cpu/ppc4xx/bedbug_405.c

   1 /*
   2  * Bedbug Functions specific to the PPC405 chip
   3  */
   4
   5 #include <common.h>
   6 #include <command.h>
   7 #include <linux/ctype.h>
   8 #include <bedbug/type.h>
   9 #include <bedbug/bedbug.h>
  10 #include <bedbug/regs.h>
  11 #include <bedbug/ppc.h>
  12
  13 #if defined(CONFIG_CMD_BEDBUG) && defined(CONFIG_4xx)
  14
  15 #define MAX_BREAK_POINTS 4
  16
  17 extern CPU_DEBUG_CTX bug_ctx;
  18
  19 void bedbug405_init __P ((void));
  20 void bedbug405_do_break __P ((cmd_tbl_t *, int, int, char *[]));
  21 void bedbug405_break_isr __P ((struct pt_regs *));
  22 int bedbug405_find_empty __P ((void));
  23 int bedbug405_set __P ((int, unsigned long));
  24 int bedbug405_clear __P ((int));
  25 \f
  26
  27 /* ======================================================================
  28  * Initialize the global bug_ctx structure for the AMCC PPC405. Clear all
  29  * of the breakpoints.
  30  * ====================================================================== */
  31
  32 void bedbug405_init (void)
  33 {
  34         int i;
  35
  36         /* -------------------------------------------------- */
  37
  38         bug_ctx.hw_debug_enabled = 0;
  39         bug_ctx.stopped = 0;
  40         bug_ctx.current_bp = 0;
  41         bug_ctx.regs = NULL;
  42
  43         bug_ctx.do_break = bedbug405_do_break;
  44         bug_ctx.break_isr = bedbug405_break_isr;
  45         bug_ctx.find_empty = bedbug405_find_empty;
  46         bug_ctx.set = bedbug405_set;
  47         bug_ctx.clear = bedbug405_clear;
  48
  49         for (i = 1; i <= MAX_BREAK_POINTS; ++i)
  50                 (*bug_ctx.clear) (i);
  51
  52         puts ("BEDBUG:ready\n");
  53         return;
  54 }       /* bedbug_init_breakpoints */
  55 \f
  56
  57
  58 /* ======================================================================
  59  * Set/clear/show one of the hardware breakpoints for the 405.  The "off"
  60  * string will disable a specific breakpoint.  The "show" string will
  61  * display the current breakpoints.  Otherwise an address will set a
  62  * breakpoint at that address.  Setting a breakpoint uses the CPU-specific
  63  * set routine which will assign a breakpoint number.
  64  * ====================================================================== */
  65
  66 void bedbug405_do_break (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
  67 {
  68         long addr = 0;          /* Address to break at  */
  69         int which_bp;           /* Breakpoint number    */
  70
  71         /* -------------------------------------------------- */
  72
  73         if (argc < 2) {
  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                 if (bug_ctx.hw_debug_enabled == 0) {
  82                         printf ("No breakpoints enabled\n");
  83                         return;
  84                 }
  85
  86                 which_bp = simple_strtoul (argv[2], NULL, 10);
  87
  88                 if (bug_ctx.clear)
  89                         (*bug_ctx.clear) (which_bp);
  90
  91                 printf ("Breakpoint %d removed\n", which_bp);
  92                 return;
  93         }
  94
  95         /* Show a list of breakpoints */
  96
  97         if (strcmp (argv[1], "show") == 0) {
  98                 for (which_bp = 1; which_bp <= MAX_BREAK_POINTS; ++which_bp) {
  99
 100                         switch (which_bp) {
 101                         case 1:
 102                                 addr = GET_IAC1 ();
 103                                 break;
 104                         case 2:
 105                                 addr = GET_IAC2 ();
 106                                 break;
 107                         case 3:
 108                                 addr = GET_IAC3 ();
 109                                 break;
 110                         case 4:
 111                                 addr = GET_IAC4 ();
 112                                 break;
 113                         }
 114
 115                         printf ("Breakpoint [%d]: ", which_bp);
 116                         if (addr == 0)
 117                                 printf ("NOT SET\n");
 118                         else
 119                                 disppc ((unsigned char *) addr, 0, 1, bedbug_puts,
 120                                                 F_RADHEX);
 121                 }
 122                 return;
 123         }
 124
 125         /* Set a breakpoint at the address */
 126
 127         if (!isdigit (argv[1][0])) {
 128                 printf ("Usage:\n%s\n", cmdtp->usage);
 129                 return;
 130         }
 131
 132         addr = simple_strtoul (argv[1], NULL, 16) & 0xfffffffc;
 133
 134         if ((bug_ctx.set) && (which_bp = (*bug_ctx.set) (0, addr)) > 0) {
 135                 printf ("Breakpoint [%d]: ", which_bp);
 136                 disppc ((unsigned char *) addr, 0, 1, bedbug_puts, F_RADHEX);
 137         }
 138
 139         return;
 140 }       /* bedbug405_do_break */
 141 \f
 142
 143
 144 /* ======================================================================
 145  * Handle a breakpoint.  First determine which breakpoint was hit by
 146  * looking at the DeBug Status Register (DBSR), clear the breakpoint
 147  * and enter a mini main loop.  Stay in the loop until the stopped flag
 148  * in the debug context is cleared.
