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  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 #include <mach_kdb.h>
  26 #include <mach_kgdb.h>
  27 #include <mach_debug.h>
  28 #include <assym.s>
  29 #include <ppc/asm.h>
  30 #include <ppc/proc_reg.h>
  31 #include <mach/ppc/vm_param.h>
  32
  33 /* void kdp_call_with_ctx(int type, struct ppc_thread_state *ssp)
  34  *
  35  * Switch on kdp stack and  enter the debugger. On return,
  36  * switch back to the previous stack
  37  *
  38  * If the kdp stack is not free, we allocate ourselves a frame below
  39  * the current kdp frame. This should never occur in a perfect world.
  40  */
  41
  42 ENTRY(kdp_call_with_ctx, TAG_NO_FRAME_USED)
  43
  44         lis             r2,hi16(MASK(MSR_VEC))  ; Get the vector enable
  45         mfmsr   r7                                      ; Get the MSR
  46         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  47         mflr    r0
  48         andc    r7,r7,r2                        ; Clear FP, VEC, and EE
  49         mtmsr   r7
  50         isync                                                                           ; Need this because we may have ditched fp/vec
  51         mfsprg  r8,0                            /* Get the per_proc block address */
  52         stw     r0,     FM_LR_SAVE(r1)          /* save lr in the current frame */
  53
  54         lwz     r9,     PP_DEBSTACKPTR(r8)      /* get kdp stack pointer */
  55         cmpwi   r9,     0
  56         bne     0f
  57
  58 #ifdef  LET_KDP_REENTER
  59         mr      r9,     r1                      /* get current stack pointer */
  60         subi    r9,     r9,     FM_REDZONE + FM_SIZE
  61 #else
  62         bl      EXT(kdp_print_backtrace)
  63 #endif
  64
  65 0:
  66         stw     r1,     FM_ARG0(r9)                     /* Store old stack pointer */
  67         li      r0,     0
  68         stw     r0,     PP_DEBSTACKPTR(r8)      /* Mark kdp stack as busy */
  69
  70         subi    r1,     r9,     FM_SIZE
  71         stw     r0,     FM_BACKPTR(r1)
  72
  73         bl      EXT(kdp_trap)
  74
  75         lis             r2,hi16(MASK(MSR_VEC))          ; Get the vector enable
  76         mfmsr   r0                                      /* Get the MSR */
  77         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  78         addi    r1,     r1,     FM_SIZE
  79         andc    r0,r0,r2                        ; Clear FP, VEC, and EE
  80         mtmsr   r0
  81         isync                                           ; Need this because we may have ditched fp/vec
  82
  83         mfsprg  r8,0                            /* Get the per_proc block address */
  84
  85         stw     r1,     PP_DEBSTACKPTR(r8)      /* Mark gdb stack as free */
  86         lwz     r1,     FM_ARG0(r1)
  87         lwz     r0,     FM_LR_SAVE(r1)
  88         mtlr    r0
  89
  90         blr
  91
  92