diff options
Diffstat (limited to 'subx/012elf.cc')
-rw-r--r-- | subx/012elf.cc | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/subx/012elf.cc b/subx/012elf.cc index 11e0e4bc..d0a3fbd2 100644 --- a/subx/012elf.cc +++ b/subx/012elf.cc @@ -134,13 +134,20 @@ void load_segment_from_program_header(uint8_t* elf_contents, int segment_index, // code: 0x09000000 -> 0x09ffffff (specified in ELF binary) // data: 0x0a000000 -> 0x0affffff (specified in ELF binary) // --- heap gets mmap'd somewhere here --- -// stack: 0xbdffffff -> 0xbd000000 (downward; not in ELF binary) -// argv hack: 0xbf000000 -> 0xc0000000 (not in ELF binary) +// stack: 0x7dffffff -> 0x7d000000 (downward; not in ELF binary) +// argv hack: 0x7f000000 -> 0x7fffffff (not in ELF binary) +// +// For now we avoid addresses with the most significant bit set; SubX doesn't +// support unsigned comparison yet (https://github.com/akkartik/mu/issues/30) +// Once we do, we can go up to 0xc0000000; higher addresses are reserved for +// the Linux kernel. const int CODE_SEGMENT = 0x09000000; const int DATA_SEGMENT = 0x0a000000; -const int STACK_SEGMENT = 0xbd000000; -const int AFTER_STACK = 0xbe000000; -const int ARGV_DATA_SEGMENT = 0xbf000000; +const int STACK_SEGMENT = 0x7d000000; +const int AFTER_STACK = 0x7e000000; +const int ARGV_DATA_SEGMENT = 0x7f000000; +// When updating the above memory map, don't forget to update `mmap`'s +// implementation in the 'syscalls' layer. :(before "End Dump Info for Instruction") //? dump_stack(); // slow :(code) |