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         mfmsr   r7                                      /* Get the MSR */
  42         mflr    r0
  43         rlwinm  r7,r7,0,MSR_EE_BIT+1,MSR_EE_BIT-1       /* Turn off interruptions enable bit */
  44         mtmsr   r7
  45         mfsprg  r8,0                            /* Get the per_proc block address */
  46         stw     r0,     FM_LR_SAVE(r1)          /* save lr in the current frame */
  47
  48         lwz     r9,     PP_DEBSTACKPTR(r8)      /* get kdp stack pointer */
  49         cmpwi   r9,     0
  50         bne     0f
  51
  52 #ifdef  LET_KDP_REENTER
  53         mr      r9,     r1                      /* get current stack pointer */
  54         subi    r9,     r9,     FM_REDZONE + SS_SIZE
  55 #else
  56         bl      EXT(kdp_print_backtrace)
  57 #endif
  58
  59 0:
  60         stw     r1,     FM_ARG0(r9)                     /* Store old stack pointer */
  61         li      r0,     0
  62         stw     r0,     PP_DEBSTACKPTR(r8)      /* Mark kdp stack as busy */
  63
  64         subi    r1,     r9,     FM_SIZE
  65         stw     r0,     FM_BACKPTR(r1)
  66
  67         bl      EXT(kdp_trap)
  68
  69         mfmsr   r0                                      /* Get the MSR */
  70         addi    r1,     r1,     FM_SIZE
  71         rlwinm  r0,r0,0,MSR_EE_BIT+1,MSR_EE_BIT-1       /* Turn off interruptions enable bit */
  72         mtmsr   r0
  73
  74         mfsprg  r8,0                            /* Get the per_proc block address */
  75
  76         stw     r1,     PP_DEBSTACKPTR(r8)      /* Mark gdb stack as free */
  77         lwz     r1,     FM_ARG0(r1)
  78         lwz     r0,     FM_LR_SAVE(r1)
  79         mtlr    r0
  80
  81         blr
  82
  83