398 lines
14 KiB
ArmAsm
398 lines
14 KiB
ArmAsm
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/*
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* mvme135-asm.S -- assembler routines for the MVME stub.
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*
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* This code was pulled out of mvme135-stub.c by Ian Taylor so that I
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* could handle different register and label prefixes in a sensible
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* way.
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*/
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/****************************************************************************
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THIS SOFTWARE IS NOT COPYRIGHTED
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HP offers the following for use in the public domain. HP makes no
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warranty with regard to the software or it's performance and the
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user accepts the software "AS IS" with all faults.
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HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
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TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/
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#include "asm.h"
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.title "mvme135-asm.S for m68k"
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.globl SYM (registers)
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.globl SYM (lastFrame)
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.globl SYM (superStack)
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.globl SYM (exceptionHook)
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.globl SYM (_returnFromException)
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.globl SYM (stackPtr)
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.globl SYM (handle_exception)
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.globl SYM (exceptionSize)
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.globl SYM (exceptionHandler)
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.text
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/*
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* Create a new exception vector table and populates it. Vectors from the
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* boot monitor are spliced in so I/O and the abort button will continue
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* to work. We also use the monitor's generalized vector for anything the
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* debugger doesn't want.
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*/
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.global SYM (setup_vectors)
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SYM (setup_vectors):
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link fp, IMM (-8)
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/* copy monitor vector table */
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movecl vbr, a0
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lea SYM (vbr_table), a1
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movel 0x8(a0), d0 /* get generalized vector */
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movew IMM (0x3fc), d1 /* load vector count */
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loop: /* fill table to gen. vector */
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movel d0, (a1,d1)
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subqw IMM (4), d1
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bne loop
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movel 0x10(a0), 0x10(a1) /* breakpoint */
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movel 0x24(a0), 0x24(a1) /* trace */
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movel 0xbc(a0), 0xbc(a1) /* system call */
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/* add stub vectors to table */
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movel SYM (_catchException), 0x8(a1) /* vector = 2, Access Fault */
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movel SYM (_catchException), 0xc(a1) /* vector = 3, Address Error */
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movel SYM (_catchException), 0x10(a1) /* vector = 4, Illegal instruction */
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movel SYM (_catchException), 0x14(a1) /* vector = 5, divide by 0 */
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movel SYM (_catchException), 0x18(a1) /* vector = 6, chk, chk2 instruction */
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movel SYM (_catchException), 0x1c(a1) /* vector = 7, ftrap, trap, trapv ins */
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movel SYM (_catchException), 0x20(a1) /* vector = 8, priviledge violation */
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movel SYM (_catchException), 0x24(a1) /* vector = 9, trace */
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movel SYM (_catchException), 0x28(a1) /* vector = 10, Aline opcode */
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movel SYM (_catchException), 0x2c(a1) /* vector = 11, fline opcode */
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movel SYM (_catchException), 0x30(a1) /* vector = 12, reserved */
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movel SYM (_catchException), 0x34(a1) /* vector = 13, coprocessor protocol violation */
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movel SYM (_catchException), 0x38(a1) /* vector = 14, format error */
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movel SYM (_catchException), 0x3c(a1) /* vector = 15, unitialized interupt */
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/* unassigned, reserved */
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movel SYM (_catchException), 0x40(a1) /* vector = 16 */
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movel SYM (_catchException), 0x44(a1) /* vector = 17 */
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movel SYM (_catchException), 0x48(a1) /* vector = 18 */
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movel SYM (_catchException), 0x4c(a1) /* vector = 19 */
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movel SYM (_catchException), 0x50(a1) /* vector = 20 */
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movel SYM (_catchException), 0x54(a1) /* vector = 21 */
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movel SYM (_catchException), 0x58(a1) /* vector = 22 */
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movel SYM (_catchException), 0x5c(a1) /* vector = 23 */
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movel SYM (_catchException), 0x84(a1) /* vector = 33, breakpoint, trap #1 */
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movel SYM (_catchException), 0xa0(a1) /* vector = 40 , trap #8*/
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/* floating point traps */
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movel SYM (_catchException), 0xc0(a1) /* vector = 48 */
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movel SYM (_catchException), 0xc4(a1) /* vector = 49 */
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movel SYM (_catchException), 0xc8(a1) /* vector = 50 */
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movel SYM (_catchException), 0xcc(a1) /* vector = 51 */
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movel SYM (_catchException), 0xd0(a1) /* vector = 52 */
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movel SYM (_catchException), 0xd4(a1) /* vector = 53 */
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movel SYM (_catchException), 0xd8(a1) /* vector = 54 */
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movel SYM (_catchException), 0xdc(a1) /* vector = 55 */
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movel SYM (_catchException), 0xe0(a1) /* vector = 56 */
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movel SYM (_catchException), 0xe4(a1) /* vector = 57 */
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movel SYM (_catchException), 0xe8(a1) /* vector = 58 */
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/*** movel &__debug_level7, 0x7c(a1) /* level7 interupt vector */
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movecl a1, vbr /* change VBR to new table */
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unlk fp
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rts
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/*
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* exceptionHandler -- sets up exception vector table.
