osfmk/kdp/ml/ppc/kdp_asm.s

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 #include <mach_kdb.h>
  23 #include <mach_kgdb.h>
  24 #include <mach_debug.h>
  25 #include <assym.s>
  26 #include <ppc/asm.h>
  27 #include <ppc/proc_reg.h>
  28 #include <mach/ppc/vm_param.h>
  29
  30 /* void kdp_call_with_ctx(int type, struct ppc_thread_state *ssp)
  31  *
  32  * Switch on kdp stack and  enter the debugger. On return,
  33  * switch back to the previous stack
  34  *
  35  * If the kdp stack is not free, we allocate ourselves a frame below
  36  * the current kdp frame. This should never occur in a perfect world.
  37  */
  38
  39 ENTRY(kdp_call_with_ctx, TAG_NO_FRAME_USED)
  40
  41         lis             r2,hi16(MASK(MSR_VEC))  ; Get the vector enable
  42         mfmsr   r7                                      ; Get the MSR
  43         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  44         mflr    r0
  45         andc    r7,r7,r2                        ; Clear FP, VEC, and EE
  46         mtmsr   r7
  47         isync                                                                           ; Need this because we may have ditched fp/vec
  48         mfsprg  r8,0                            /* Get the per_proc block address */
  49         stw     r0,     FM_LR_SAVE(r1)          /* save lr in the current frame */
  50
  51         lwz     r9,     PP_DEBSTACKPTR(r8)      /* get kdp stack pointer */
  52         cmpwi   r9,     0
  53         bne     0f
  54
  55 #ifdef  LET_KDP_REENTER
  56         mr      r9,     r1                      /* get current stack pointer */
  57         subi    r9,     r9,     FM_REDZONE + FM_SIZE
  58 #else
  59         bl      EXT(kdp_print_backtrace)
  60 #endif
  61
  62 0:
  63         stw     r1,     FM_ARG0(r9)                     /* Store old stack pointer */
  64         li      r0,     0
  65         stw     r0,     PP_DEBSTACKPTR(r8)      /* Mark kdp stack as busy */
  66
  67         subi    r1,     r9,     FM_SIZE
  68         stw     r0,     FM_BACKPTR(r1)
  69
  70         bl      EXT(kdp_trap)
  71
  72         lis             r2,hi16(MASK(MSR_VEC))          ; Get the vector enable
  73         mfmsr   r0                                      /* Get the MSR */
  74         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  75         addi    r1,     r1,     FM_SIZE
  76         andc    r0,r0,r2                        ; Clear FP, VEC, and EE
  77         mtmsr   r0
  78         isync                                           ; Need this because we may have ditched fp/vec
  79
  80         mfsprg  r8,0                            /* Get the per_proc block address */
  81
  82         stw     r1,     PP_DEBSTACKPTR(r8)      /* Mark gdb stack as free */
  83         lwz     r1,     FM_ARG0(r1)
  84         lwz     r0,     FM_LR_SAVE(r1)
  85         mtlr    r0
  86
  87         blr
  88
  89