALIGN(x, align) (((x) + (align - 1U)) / (align)) * (align) +#define ASSERT(x) if (!(x)) { __debugbreak(); } + struct coff_header { u16 machine_type; u16 sections_count; @@ -498,6 +500,52 @@ void read_lib(u8* buffer) { } } +const uint8_t MS_DOS_stub[128] = { + 0x4D, 0x5A, 0x90, 0x00, 0x03, 0x00, 0x00, 0x00, + 0x04, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, + 0xB8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x00, + 0x0E, 0x1F, 0xBA, 0x0E, 0x00, 0xB4, 0x09, 0xCD, + 0x21, 0xB8, 0x01, 0x4C, 0xCD, 0x21, 0x54, 0x68, + 0x69, 0x73, 0x20, 0x70, 0x72, 0x6F, 0x67, 0x72, + 0x61, 0x6D, 0x20, 0x63, 0x61, 0x6E, 0x6E, 0x6F, + 0x74, 0x20, 0x62, 0x65, 0x20, 0x72, 0x75, 0x6E, + 0x20, 0x69, 0x6E, 0x20, 0x44, 0x4F, 0x53, 0x20, + 0x6D, 0x6F, 0x64, 0x65, 0x2E, 0x0D, 0x0D, 0x0A, + 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 +}; + +void write_ms_dos_stub(u8** next_byte) { + // TODO: memcpy + for (u32 index = 0U; index < sizeof(MS_DOS_stub); index++, (*next_byte)++) { + **next_byte = MS_DOS_stub[index]; + } +} + +void write_coff_header(u8** next_byte) { + FILETIME filetime = { 0U }; + GetSystemTimeAsFileTime(&filetime); + + struct coff_header header = { + .machine_type = IMAGE_FILE_MACHINE_AMD64, + .sections_count = 0U, + .timestamp = filetime.dwLowDateTime, + .symbol_table_offset = 0U, + .symbols_count = 0U, + .optional_header_size = 0U, + .characteristics = IMAGE_FILE_EXECUTABLE_IMAGE | IMAGE_FILE_LARGE_ADDRESS_AWARE, + }; + + struct coff_header** header_offset = (struct coff_header**)next_byte; + // This might produce really inneficient code + **header_offset = header; + (*header_offset)++; +} + int mainCRTStartup(void) { char* args_string = VirtualAlloc(NULL, 4096U, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); char** argv = VirtualAlloc(NULL, 4096U, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); @@ -587,9 +635,26 @@ int mainCRTStartup(void) { } else { read_COFF(buffer); } + CloseHandle(file); VirtualFree(buffer, 0U, MEM_RELEASE); } + // TODO: Reserve a huge block and commit when we need more memory + u8* exe_buffer = VirtualAlloc(NULL, 4096U * 10U, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); + u8* next_byte = exe_buffer; + HANDLE output_file = CreateFile("./test.exe", GENERIC_WRITE, 0U, NULL, CREATE_ALWAYS, 0U, NULL); + + write_ms_dos_stub(&next_byte); + write_coff_header(&next_byte); + + DWORD bwrite = 0U; + u64 bytes_to_write = next_byte - exe_buffer; + ASSERT(bytes_to_write <= 0xffffffffU); + + WriteFile(output_file, &exe_buffer, (DWORD)bytes_to_write, &bwrite, NULL); + ASSERT(bwrite == bytes_to_write); + CloseHandle(output_file); + __debugbreak(); VirtualFree(filepath, 0U, MEM_RELEASE); |