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* First arg is an integer vector number
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* Second arg is the function pointer for the vector
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*/
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SYM (exceptionHandler):
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# link a6, IMM (-8)
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#str1: .ascii "Exception Handler Called\n"
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# moveal IMM (str1), a0
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# moveal IMM (str1+25), a1
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# jsr SYM (outln)
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# unlk a6
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rts
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/* this never gets called */
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movel fp@(8), d0 /* get vector number */
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movel fp@(12), a0 /* get function address */
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moveal &SYM (vbr_table), a1 /* FIXME */
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addl d0, d0
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addl d0, d0
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addal d0, a1
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movel a0, (a1)
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movecl a1, vbr
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unlk a6
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rts
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.globl SYM (return_to_super)
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SYM (return_to_super):
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movel SYM (registers)+60,sp /* get new stack pointer */
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movel SYM (lastFrame),a0 /* get last frame info */
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bra return_to_any
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.globl SYM (return_to_user)
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SYM (return_to_user):
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movel SYM (registers)+60,a0 /* get usp */
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movel a0,usp /* set usp */
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movel SYM (superStack),sp /* get original stack pointer */
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return_to_any:
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movel SYM (lastFrame),a0 /* get last frame info */
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movel a0@+,SYM (lastFrame) /* link in previous frame */
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addql IMM (8),a0 /* skip over pc, vector#*/
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movew a0@+,d0 /* get # of words in cpu frame */
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addw d0,a0 /* point to end of data */
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addw d0,a0 /* point to end of data */
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movel a0,a1
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/* copy the stack frame */
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subql IMM (1),d0
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copyUserLoop:
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movew a1@-,sp@-
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dbf d0,copyUserLoop
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#ifdef __HAVE_68881__
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fmoveml SYM (registers)+168,fpcr/fpsr/fpi
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fmovemx SYM (registers)+72,fp0-fp7
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cmpl IMM (-1),a0@ /* skip frestore flag set ? */
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beq skip_frestore
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frestore a0@+
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skip_frestore:
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#endif
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moveml SYM (registers),d0-d7/a0-a6
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rte /* pop and go! */
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/* this function is called immediately when a level 7 interrupt occurs */
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/* if the previous interrupt level was 7 then we're already servicing */
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/* this interrupt and an rte is in order to return to the debugger. */
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/* For the 68000, the offset for sr is 6 due to the jsr return address */
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.text
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.globl SYM (_debug_level7)
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SYM (_debug_level7):
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movew d0,sp@-
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#ifdef mc68020
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movew sp@(2),d0
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#else
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movew sp@(6),d0
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#endif
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andiw IMM (0x700),d0
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cmpiw IMM (0x700),d0
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beq _already7
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movew sp@+,d0
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bra SYM (_catchException)
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_already7:
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movew sp@+,d0
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#ifndef mc68020
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lea sp@(4),sp /* pull off 68000 return address */
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#endif
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rte
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#ifdef mc68020
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/* This function is called when a 68020 exception occurs. It saves
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* all the cpu and fpcp regs in the _registers array, creates a frame on a
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* linked list of frames which has the cpu and fpcp stack frames needed
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* to properly restore the context of these processors, and invokes
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* an exception handler (remcom_handler).
