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/* Copyright (c) 2002, Marek Michalkiewicz
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name of the copyright holders nor the names of
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. */
/*
setjmp.S
Contributors:
Created by Marek Michalkiewicz <marekm@linux.org.pl>
*/
/*
jmp_buf:
offset size description
0 16 call-saved registers (r2-r17)
16 2 frame pointer (r29:r28)
18 2 stack pointer (SPH:SPL)
20 1 status register (SREG)
21 3 return address (PC) (2 bytes used for <=128K flash)
24 = total size
int setjmp(jmp_buf __jmpb);
void longjmp(jmp_buf __jmpb, int __val) __attribute__((noreturn));
*/
#include "macros.inc"
#include "ctoasm.inc"
/* the same library is used for 2313 and 8515 for now -
I hope writing 0 to non-existent SPH doesn't hurt... */
#ifndef SPH
#define SPH (SPL+1)
#endif
#define jmpb_hi rP0
#define jmpb_lo rP1
#define val_hi rP2
#define val_lo rP3
#define ret_lo rP1 /* r24 */
#define ret_hi rP0 /* r25 */
.section .text
.global _U(setjmp)
.global _U(longjmp)
_U(setjmp):
LOAD_Z(jmpb_lo, jmpb_hi)
in r26, _SFR_IO_ADDR(SPL)
in r27, _SFR_IO_ADDR(SPH)
/* save program counter (return address) */
/* return address on stack (pushed by "call") is big endian! */
/* SP is post-decremented by "call" */
adiw r26, 1
#ifdef EIND /* devices with >128K bytes of flash - none yet */
ld __tmp_reg__, X+
std Z+23, __tmp_reg__
#endif
ld __tmp_reg__, X+
std Z+22, __tmp_reg__
ld __tmp_reg__, X
std Z+21, __tmp_reg__
/* save stack pointer (SP value before calling this function) */
std Z+18,r26
std Z+19,r27
/* save status register (I flag) */
in __tmp_reg__, _SFR_IO_ADDR(SREG)
std Z+20, __tmp_reg__
/* save call-saved registers */
st Z, r2
std Z+1, r3
std Z+2, r4
std Z+3, r5
std Z+4, r6
std Z+5, r7
std Z+6, r8
std Z+7, r9
std Z+8, r10
std Z+9, r11
std Z+10, r12
std Z+11, r13
std Z+12, r14
std Z+13, r15
std Z+14, r16
std Z+15, r17
/* save frame pointer */
std Z+16,r28
std Z+17,r29
/* return zero */
clr ret_lo
clr ret_hi
ret
_U(longjmp):
LOAD_X(jmpb_lo, jmpb_hi)
/* return value */
mov ret_lo, val_lo
mov ret_hi, val_hi
/* if zero, change to 1 */
cpi ret_lo, 1
cpc ret_hi, __zero_reg__
adc ret_lo, __zero_reg__
/* restore call-saved registers */
ld r2, X+
ld r3, X+
ld r4, X+
ld r5, X+
ld r6, X+
ld r7, X+
ld r8, X+
ld r9, X+
ld r10, X+
ld r11, X+
ld r12, X+
ld r13, X+
ld r14, X+
ld r15, X+
ld r16, X+
ld r17, X+
/* restore frame pointer */
ld YL, X+
ld YH, X+
/* restore stack pointer (SP value before the setjmp() call) */
ld r30,X+
ld r31,X+
ld __tmp_reg__, X+
/* interrupts disabled for shortest possible time (3 cycles) */
cli
out _SFR_IO_ADDR(SPH), r31
/* Restore status register (including the interrupt enable flag).
Interrupts are re-enabled only after the next instruction. */
out _SFR_IO_ADDR(SREG), __tmp_reg__
out _SFR_IO_ADDR(SPL), r30
/* restore return address */
ld r30,X+
ld r31,X+
#ifdef EIND
ld __tmp_reg__, X
out _SFR_IO_ADDR(EIND), __tmp_reg__
.word 0x9419 /* eijmp */
#else
ijmp
#endif
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