41 lines
1.0 KiB
Plaintext
41 lines
1.0 KiB
Plaintext
# Some OS-specific preliminaries for Soso.
|
|
|
|
# Memory layout
|
|
#
|
|
# 0x40000000 - 0x40001ffff - for ELF code+data
|
|
# 0x40002000 - 0x401ffffff - for heap
|
|
== code 0x40000000
|
|
== data 0x40001000
|
|
|
|
# Syscalls
|
|
#
|
|
# We don't have libc, so we need to know Soso's precise syscall layout.
|
|
# https://github.com/ozkl/soso/blob/master/kernel/syscalltable.h
|
|
== code
|
|
|
|
syscall_exit: # status/ebx : int
|
|
b8/copy-to-eax 8/imm32
|
|
cd/syscall 0x80/imm8
|
|
|
|
syscall_read: # fd/ebx : int, buf/ecx : addr, size/edx : int -> nbytes-or-error/eax : int
|
|
b8/copy-to-eax 2/imm32
|
|
cd/syscall 0x80/imm8
|
|
c3/return
|
|
|
|
syscall_write: # fd/ebx : int, buf/ecx : addr, size/edx : int -> nbytes-or-error/eax : int
|
|
b8/copy-to-eax 3/imm32
|
|
cd/syscall 0x80/imm8
|
|
c3/return
|
|
|
|
syscall_open: # filename/ebx : (addr kernel-string), flags/ecx : int -> fd-or-error/eax : int
|
|
b8/copy-to-eax 0/imm32
|
|
cd/syscall 0x80/imm8
|
|
c3/return
|
|
|
|
syscall_close: # fd/ebx : int -> status/eax
|
|
b8/copy-to-eax 1/imm32
|
|
cd/syscall 0x80/imm8
|
|
c3/return
|
|
|
|
# anonymous mmap not implemented
|