cpu/mpc8xx/bedbug_860.c

   1 /*
   2  * Bedbug Functions specific to the MPC860 chip
   3  */
   4
   5 #include <common.h>
   6 #include <command.h>
   7 #include <linux/ctype.h>
   8 #include <bedbug/bedbug.h>
   9 #include <bedbug/regs.h>
  10 #include <bedbug/ppc.h>
  11 #include <bedbug/type.h>
  12
  13 #if defined(CONFIG_CMD_BEDBUG) && defined(CONFIG_8xx)
  14
  15 #define MAX_BREAK_POINTS 2
  16
  17 extern CPU_DEBUG_CTX bug_ctx;
  18
  19 void bedbug860_init __P((void));
  20 void bedbug860_do_break __P((cmd_tbl_t*,int,int,char*[]));
  21 void bedbug860_break_isr __P((struct pt_regs*));
  22 int  bedbug860_find_empty __P((void));
  23 int  bedbug860_set __P((int,unsigned long));
  24 int  bedbug860_clear __P((int));
  25
  26 \f
  27 /* ======================================================================
  28  * Initialize the global bug_ctx structure for the MPC860.  Clear all
  29  * of the breakpoints.
  30  * ====================================================================== */
  31
  32 void bedbug860_init( void )
  33 {
  34   int   i;
  35   /* -------------------------------------------------- */
  36
  37   bug_ctx.hw_debug_enabled = 0;
  38   bug_ctx.stopped = 0;
  39   bug_ctx.current_bp = 0;
  40   bug_ctx.regs = NULL;
  41
  42   bug_ctx.do_break   = bedbug860_do_break;
  43   bug_ctx.break_isr  = bedbug860_break_isr;
  44   bug_ctx.find_empty = bedbug860_find_empty;
  45   bug_ctx.set        = bedbug860_set;
  46   bug_ctx.clear      = bedbug860_clear;
  47
  48   for( i = 1; i <= MAX_BREAK_POINTS; ++i )
  49     (*bug_ctx.clear)( i );
  50
  51   puts ("BEDBUG:ready\n");
  52   return;
  53 } /* bedbug_init_breakpoints */
  54
  55
  56 \f
  57 /* ======================================================================
  58  * Set/clear/show one of the hardware breakpoints for the 860.  The "off"
  59  * string will disable a specific breakpoint.  The "show" string will
  60  * display the current breakpoints.  Otherwise an address will set a
  61  * breakpoint at that address.  Setting a breakpoint uses the CPU-specific
  62  * set routine which will assign a breakpoint number.
  63  * ====================================================================== */
  64
  65 void bedbug860_do_break (cmd_tbl_t *cmdtp, int flag, int argc,
  66                          char *argv[])
  67 {
  68   long          addr = 0;       /* Address to break at  */
  69   int           which_bp;       /* Breakpoint number    */
  70   /* -------------------------------------------------- */
  71
  72   if (argc < 2)
  73   {
  74     printf ("Usage:\n%s\n", cmdtp->usage);
  75     return;
  76   }
  77
  78   /* Turn off a breakpoint */
  79
  80   if( strcmp( argv[ 1 ], "off" ) == 0 )
  81   {
  82     if( bug_ctx.hw_debug_enabled == 0 )
  83     {
  84       printf( "No breakpoints enabled\n" );
  85       return;
  86     }
  87
  88     which_bp = simple_strtoul( argv[ 2 ], NULL, 10 );
  89
  90     if( bug_ctx.clear )
  91       (*bug_ctx.clear)( which_bp );
  92
  93     printf( "Breakpoint %d removed\n", which_bp );
  94     return;
  95   }
  96
  97   /* Show a list of breakpoints */
  98
  99   if( strcmp( argv[ 1 ], "show" ) == 0 )
 100   {
 101     for( which_bp = 1; which_bp <= MAX_BREAK_POINTS; ++which_bp )
 102     {
 103
 104       switch( which_bp )
 105       {
 106       case 1: addr = GET_CMPA(); break;
 107       case 2: addr = GET_CMPB(); break;
 108       case 3: addr = GET_CMPC(); break;
 109       case 4: addr = GET_CMPD(); break;
 110       }
 111
 112       printf( "Breakpoint [%d]: ", which_bp );
 113       if( addr == 0 )
 114         printf( "NOT SET\n" );
 115       else
 116         disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX );
 117     }
 118     return;
 119   }
 120
 121   /* Set a breakpoint at the address */
 122
 123   if( !isdigit( argv[ 1 ][ 0 ]))
 124   {
 125     printf ("Usage:\n%s\n", cmdtp->usage);
 126     return;
 127   }
 128
 129   addr = simple_strtoul( argv[ 1 ], NULL, 16 ) & 0xfffffffc;
 130
 131   if(( bug_ctx.set ) && ( which_bp = (*bug_ctx.set)( 0, addr )) > 0 )
 132   {
 133     printf( "Breakpoint [%d]: ", which_bp );
 134     disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX );
 135   }
 136
 137   return;
 138 } /* bedbug860_do_break */
 139
 140
 141 \f
 142 /* ======================================================================
 143  * Handle a breakpoint.  First determine which breakpoint was hit by
 144  * looking at the DeBug Status Register (DBSR), clear the breakpoint
 145  * and enter a mini main loop.  Stay in the loop until the stopped flag
 146  * in the debug context is cleared.
