diff options
Diffstat (limited to '069allocate.subx')
| -rw-r--r-- | 069allocate.subx | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/069allocate.subx b/069allocate.subx index 8845c8c3..f7063d2e 100644 --- a/069allocate.subx +++ b/069allocate.subx @@ -16,11 +16,39 @@ # very same 'allocate' helper. They just need a new allocation descriptor for # their book-keeping. +# A default allocation descriptor for programs to use. +== data +Heap: + # curr + 0/imm32 + # limit + 0/imm32 + == code # instruction effective address register displacement immediate # . op subop mod rm32 base index scale r32 # . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes +# Let's start initializing the default allocation descriptor. + +Entry: + # initialize heap + # . Heap = new-segment(64KB) + # . . push args + 68/push Heap/imm32 + 68/push 0x10000/imm32/64KB + # . . call + e8/call new-segment/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + + e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'. +$array-equal-main:end: + # syscall(exit, Num-test-failures) + 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/ebx Num-test-failures/disp32 # copy *Num-test-failures to ebx + b8/copy-to-eax 1/imm32/exit + cd/syscall 0x80/imm8 + # Claim the next 'n' bytes of memory starting at ad->curr and update ad->curr. # Abort if there isn't enough memory in 'ad'. allocate: # ad : (address allocation-descriptor), n : int -> address-or-null/eax |