firmware/target/arm/system-arm.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Thom Johansen
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "config.h"
  22 #include "system.h"
  23 #include <stdio.h>
  24 #include "lcd.h"
  25 #include "font.h"
  26 #include "gcc_extensions.h"
  27
  28 #include <get_sp.h>
  29 #include <backtrace.h>
  30
  31 static const char* const uiename[] = {
  32     "Undefined instruction",
  33     "Prefetch abort",
  34     "Data abort",
  35     "Divide by zero",
  36     "SWI"
  37 };
  38
  39 void __attribute__((weak,naked)) data_abort_handler(void)
  40 {
  41     asm volatile(
  42         "sub    r0, lr, #8  \n"
  43         "mov    r1, #2      \n"
  44         "b      UIE         \n"
  45         );
  46 }
  47
  48 void __attribute__((weak,naked)) software_int_handler(void)
  49 {
  50     asm volatile(
  51         "sub    r0, lr, #4  \n"
  52         "mov    r1, #4      \n"
  53         "b      UIE         \n"
  54         );
  55 }
  56
  57 void __attribute__((weak,naked)) reserved_handler(void)
  58 {
  59     asm volatile(
  60         "sub    r0, lr, #4  \n"
  61         "mov    r1, #4      \n"
  62         "b      UIE         \n"
  63         );
  64 }
  65
  66 void __attribute__((weak,naked)) prefetch_abort_handler(void)
  67 {
  68     asm volatile(
  69         "sub    r0, lr, #4  \n"
  70         "mov    r1, #1      \n"
  71         "b      UIE         \n"
  72         );
  73 }
  74
  75 void __attribute__((weak,naked)) undef_instr_handler(void)
  76 {
  77     asm volatile(
  78         "sub    r0, lr, #4    \n"
  79 #ifdef USE_THUMB
  80         "mrs    r1, spsr      \n"
  81         "tst    r1, #(1 << 5) \n" // T bit set ?
  82         "subne  r0, lr, #2    \n" // if yes, offset to THUMB instruction
  83 #endif
  84         "mov    r1, #0        \n"
  85         "b      UIE           \n"
  86         );
  87 }
  88
  89 /* Unexpected Interrupt or Exception handler. Currently only deals with
  90    exceptions, but will deal with interrupts later.
  91  */
  92 void NORETURN_ATTR UIE(unsigned int pc, unsigned int num)
  93 {
  94     /* safe guard variable - we call backtrace() only on first
  95      * UIE call. This prevent endless loop if backtrace() touches
  96      * memory regions which cause abort
  97      */
  98     static bool triggered = false;
  99
 100 #if LCD_DEPTH > 1
 101     lcd_set_backdrop(NULL);
 102     lcd_set_drawmode(DRMODE_SOLID);
 103     lcd_set_foreground(LCD_BLACK);
 104     lcd_set_background(LCD_WHITE);
 105 #endif
 106     unsigned line = 0;
 107
 108     lcd_setfont(FONT_SYSFIXED);
 109     lcd_set_viewport(NULL);
 110     lcd_clear_display();
 111     lcd_putsf(0, line++, "%s at %08x" IF_COP(" (%d)"), uiename[num], pc IF_COP(, CURRENT_CORE));
 112
 113 #if !defined(CPU_ARM7TDMI) && (CONFIG_CPU != RK27XX) /* arm7tdmi has no MPU/MMU */
 114     if(num == 1 || num == 2) /* prefetch / data abort */
 115     {
 116         register unsigned status;
 117
 118 #if ARM_ARCH >= 6
 119         /* ARMv6 has 2 different registers for prefetch & data aborts */
 120         if(num == 1)    /* instruction prefetch abort */
 121             asm volatile( "mrc p15, 0, %0, c5, c0, 1\n" : "=r"(status));
 122         else
 123 #endif
 124             asm volatile( "mrc p15, 0, %0, c5, c0, 0\n" : "=r"(status));
 125
 126         lcd_putsf(0, line++, "FSR 0x%x", status);
 127
 128         unsigned int domain = (status >> 4) & 0xf;
 129         unsigned int fault = status & 0xf;
 130 #if ARM_ARCH >= 6
 131         fault |= (status & (1<<10)) >> 6; /* fault is 5 bits on armv6 */
 132 #endif
 133         lcd_putsf(0, line++, "(domain %d, fault %d)", domain, fault);
 134
 135         if(num == 2) /* data abort */
 136         {
 137             register unsigned address;
 138             /* read FAR (fault address register) */
 139             asm volatile( "mrc p15, 0, %0, c6, c0\n" : "=r"(address));
 140             lcd_putsf(0, line++, "address 0x%8x", address);
 141 #if ARM_ARCH >= 6
 142             lcd_putsf(0, line++, (status & (1<<11)) ? "(write)" : "(read)");
 143 #endif
 144         }
 145     }   /* num == 1 || num == 2 // prefetch/data abort */
 146 #endif /* !defined(CPU_ARM7TDMI */
 147
 148     if (!triggered)
 149     {
 150         triggered = true;
 151         backtrace(pc, __get_sp(), &line);
 152     }
 153
 154     lcd_update();
 155
 156     disable_interrupt(IRQ_FIQ_STATUS);
 157
 158     system_exception_wait(); /* If this returns, try to reboot */
 159     system_reboot();
 160     while (1);       /* halt */
 161 }
 162
 163 /* Needs to be here or gcc won't find it */
 164 void __attribute__((naked)) __div0(void)
 165 {
 166     asm volatile (
 167         "ldr    r0, [sp]    \r\n"
 168         "sub    r0, r0, #4  \r\n"
 169         "mov    r1, #3      \r\n"
 170         "b      UIE         \r\n"
 171     );
 172 }