 147  * ====================================================================== */
 148
 149 void bedbug860_break_isr( struct pt_regs *regs )
 150 {
 151   unsigned long addr;     /* Address stopped at   */
 152   unsigned long cause;     /* Address stopped at   */
 153   /* -------------------------------------------------- */
 154
 155   cause = GET_ICR();
 156
 157   if( !(cause & 0x00000004)) {
 158     printf( "Not an instruction breakpoint (ICR 0x%08lx)\n", cause );
 159     return;
 160   }
 161
 162   addr = regs->nip;
 163
 164   if( addr == GET_CMPA() )
 165   {
 166     bug_ctx.current_bp = 1;
 167   }
 168   else if( addr == GET_CMPB() )
 169   {
 170     bug_ctx.current_bp = 2;
 171   }
 172   else if( addr == GET_CMPC() )
 173   {
 174     bug_ctx.current_bp = 3;
 175   }
 176   else if( addr == GET_CMPD() )
 177   {
 178     bug_ctx.current_bp = 4;
 179   }
 180
 181   bedbug_main_loop( addr, regs );
 182   return;
 183 } /* bedbug860_break_isr */
 184
 185
 186 \f
 187 /* ======================================================================
 188  * Look through all of the hardware breakpoints available to see if one
 189  * is unused.
 190  * ====================================================================== */
 191
 192 int bedbug860_find_empty( void )
 193 {
 194   /* -------------------------------------------------- */
 195
 196   if( GET_CMPA() == 0 )
 197     return 1;
 198
 199   if( GET_CMPB() == 0 )
 200     return 2;
 201
 202   if( GET_CMPC() == 0 )
 203     return 3;
 204
 205   if( GET_CMPD() == 0 )
 206     return 4;
 207
 208   return 0;
 209 } /* bedbug860_find_empty */
 210
 211
 212 \f
 213 /* ======================================================================
 214  * Set a breakpoint.  If 'which_bp' is zero then find an unused breakpoint
 215  * number, otherwise reassign the given breakpoint.  If hardware debugging
 216  * is not enabled, then turn it on via the MSR and DBCR0.  Set the break
 217  * address in the appropriate IACx register and enable proper address
 218  * beakpoint in DBCR0.
 219  * ====================================================================== */
 220
 221 int bedbug860_set( int which_bp, unsigned long addr )
 222 {
 223   /* -------------------------------------------------- */
 224
 225   /* Only look if which_bp == 0, else use which_bp */
 226   if(( bug_ctx.find_empty ) && ( !which_bp ) &&
 227      ( which_bp = (*bug_ctx.find_empty)()) == 0 )
 228   {
 229     printf( "All breakpoints in use\n" );
 230     return 0;
 231   }
 232
 233   if( which_bp < 1 || which_bp > MAX_BREAK_POINTS )
 234   {
 235     printf( "Invalid break point # %d\n", which_bp );
 236     return 0;
 237   }
 238
 239   if( ! bug_ctx.hw_debug_enabled )
 240   {
 241     bug_ctx.hw_debug_enabled = 1;
 242     SET_DER( GET_DER() | 0x00000004 );
 243   }
 244
 245   switch( which_bp )
 246   {
 247   case 1:
 248     SET_CMPA( addr );
 249     SET_ICTRL( GET_ICTRL() | 0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */
 250     break;
 251
 252   case 2:
 253     SET_CMPB( addr );
 254     SET_ICTRL( GET_ICTRL() | 0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */
 255     break;
 256
 257   case 3:
 258     SET_CMPC( addr );
 259     SET_ICTRL( GET_ICTRL() | 0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */
 260     break;
 261
 262   case 4:
 263     SET_CMPD( addr );
 264     SET_ICTRL( GET_ICTRL() | 0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */
 265     break;
 266   }
 267
 268   return which_bp;
 269 } /* bedbug860_set */
 270
 271
 272 \f
 273 /* ======================================================================
 274  * Disable a specific breakoint by setting the appropriate IACx register
 275  * to zero and claring the instruction address breakpoint in DBCR0.
 276  * ====================================================================== */
 277
 278 int bedbug860_clear( int which_bp )
 279 {
 280   /* -------------------------------------------------- */
 281
 282   if( which_bp < 1 || which_bp > MAX_BREAK_POINTS )
 283   {
 284     printf( "Invalid break point # (%d)\n", which_bp );
 285     return -1;
 286   }
 287
 288   switch( which_bp )
 289   {
 290   case 1:
 291     SET_CMPA( 0 );
 292     SET_ICTRL( GET_ICTRL() & ~0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */
 293     break;
 294
 295   case 2:
 296     SET_CMPB( 0 );
 297     SET_ICTRL( GET_ICTRL() & ~0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */
 298     break;
 299
 300   case 3:
 301     SET_CMPC( 0 );
 302     SET_ICTRL( GET_ICTRL() & ~0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */
 303     break;
 304
 305   case 4:
 306     SET_CMPD( 0 );
 307     SET_ICTRL( GET_ICTRL() & ~0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */
 308     break;
 309   }
 310
 311   return 0;
 312 } /* bedbug860_clear */
 313
 314
 315 /* ====================================================================== */
 316 #endif