osfmk/kdp/ml/ppc/kdp_asm.s

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 #include <mach_kdb.h>
  31 #include <mach_kgdb.h>
  32 #include <mach_debug.h>
  33 #include <assym.s>
  34 #include <ppc/asm.h>
  35 #include <ppc/proc_reg.h>
  36 #include <mach/ppc/vm_param.h>
  37
  38 /* void kdp_call_with_ctx(int type, struct ppc_thread_state *ssp)
  39  *
  40  * Switch on kdp stack and  enter the debugger. On return,
  41  * switch back to the previous stack
  42  *
  43  * If the kdp stack is not free, we allocate ourselves a frame below
  44  * the current kdp frame. This should never occur in a perfect world.
  45  */
  46
  47 ENTRY(kdp_call_with_ctx, TAG_NO_FRAME_USED)
  48
  49         lis             r2,hi16(MASK(MSR_VEC))  ; Get the vector enable
  50         mfmsr   r7                                      ; Get the MSR
  51         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  52         mflr    r0
  53         andc    r7,r7,r2                        ; Clear FP, VEC, and EE
  54         mtmsr   r7
  55         isync                                                                           ; Need this because we may have ditched fp/vec
  56         mfsprg  r8,0                            /* Get the per_proc block address */
  57         stw     r0,     FM_LR_SAVE(r1)          /* save lr in the current frame */
  58
  59         lwz     r9,     PP_DEBSTACKPTR(r8)      /* get kdp stack pointer */
  60         cmpwi   r9,     0
  61         bne     0f
  62
  63 #ifdef  LET_KDP_REENTER
  64         mr      r9,     r1                      /* get current stack pointer */
  65         subi    r9,     r9,     FM_REDZONE + FM_SIZE
  66 #else
  67         bl      EXT(kdp_print_backtrace)
  68 #endif
  69
  70 0:
  71         stw     r1,     FM_ARG0(r9)                     /* Store old stack pointer */
  72         li      r0,     0
  73         stw     r0,     PP_DEBSTACKPTR(r8)      /* Mark kdp stack as busy */
  74
  75         subi    r1,     r9,     FM_SIZE
  76         stw     r0,     FM_BACKPTR(r1)
  77
  78         bl      EXT(kdp_trap)
  79
  80         lis             r2,hi16(MASK(MSR_VEC))          ; Get the vector enable
  81         mfmsr   r0                                      /* Get the MSR */
  82         ori             r2,r2,lo16(MASK(MSR_EE)|MASK(MSR_FP))   ; Get FP and EE
  83         addi    r1,     r1,     FM_SIZE
  84         andc    r0,r0,r2                        ; Clear FP, VEC, and EE
  85         mtmsr   r0
  86         isync                                           ; Need this because we may have ditched fp/vec
  87
  88         mfsprg  r8,0                            /* Get the per_proc block address */
  89
  90         stw     r1,     PP_DEBSTACKPTR(r8)      /* Mark gdb stack as free */
  91         lwz     r1,     FM_ARG0(r1)
  92         lwz     r0,     FM_LR_SAVE(r1)
  93         mtlr    r0
  94
  95         blr
  96
  97