ack/plat/osx386/boot.s

68 lines
1.2 KiB
ArmAsm
Raw Permalink Normal View History

! plat/osx386/boot.s
! Declare segments (the order is important).
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
begtext:
! This code is placed at the entry point of the Mach-o
! executable and is the first thing that runs.
!
! On entry, the stack looks like this:
!
! sp+.. NULL
! sp+8+(4*argc) env (X quads)
! sp+4+(4*argc) NULL
! sp+4 argv (argc quads)
! sp argc
!
! The ACK actually expects:
!
! sp+8 argc
! sp+4 argv
! sp env
mov eax, (esp) ! eax = argc
lea ebx, 4(esp) ! ebx = argv
lea ecx, (esp)(eax*4)
add ecx, 12 ! environ
push ecx ! environ
push ebx ! argc
push eax ! argv
push eax ! dummy, representing the return argument
xor ebp, ebp
jmp __m_a_i_n
! This provides an emergency exit routine used by EM.
.define EXIT
.extern EXIT
EXIT:
push 1
jmp __exit
.sect .rom
begrom:
.sect .data
begdata:
! Some magic data. All EM systems need these.
.sect .bss
begbss:
.define _errno
.comm _errno, 4 ! Posix errno storage
.define .trppc, .ignmask
.comm .trppc, 4 ! ptr to user trap handler
.comm .ignmask, 4 ! user trap ignore mask