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refactored assembler routines from exceptions.S into mmu.c (access exception handler). Seems to be better, but still hang.

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Markus Fröschle
2014-01-13 19:39:42 +00:00
parent 9b099d935c
commit be94d72097
4 changed files with 23 additions and 34 deletions
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31
sys/exceptions.S
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@@ -391,14 +391,10 @@ reset_vector:
// cannot use the supervisor stack in here. Therefore we first switch to a safe stack
// (RAMBAR0, the processor internal SRAM)
access_exception:
// no point in disabling interrupts within an exception handler
// move.w #0x2700,sr // disable interrupt
// save current SSP
move.l sp,__SUP_SP // defined in linker script: top of SRAM0
lea __SUP_SP - 4,sp // now we can savely use the stack
lea __SUP_SP - 4,sp // now we can savely use this as stack
// save gcc scratch registers, others will be handled by called function
lea -4*4(sp),sp
@@ -407,32 +403,20 @@ access_exception:
move.l __SUP_SP,a0 // original stack pointer
move.l 4(a0),-(sp) // format status word
move.l (a0),-(sp) // program counter at access error
move.l (a0),-(sp) // format status word
move.l 4(a0),-(sp) // program counter at access error
jsr _access_exception
jsr _access_exception // note the undescore
lea 2*4(sp),sp // adjust stack
tst.l d0 // handled?
bne bus_error
beq bus_error // no
movem.l (sp),d0-d1/a0-a1 // restore scratch registers
lea 4*4(sp),sp
move.l (sp)+,a0
move.l (sp)+,d0
move.l __SUP_SP,sp
bra bus_error // everything else is a classic bus error
movem.l (sp),d0-d1/a0-a2 // restore gcc scratch registers
lea 5*4(sp),sp
// revert stack trickery
move.l (sp)+,a0
move.l (sp)+,d0
move.l __SUP_SP,sp
@@ -440,10 +424,11 @@ access_exception:
bus_error:
movem.l (sp),d0-d1/a0-a1 // restore scratch registers
lea 4*4(sp),sp
// revert stack trickery
move.l (sp)+,a0
move.l (sp)+,d0 // restore register
move.l __SUP_SP,sp // restore original stack
bra std_exc_vec