Retro68/gcc/newlib/libc/machine/rx/setjmp.S
Wolfgang Thaller ec13cc9ce7 fix newlib
2018-12-29 09:59:36 +01:00

90 lines
1.9 KiB
ArmAsm

# setjmp/longjmp for Renesas RX.
#
# The jmpbuf looks like this:
#
# Register jmpbuf offset
# R0 0x0
# R1 0x4
# R2 0x8
# R3 0xc
# R4 0x10
# R5 0x14
# R6 0x18
# R7 0x1c
# R8 0x20
# R9 0x24
# R10 0x28
# R11 0x2c
# R12 0x30
# R13 0x34
# R14 0x38
# R15 0x3c
# PC 0x40
#
# R1 contains the pointer to jmpbuf:
#
# int R1 = setjmp (jmp_buf R1)
# void longjmp (jmp_buf R1, int R2)
#
# The ABI allows for R1-R5 to be clobbered by functions. We must be
# careful to always leave the stack in a usable state in case an
# interrupt happens.
.text
.global _setjmp
.type _setjmp, @function
_setjmp:
mov.l r0, [r1] ; save all the general registers
mov.l r1, 0x4[r1] ; longjmp won't use this, but someone else might.
mov.l r2, 0x8[r1]
mov.l r3, 0xc[r1]
mov.l r4, 0x10[r1]
mov.l r5, 0x14[r1]
mov.l r6, 0x18[r1]
mov.l r7, 0x1c[r1]
mov.l r8, 0x20[r1]
mov.l r9, 0x24[r1]
mov.l r10, 0x28[r1]
mov.l r11, 0x2c[r1]
mov.l r12, 0x30[r1]
mov.l r13, 0x34[r1]
mov.l r14, 0x38[r1]
mov.l r15, 0x3c[r1]
mov.l [r0], r2 ; get return address off the stack
mov.l r2, 0x40[r1] ; PC
mov #0, r1 ; Return 0.
rts
.Lend1:
.size _setjmp, .Lend1 - _setjmp
.global _longjmp
.type _longjmp, @function
_longjmp:
tst r2, r2 ; Set the Z flag if r2 is 0.
stz #1, r2 ; If the Z flag was set put 1 into the return register.
mov r2, 4[r1] ; Put r2 (our return value) into the setjmp buffer as r1.
mov.l [r1], r0 ; Restore the stack - there's a slot for PC
mov.l 0x40[r1], r2 ; Get the saved PC
mov.l r2, [r0] ; Overwrite the old return address
mov.l 0x3c[r1], r15
mov.l 0x38[r1], r14
mov.l 0x34[r1], r13
mov.l 0x30[r1], r12
mov.l 0x2c[r1], r11
mov.l 0x28[r1], r10
mov.l 0x24[r1], r9
mov.l 0x20[r1], r8
mov.l 0x1c[r1], r7
mov.l 0x18[r1], r6
mov.l 0x14[r1], r5
mov.l 0x10[r1], r4
mov.l 0xc[r1], r3
mov.l 0x8[r1], r2
mov.l 0x4[r1], r1 ; This sets up the new return value
rts
.Lend2:
.size _longjmp, .Lend2 - _longjmp