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*
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* stack on entry: stack on exit:
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* N bytes of junk exception # MSWord
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* Exception Format Word exception # MSWord
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* Program counter LSWord
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* Program counter MSWord
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* Status Register
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*
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*
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*/
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.text
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.globl SYM (_catchException)
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SYM (_catchException):
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oriw IMM (0x0700),sr /* Disable interrupts */
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moveml d0-d7/a0-a6,SYM (registers) /* save registers */
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movel SYM (lastFrame),a0 /* last frame pointer */
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#ifdef __HAVE_68881__
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/* do an fsave, then remember the address to begin a restore from */
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fsave a0@-
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fmovemx fp0-fp7, SYM (registers)+72
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fmoveml fpcr/fpsr/fpi, SYM (registers)+168
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#endif
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lea SYM (registers),a5 /* get address of registers */
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movew sp@,d1 /* get status register */
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movew d1,a5@(66) /* save sr */
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movel sp@(2),a4 /* save pc in a4 for later use */
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movel a4,a5@(68) /* save pc in _regisers[] */
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/* figure out how many bytes in the stack frame */
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movew sp@(6),d0 /* get '020 exception format */
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movew d0,d2 /* make a copy of format word */
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andiw IMM (0xf000),d0 /* mask off format type */
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rolw IMM (5),d0 /* rotate into the low byte *2 */
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lea SYM (exceptionSize),a1
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addw d0,a1 /* index into the table */
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movew a1@,d0 /* get number of words in frame */
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movew d0,d3 /* save it */
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subw d0,a0 /* adjust save pointer */
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subw d0,a0 /* adjust save pointer(bytes) */
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movel a0,a1 /* copy save pointer */
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subql IMM (1),d0 /* predecrement loop counter */
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/* copy the frame */
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saveFrameLoop:
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movew sp@+,a1@+
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dbf d0,saveFrameLoop
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/* now that the stack has been clenaed,
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* save the a7 in use at time of exception
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*/
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movel sp,SYM (superStack) /* save supervisor sp */
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andiw IMM (0x2000),d1 /* were we in supervisor mode ? */
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beq userMode
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movel a7,a5@(60) /* save a7 */
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bra a7saveDone
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userMode:
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movel usp,a1
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movel a1,a5@(60) /* save user stack pointer */
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a7saveDone:
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/* save size of frame */
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movew d3,a0@-
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/* compute exception number */
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andl IMM (0xfff),d2 /* mask off vector offset */
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lsrw IMM (2),d2 /* divide by 4 to get vect num */
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movel d2,a0@- /* save it */
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/* save pc causing exception */
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movel a4,a0@-
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/* save old frame link and set the new value*/
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movel SYM (lastFrame),a1 /* last frame pointer */
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movel a1,a0@- /* save pointer to prev frame */
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movel a0,SYM (lastFrame)
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movel d2,sp@- /* push exception num */
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#ifdef TMP_HACK
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movel SYM (exceptionHook),a0 /* get address of handler */
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jbsr a0@ /* and call it */
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#else
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jbsr SYM (remcomHandler)
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#endif
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clrl sp@ /* replace exception num parm with frame ptr */
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jbsr SYM (_returnFromException) /* jbsr, but never returns */
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#else /* mc68000 */
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/* This function is called when an exception occurs. It translates the
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* return address found on the stack into an exception vector # which
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* is then handled by either handle_exception or a system handler.
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* _catchException provides a front end for both.
