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