diff options
Diffstat (limited to 'config/macintosh/powerpc.s')
| -rw-r--r-- | config/macintosh/powerpc.s | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/config/macintosh/powerpc.s b/config/macintosh/powerpc.s new file mode 100644 index 0000000..71724a6 --- /dev/null +++ b/config/macintosh/powerpc.s @@ -0,0 +1,52 @@ +# coswitch(old, new, first) +# GPR3 GPR4 GPR5 + +# This code is modeled after the ppc_aix context switch +# it was compared to the Darwin context switch routine to +# get the syntax correct for the Apple gcc compiler. +.macro ENTRY + .text + .align 2 + .globl $0 +$0: +.endmacro + + .file "rswitch.s" + .set RSIZE, 80 ; room for regs 13-31, rounded up mod16 + + ENTRY _coswitch + + stwu r1, -RSIZE(r1) ; allocate stack frame + + ; Save Old Context: + stw r1, 0(r3) ; SP + stw r2, 4(r3) ; TOC + mflr r0 + stw r0, 8(r3) ; LR (return address) + mfcr r0 + stw r0, 12(r3) ; CR + stmw r13, -RSIZE(r1) ; GPRs 13-31 (save on stack) + + cmpi 0, r5, 0 + beq first ; if first time + + ; Restore new context: + lwz r1, 0(r4) ; SP + lwz r2, 4(r4) ; TOC + lwz r0, 8(r4) ; LR + mtlr r0 + lwz r0, 12(r4) ; CR + mtcr r0 + lmw r13, -RSIZE(r1) ; GPRs 13-31 (from stack) + + addic r1, r1, RSIZE ; deallocate stack frame + blr ; return into new context + +first: ; First-time call: + lwz r1, 0(r4) ; SP as figured by Icon + addic r1, r1, -64 ; save area for callee + addi r3, 0, 0 ; arg1 + addi r4, 0, 0 ; arg2 + bl _new_context ; new_context(0,0) + addi r3, 0, 0 + bl _syserr |