exception.c

   1 /*
   2         BootMii - a Free Software replacement for the Nintendo/BroadOn bootloader.
   3         Requires mini.
   4
   5 Copyright (C) 2008              Segher Boessenkool <segher@kernel.crashing.org>
   6
   7 # This code is licensed to you under the terms of the GNU GPL, version 2;
   8 # see file COPYING or http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
   9 */
  10
  11 #include "bootmii_ppc.h"
  12
  13 #include "string.h"
  14 #include "irq.h"
  15 #include "hollywood.h"
  16
  17 extern char exception_2200_start, exception_2200_end;
  18
  19 void exception_handler(int exception)
  20 {
  21         // check if the exception was actually an external interrupt
  22         if (exception == 0x500) {
  23                 u32 cookie = irq_kill();
  24                 irq_handler();
  25                 irq_restore(cookie);
  26                 //_CPU_ISR_Enable(); //wtf
  27         }
  28
  29         // check if exception happened due to the decrementer
  30         else if (exception == 0x900) {
  31                 printf("\nDecrementer exception occured - who cares?\n");
  32         }
  33
  34         else {
  35                 u32 *x;
  36                 u32 i;
  37
  38                 printf("\nException %04X occurred!\n", exception);
  39
  40                 x = (u32 *)0x80002000;
  41
  42                 printf("\n R0..R7    R8..R15  R16..R23  R24..R31\n");
  43                 for (i = 0; i < 8; i++) {
  44                         printf("%08x  %08x  %08x  %08x\n", x[0], x[8], x[16], x[24]);
  45                         x++;
  46                 }
  47                 x = (u32 *)0x80002080;
  48
  49                 printf("\n CR/XER    LR/CTR  SRR0/SRR1 DAR/DSISR\n");
  50                 for (i = 0; i < 2; i++) {
  51                         printf("%08x  %08x  %08x  %08x\n", x[0], x[2], x[4], x[6]);
  52                         x++;
  53                 }
  54
  55                 // Hang.
  56                 for (;;)
  57                         ;
  58         }
  59 }
  60
  61 void exception_init(void)
  62 {
  63         u32 vector;
  64         u32 len_2200;
  65
  66         for (vector = 0x100; vector < 0x2000; vector += 0x10) {
  67                 u32 *insn = (u32 *)(0x80000000 + vector);
  68
  69                 insn[0] = 0xbc002000;                   // stmw 0,0x2000(0)
  70                 insn[1] = 0x38600000 | (u32)vector;     // li 3,vector
  71                 insn[2] = 0x48002202;                   // ba 0x2200
  72                 insn[3] = 0;
  73         }
  74         sync_before_exec((void *)0x80000100, 0x1f00);
  75
  76         len_2200 = &exception_2200_end - &exception_2200_start;
  77         memcpy((void *)0x80002200, &exception_2200_start, len_2200);
  78         sync_before_exec((void *)0x80002200, len_2200);
  79 }
  80