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-rw-r--r--cpu/mpc824x/start.S18
1 files changed, 16 insertions, 2 deletions
diff --git a/cpu/mpc824x/start.S b/cpu/mpc824x/start.S
index bd9706de7c6..18b8e612608 100644
--- a/cpu/mpc824x/start.S
+++ b/cpu/mpc824x/start.S
@@ -278,7 +278,14 @@ SystemCall:
add r11,r11,r0
lwz r11,0(r11)
- li r12,0xd00-4*3 /* save LR & SRRx */
+ li r20,0xd00-4 /* Get stack pointer */
+ lwz r12,0(r20)
+ subi r12,r12,12 /* Adjust stack pointer */
+ li r0,0xc00+_end_back-SystemCall
+ cmplw 0, r0, r12 /* Check stack overflow */
+ bgt 1f
+ stw r12,0(r20)
+
mflr r0
stw r0,0(r12)
mfspr r0,SRR0
@@ -303,7 +310,9 @@ _back:
mtmsr r11
SYNC
- li r12,0xd00-4*3 /* restore regs */
+ li r12,0xd00-4 /* restore regs */
+ lwz r12,0(r12)
+
lwz r11,0(r12)
mtlr r11
lwz r11,4(r12)
@@ -311,8 +320,13 @@ _back:
lwz r11,8(r12)
mtspr SRR1,r11
+ addi r12,r12,12 /* Adjust stack pointer */
+ li r20,0xd00-4
+ stw r12,0(r20)
+
SYNC
rfi
+_end_back:
STD_EXCEPTION(EXC_OFF_TRACE, SingleStep, UnknownException)