diff options
| -rw-r--r-- | subx/020elf.cc | 10 | ||||
| -rw-r--r-- | subx/021translate.cc | 2 | ||||
| -rwxr-xr-x | subx/ex4 | bin | 113 -> 113 bytes | |||
| -rw-r--r-- | subx/ex4.subx | 2 |
4 files changed, 12 insertions, 2 deletions
diff --git a/subx/020elf.cc b/subx/020elf.cc index d5f1e109..807010ea 100644 --- a/subx/020elf.cc +++ b/subx/020elf.cc @@ -6,6 +6,7 @@ if (is_equal(argv[1], "run")) { assert(argc > 2); reset(); cerr << std::hex; + initialize_mem(); load_elf(argv[2]); while (EIP < End_of_program) // weak final-gasp termination check run_one_instruction(); @@ -90,6 +91,15 @@ void load_segment_from_program_header(uint8_t* elf_contents, size_t size, uint32 End_of_program = p_vaddr+p_memsz; } +void initialize_mem() { + // Very primitive/fixed/insecure ELF segments for now. + // code: 0x08048000 -> 0x08048fff + // data: 0x08049000 -> 0x08049fff + // heap: 0x0804a000 -> 0x0804afff + // stack: 0x0804bfff -> 0x0804b000 (downward) + Mem.resize(0x0804c000 - 0x08048000); +} + inline uint32_t u32_in(uint8_t* p) { return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24; } diff --git a/subx/021translate.cc b/subx/021translate.cc index 5757805e..c32b8fef 100644 --- a/subx/021translate.cc +++ b/subx/021translate.cc @@ -34,7 +34,7 @@ void perform_all_transforms(string& program) { // write out the current Memory contents from address 1 to End_of_program to a // bare-bones ELF file with a single section/segment and a hard-coded origin address. void dump_elf(const string& program, const char* filename) { - Mem.resize(1024); + initialize_mem(); // load program into memory, filtering out comments load_program(program, 1); // Not where 'program' should be loaded for running. // But we're not going to run it right now, so we diff --git a/subx/ex4 b/subx/ex4 index 8fd70fbb..b20490ad 100755 --- a/subx/ex4 +++ b/subx/ex4 Binary files differdiff --git a/subx/ex4.subx b/subx/ex4.subx index 98b9f55a..303cba1e 100644 --- a/subx/ex4.subx +++ b/subx/ex4.subx @@ -8,7 +8,7 @@ # fd = 1 bb 1/imm32 # copy 1 to EBX # set location to write to - b9 00 80 04 08 # copy 0x08040000 to ECX + b9 00 90 04 08 # copy 0x08040000 to ECX # size = 1 character ba 1/imm32 # copy 1 to EDX # syscall = read |