diff options
Diffstat (limited to 'bfc.S')
| -rw-r--r-- | bfc.S | 160 |
1 files changed, 154 insertions, 6 deletions
@@ -8,7 +8,7 @@ .set F_CREATE_AND_WRITE, 0x41 .set F_MODE_EXECUTABLE, 0744 -.section .constants, "a" +.section constants, "a" c_elf_header: .byte 0x7f # Magic Number @@ -21,21 +21,90 @@ c_elf_header: .hword 0x02 # Executable .hword 0x3e # AMD x86-64 .int 0x1 # ELFv1 - .quad 0x401000 # Entry + .quad 0x4005b0 # Entry .quad 0x40 # Program Header Offset - .quad 0x100 # TODO: Section Header Offset + .quad 0xb0 # TODO: Section Header Offset .int 0x0 # .hword 0x40 # ELF Header Size .hword 0x38 # Program Header Table Entry Size - .hword 0x3 # TODO: Number Of Entries in Program Header Table + .hword 0x2 # TODO: Number Of Entries in Program Header Table .hword 0x40 # Section Header Table Entry Size .hword 0x3 # TODO: Number Of Entries in Section Header Table .hword 0x2 # TODO: Index of Section Header Table Entry containing section names +c_elf_data_program_header: + .int 0x1 # Loadable + .int 0x6 # Read Write + .quad 0x1b0 # Offset in ELF + .quad 0x3001b0 # Virtual Address + .quad 0x3001b0 # Physical Address + .quad 0x400 # Virtual Size + .quad 0x400 # Size in file + .quad 0x1000 # Aligning + +c_elf_data_section_header: + .int 0x1 # Index of name in SHSTRTAB + .int 0x1 # Load as Program data + .quad 0x3 # Is Writable and Readable + .quad 0x3001b0 # Virtual Address + .quad 0x1b0 # Offset in ELF + .quad 0x400 # Size + .int 0x0 # Index + .int 0x0 # Info + .quad 0x1000 # Aligning + .quad 0x0 + +c_elf_shstrtab_section_header: + .int 0xb # Index of name in SHSTRTAB + .int 0x3 # Don't load + .quad 0x0 # No Attributes + .quad 0x0 # Not mapped to virtual memory + .quad 0x170 # Offset in ELF + .quad 0x40 # Size in ELF + .int 0x0 # Index + .int 0x0 # No Inof + .quad 0x1 # Aligning + .quad 0x0 + + +c_elf_shstrtab: + .byte 0 + .asciz "data" + .asciz "code" + .asciz "shstrtab" + +c_elf_data: + .fill 0x400, 1, 0 + c_usage_message: .asciz "bfc [input file] [output file]\n" -.section .variables, "aw" +.section variables, "aw" + +c_elf_code_program_header: + .int 0x1 # Loadable + .int 0x5 # Read Executable + .quad 0x5b0 # Offset in ELF + .quad 0x4005b0 # Virtual Address + .quad 0x4005b0 # Physical Address +v_elf_code_program_header_file_size: + .quad 0x0 # File Size +v_elf_code_program_header_memory_size: + .quad 0x0 # Memory Size + .quad 0x1000 # Aligning + +c_elf_code_section_header: + .int 0x6 # Index of name in SHSTRTAB + .int 0x1 # Load as program data + .quad 0x6 # Is Readable and Executable + .quad 0x4005b0 # Virtual Address + .quad 0x5b0 # Offset in ELF +v_elf_code_section_header_size: + .quad 0x0 + .int 0x0 # Index + .int 0x0 # Info + .quad 0x1000 # Aligning + .quad 0x0 v_input_fd: .int 0x0 @@ -56,7 +125,7 @@ v_input_char: .byte 0x0 -.section .code, "ax" +.section code, "ax" .global _start _start: mov %rsp, %rbp @@ -90,6 +159,7 @@ l_read_loop: jmp l_read_loop l_compile_move_left: + # TODO: fix buffer overflows mov $v_buffer_cursor, %rbx mov (%rbx), %rsi add $3, %rsi @@ -104,6 +174,17 @@ l_compile_move_left: jmp l_read_loop l_compile_move_right: + # TODO: fix buffer overflows + mov $v_buffer_cursor, %rbx + mov (%rbx), %rsi + add $3, %rsi + call f_check_buffer + + mov $v_buffer_cursor, %rbx + mov (%rbx), %rax + movl $0xc8ff48, (%rax) + add $3, %rax + mov %rax, (%rbx) jmp l_read_loop l_compile_inc: @@ -125,6 +206,66 @@ l_compile_read: jmp l_read_loop l_read_loop_end: + mov $v_buffer_cursor, %rbx + mov (%rbx), %rax + movl $0x3cc0c748, (%rax) + add $7, %rax + movl $0x050f, (%rax) + add $2, %rax + mov %rax, (%rbx) + + + mov $v_buffer_cursor, %rbx + mov (%rbx), %rax + mov $v_buffer_start, %rbx + mov (%rbx), %rbx + sub %rbx, %rax + mov %rax, %r12 + + mov $v_elf_code_program_header_file_size, %rbx + mov %rax, (%rbx) + mov $v_elf_code_program_header_memory_size, %rbx + mov %rax, (%rbx) + mov $v_elf_code_section_header_size, %rbx + mov %rax, (%rbx) + + + mov $c_elf_header, %rsi + mov $0x40, %rdx + call f_write_to_output + + mov $c_elf_data_program_header, %rsi + mov $0x38, %rdx + call f_write_to_output + + mov $c_elf_code_program_header, %rsi + mov $0x38, %rdx + call f_write_to_output + + mov $c_elf_data_section_header, %rsi + mov $0x40, %rdx + call f_write_to_output + + mov $c_elf_code_section_header, %rsi + mov $0x40, %rdx + call f_write_to_output + + mov $c_elf_shstrtab_section_header, %rsi + mov $0x40, %rdx + call f_write_to_output + + mov $c_elf_shstrtab, %rsi + mov $0x40, %rdx + call f_write_to_output + + mov $c_elf_data, %rsi + mov $0x400, %rdx + call f_write_to_output + + mov $v_buffer_start, %rbx + mov (%rbx), %rsi + mov %r12, %rdx + call f_write_to_output call f_close_files mov $0, %rdi @@ -135,6 +276,13 @@ f_exit: mov $SYS_EXIT, %rax syscall +/* rsi = buffer, %rdx = len */ +f_write_to_output: + mov $SYS_WRITE, %rax + mov $v_output_fd, %rbx + mov (%rbx), %rdi + syscall + f_check_args: mov (%rbp), %rax |