ack/plat/linuxmips/boot.s
2018-09-18 23:39:04 +02:00

59 lines
1.3 KiB
ArmAsm

#
! Declare segments (the order is important).
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
.define .entry
.entry:
! This code is placed at the beginning of the ELF 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 ptr to argv
! sp ptr to env
lw r4, 0(sp) ! r4 = argc
addiu r5, sp, 4 ! r5 = argv
sll r6, r4, 2 ! r6 = argc*4
addu r6, r6, r5 ! r6 = null after last arg
addiu r6, r6, 4 ! r6 = env
addiu sp, sp, -3 * 4
sw r4, 0(sp) ! argc
sw r5, 4(sp) ! argv
sw r6, 8(sp) ! envp
j __m_a_i_n
nop
! Define symbols at the beginning of our various segments, so that we can find
! them. (Except .text, which has already been done.)
.sect .data; begdata:
.sect .rom; begrom:
.sect .bss; begbss:
! Some magic data. All EM systems need these.
.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