ORCALib/setjmp.asm

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2017-10-31 17:14:07 +00:00
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****************************************************************
*
* SetJmp - Set jump library
*
* This code implements the subroutines needed to support the
* standard C library SETJMP.
*
* January 1989
* Mike Westerfield
*
* Copyright 1989
* Byte Works, Inc.
*
****************************************************************
*
SetJmp start dummy segment
end
****************************************************************
*
* int setjmp(env)
* jmp_buf env;
*
* Inputs:
* env - pointer to the environment array
*
* Outputs:
* Returns 0.
*
****************************************************************
*
setjmp start
env equ 4 pointer to array
ret equ 1 return address
tsc set up addressing
phd
tcd
clc save the correct stack pointer
adc #4
sta [env]
ldy #2 save D
lda 1,S
sta [env],Y
ldy #4 save the return address
lda ret-1
sta [env],Y
iny
iny
lda ret+1
sta [env],Y
pld repair the stack
phb
plx
ply
pla
pla
phy
phx
plb
lda #0 return 0
rtl
end
****************************************************************
*
* void longjmp(env,status)
* jmp_buf env;
* int status;
*
* Inputs:
* env - pointer to the environment array
* status - status to return
*
****************************************************************
*
longjmp start
env equ 4 environment pointer
status equ 8 status to return
tsc set up the local stack frame
tcd
phb
phk
plb
ldx status get the status
bne lb1
inx
lb1 ldy #6 get the env record
lb2 lda [env],Y
sta lenv,Y
dey
dey
bpl lb2
plb
lda >stackPtr reset the stack pointer
tcs
lda >ret+2 reset the return address
sta 2,S
lda >ret
sta 0,S
lda >dp reset the dp
tcd
txa return the status
rtl
lenv anop local copy of *env
stackPtr ds 2
dp ds 2
ret ds 4
end