Merge branch "preempt" in "trunk".

[bertos.git] / bertos / cpu / avr / hw / switch_ctx_avr.S

diff --git a/bertos/cpu/avr/hw/switch_ctx_avr.S b/bertos/cpu/avr/hw/switch_ctx_avr.S
index 50280292ad7a2e90f73aabc4b8f557a380071bc2..cb10b5f81ab3640bf589ce064d59bf01837393b6 100644 (file)
--- a/bertos/cpu/avr/hw/switch_ctx_avr.S
+++ b/bertos/cpu/avr/hw/switch_ctx_avr.S
@@ -47,12 +47,9 @@ asm_switch_context:
 ;      r0 is the TEMP REG and can be used freely.
 ;      r1 is the ZERO REG and must always contain 0.
 ;
-;      Stack frame is 19 byte, remember to update
+;      Stack frame is 18 byte, remember to update
 ;      CPU_SAVED_REGS_CNT if you change pushed regs.
 
-       in      r0,SREG-__SFR_OFFSET
-       push    r0
-;      push    r1      ;zero-reg
        push    r2
        push    r3
        push    r4
@@ -69,20 +66,9 @@ asm_switch_context:
        push    r15
        push    r16
        push    r17
-;      push    r18     ;caller-save
-;      push    r19     ;caller-save
-;      push    r20     ;caller-save
-;      push    r21     ;caller-save
-;      push    r22     ;caller-save
-;      push    r23     ;caller-save
-;      push    r24     ;caller-save
-;      push    r25     ;caller-save
-;      push    r26     ;caller-save
-;      push    r27     ;caller-save
+
        push    r28
        push    r29
-;      push    r30     ;caller-save
-;      push    r31     ;caller-save
 
        in      r18,SPL-__SFR_OFFSET    ; r18:r19 = SP
        in      r19,SPH-__SFR_OFFSET
@@ -100,25 +86,15 @@ asm_switch_context:
 ;      Two instructions are required to update SP
 ;      so an IRQ can sneak in between them.
 ;      So IRQ *MUST* be disabled and then restored.
+       in      r0, SREG-__SFR_OFFSET
        cli                             ; Disable interrupt
        out     SPL-__SFR_OFFSET,r18    ; SP = *new_sp
        out     SPH-__SFR_OFFSET,r19
        out     SREG-__SFR_OFFSET,r0    ; Restore previous IRQ state
 
-;      pop     r31     ;caller-save
-;      pop     r30     ;caller-save
        pop     r29
        pop     r28
-;      pop     r27     ;caller-save
-;      pop     r26     ;caller-save
-;      pop     r25     ;caller-save
-;      pop     r24     ;caller-save
-;      pop     r23     ;caller-save
-;      pop     r22     ;caller-save
-;      pop     r21     ;caller-save
-;      pop     r20     ;caller-save
-;      pop     r19     ;caller-save
-;      pop     r18     ;caller-save
+
        pop     r17
        pop     r16
        pop     r15
@@ -135,8 +111,5 @@ asm_switch_context:
        pop     r4
        pop     r3
        pop     r2
-;      pop     r1      ;zero-reg
-       pop     r0
-       out     SREG-__SFR_OFFSET,r0
 
        ret