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*
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* stack on entry: stack on exit:
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* Program counter MSWord exception # MSWord
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* Program counter LSWord exception # MSWord
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* Status Register
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* Return Address MSWord
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* Return Address LSWord
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*/
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.text
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.globl SYM (_catchException)
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SYM (_catchException):
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oriw IMM (0x0700),sr /* Disable interrupts */
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moveml d0-d7/a0-a6,SYM (registers) /* save registers */
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movel SYM (lastFrame),a0 /* last frame pointer */
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#ifdef __HAVE_68881__
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/* do an fsave, then remember the address to begin a restore from */
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fsave a0@-
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fmovemx fp0-fp7, SYM (registers)+72
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fmoveml fpcr/fpsr/fpi, SYM (registers)+168
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#endif
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lea SYM (registers),a5 /* get address of registers */
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movel sp@+,d2 /* pop return address */
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addl IMM (1530),d2 /* convert return addr to */
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divs IMM (6),d2 /* exception number */
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extl d2
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moveql IMM (3),d3 /* assume a three word frame */
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cmpiw IMM (3),d2 /* bus error or address error ? */
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bgt normal /* if >3 then normal error */
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movel sp@+,a0@- /* copy error info to frame buff*/
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movel sp@+,a0@- /* these are never used */
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moveql IMM (7),d3 /* this is a 7 word frame */
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|
normal:
|
||
|
|
movew sp@+,d1 /* pop status register */
|
||
|
|
movel sp@+,a4 /* pop program counter */
|
||
|
|
movew d1,a5@(66) /* save sr */
|
||
|
|
movel a4,a5@(68) /* save pc in _regisers[] */
|
||
|
|
movel a4,a0@- /* copy pc to frame buffer */
|
||
|
|
movew d1,a0@- /* copy sr to frame buffer */
|
||
|
|
|
||
|
|
movel sp,SYM (superStack) /* save supervisor sp */
|
||
|
|
|
||
|
|
andiw IMM (0x2000),d1 /* were we in supervisor mode ? */
|
||
|
|
beq userMode
|
||
|
|
movel a7,a5@(60) /* save a7 */
|
||
|
|
bra saveDone
|
||
|
|
userMode:
|
||
|
|
movel usp,a1 /* save user stack pointer */
|
||
|
|
movel a1,a5@(60) /* save user stack pointer */
|
||
|
|
saveDone:
|
||
|
|
|
||
|
|
movew d3,a0@- /* push frame size in words */
|
||
|
|
movel d2,a0@- /* push vector number */
|
||
|
|
movel a4,a0@- /* push exception pc */
|
||
|
|
|
||
|
|
/* save old frame link and set the new value */
|
||
|
|
movel SYM (lastFrame),a1 /* last frame pointer */
|
||
|
|
movel a1,a0@- /* save pointer to prev frame */
|
||
|
|
movel a0,SYM (lastFrame)
|
||
|
|
|
||
|
|
movel d2,sp@- /* push exception num */
|
||
|
|
movel SYM (exceptionHook),a0 /* get address of handler */
|
||
|
|
jbsr a0@ /* and call it */
|
||
|
|
clrl sp@ /* replace exception num parm with frame ptr */
|
||
|
|
jbsr SYM (_returnFromException) /* jbsr, but never returns */
|
||
|
|
|
||
|
|
#endif /* m68000 */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* remcomHandler is a front end for handle_exception. It moves the
|
||
|
|
* stack pointer into an area reserved for debugger use in case the
|
||
|
|
* breakpoint happened in supervisor mode.
|
||
|
|
*/
|
||
|
|
.globl SYM (remcomHandler)
|
||
|
|
SYM (remcomHandler):
|
||
|
|
addl IMM (4),sp /* pop off return address */
|
||
|
|
movel sp@+,d0 /* get the exception number */
|
||
|
|
movel SYM (stackPtr),sp /* move to remcom stack area */
|
||
|
|
movel d0,sp@- /* push exception onto stack */
|
||
|
|
jbsr SYM (handle_exception) /* this never returns */
|
||
|
|
rts /* return */
|