ack/plat/qemuppc/boot.s
2016-12-09 16:04:21 -05:00

90 lines
1.9 KiB
ArmAsm

#
! $Source: /cvsroot/tack/Ack/plat/linux386/boot.s,v $
! $State: Exp $
! $Revision: 1.3 $
! Declare segments (the order is important).
.sect .text
.sect .rom
.sect .data
.sect .bss
.sect .text
begtext:
! This code is the first thing that runs. The booloader
! passes the Open Firmware pointer in r5.
!
! We keep the bootloader's stack. The ACK expects:
!
! sp+8 environment pointer
! sp+4 argv as a pointer
! sp argc
li32 r3, __openfirmware_ptr
stw r5, 0(r3)
li32 r3, envp
stwu r3, -4(sp)
li32 r3, argv
stwu r3, -4(sp)
li32 r3, 1 ! argc
stwu r3, -4(sp)
bl _openfirmware_init
bl __m_a_i_n
! falls through
.define __exit
.define EXIT
__exit:
EXIT:
! Halt the CPU. This code halts the default G3 emulation of
! qemu-system-ppc. It's wrong for some other CPU models.
#define hid0 0x3f0
#define mfmsr(r) [[31<<26]|[[r]<<21]|0x0a6]
#define mtmsr(r) [[31<<26]|[[r]<<21]|0x124]
mfspr r3, hid0
oris r3, r3, 0x00e0 ! set DOZE, NAP, SLEEP
mtspr hid0, r3 ! in hid0
.data4 mfmsr(3)
oris r3, r3, 0x0004 ! set POW
.data4 mtmsr(3) ! in msr
b EXIT ! If we failed to halt, then spin.
.define _openfirmware_call
_openfirmware_call:
lwz r3, 0(sp)
li32 r4, __openfirmware_ptr
lwz r4, 0(r4)
mtspr ctr, r4
bcctr 20, 0, 0
! Define symbols at the beginning of our various segments, so that we can find
! them. (Except .text, which has already been done.)
.sect .rom; begrom:
.sect .data; begdata:
.sect .bss; begbss:
! The argv and env arrays.
.sect .rom
argv: .data4 exename, 0
envp: .data4 0
exename: .asciz 'qemuppc.img'
! Some magic data. All EM systems need these.
.sect .bss
.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
.comm __openfirmware_ptr, 4 ! OpenFirmware entry point