osfmk/kdp/ml/ppc/kdp_asm.s

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #include <mach_kdb.h>
  29 #include <mach_kgdb.h>
  30 #include <mach_debug.h>
  31 #include <assym.s>
  32 #include <ppc/asm.h>
  33 #include <ppc/proc_reg.h>
  34 #include <mach/ppc/vm_param.h>
  35
  36 /* void kdp_call_with_ctx(int type, struct ppc_thread_state *ssp)
  37  *
  38  * Switch on kdp stack and  enter the debugger. On return,
  39  * switch back to the previous stack
  40  *
  41  * If the kdp stack is not free, we allocate ourselves a frame below
  42  * the current kdp frame. This should never occur in a perfect world.
  43  */
  44
  45 ENTRY(kdp_call_with_ctx, TAG_NO_FRAME_USED)
  46
  47         lis             r2,hi16(MASK(MSR_VEC))  ; Get the vector enable
  48         mfmsr   r7                                      ; Get the MSR
  49         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  50         mflr    r0
  51         andc    r7,r7,r2                        ; Clear FP, VEC, and EE
  52         mtmsr   r7
  53         isync                                                                           ; Need this because we may have ditched fp/vec
  54         mfsprg  r8,0                            /* Get the per_proc block address */
  55         stw     r0,     FM_LR_SAVE(r1)          /* save lr in the current frame */
  56
  57         lwz     r9,     PP_DEBSTACKPTR(r8)      /* get kdp stack pointer */
  58         cmpwi   r9,     0
  59         bne     0f
  60
  61 #ifdef  LET_KDP_REENTER
  62         mr      r9,     r1                      /* get current stack pointer */
  63         subi    r9,     r9,     FM_REDZONE + FM_SIZE
  64 #else
  65         bl      EXT(kdp_print_backtrace)
  66 #endif
  67
  68 0:
  69         stw     r1,     FM_ARG0(r9)                     /* Store old stack pointer */
  70         li      r0,     0
  71         stw     r0,     PP_DEBSTACKPTR(r8)      /* Mark kdp stack as busy */
  72
  73         subi    r1,     r9,     FM_SIZE
  74         stw     r0,     FM_BACKPTR(r1)
  75
  76         bl      EXT(kdp_trap)
  77
  78         lis             r2,hi16(MASK(MSR_VEC))          ; Get the vector enable
  79         mfmsr   r0                                      /* Get the MSR */
  80         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  81         addi    r1,     r1,     FM_SIZE
  82         andc    r0,r0,r2                        ; Clear FP, VEC, and EE
  83         mtmsr   r0
  84         isync                                           ; Need this because we may have ditched fp/vec
  85
  86         mfsprg  r8,0                            /* Get the per_proc block address */
  87
  88         stw     r1,     PP_DEBSTACKPTR(r8)      /* Mark gdb stack as free */
  89         lwz     r1,     FM_ARG0(r1)
  90         lwz     r0,     FM_LR_SAVE(r1)
  91         mtlr    r0
  92
  93         blr
  94
  95