 149  * ====================================================================== */
 150
 151 void bedbug405_break_isr (struct pt_regs *regs)
 152 {
 153         unsigned long dbsr_val;         /* Value of the DBSR    */
 154         unsigned long addr = 0;         /* Address stopped at   */
 155
 156         /* -------------------------------------------------- */
 157
 158         dbsr_val = GET_DBSR ();
 159
 160         if (dbsr_val & DBSR_IA1) {
 161                 bug_ctx.current_bp = 1;
 162                 addr = GET_IAC1 ();
 163                 SET_DBSR (DBSR_IA1);    /* Write a 1 to clear */
 164         } else if (dbsr_val & DBSR_IA2) {
 165                 bug_ctx.current_bp = 2;
 166                 addr = GET_IAC2 ();
 167                 SET_DBSR (DBSR_IA2);    /* Write a 1 to clear */
 168         } else if (dbsr_val & DBSR_IA3) {
 169                 bug_ctx.current_bp = 3;
 170                 addr = GET_IAC3 ();
 171                 SET_DBSR (DBSR_IA3);    /* Write a 1 to clear */
 172         } else if (dbsr_val & DBSR_IA4) {
 173                 bug_ctx.current_bp = 4;
 174                 addr = GET_IAC4 ();
 175                 SET_DBSR (DBSR_IA4);    /* Write a 1 to clear */
 176         }
 177
 178         bedbug_main_loop (addr, regs);
 179         return;
 180 }       /* bedbug405_break_isr */
 181 \f
 182
 183
 184 /* ======================================================================
 185  * Look through all of the hardware breakpoints available to see if one
 186  * is unused.
 187  * ====================================================================== */
 188
 189 int bedbug405_find_empty (void)
 190 {
 191         /* -------------------------------------------------- */
 192
 193         if (GET_IAC1 () == 0)
 194                 return 1;
 195
 196         if (GET_IAC2 () == 0)
 197                 return 2;
 198
 199         if (GET_IAC3 () == 0)
 200                 return 3;
 201
 202         if (GET_IAC4 () == 0)
 203                 return 4;
 204
 205         return 0;
 206 }       /* bedbug405_find_empty */
 207 \f
 208
 209
 210 /* ======================================================================
 211  * Set a breakpoint.  If 'which_bp' is zero then find an unused breakpoint
 212  * number, otherwise reassign the given breakpoint.  If hardware debugging
 213  * is not enabled, then turn it on via the MSR and DBCR0.  Set the break
 214  * address in the appropriate IACx register and enable proper address
 215  * beakpoint in DBCR0.
 216  * ====================================================================== */
 217
 218 int bedbug405_set (int which_bp, unsigned long addr)
 219 {
 220         /* -------------------------------------------------- */
 221
 222         /* Only look if which_bp == 0, else use which_bp */
 223         if ((bug_ctx.find_empty) && (!which_bp) &&
 224                 (which_bp = (*bug_ctx.find_empty) ()) == 0) {
 225                 printf ("All breakpoints in use\n");
 226                 return 0;
 227         }
 228
 229         if (which_bp < 1 || which_bp > MAX_BREAK_POINTS) {
 230                 printf ("Invalid break point # %d\n", which_bp);
 231                 return 0;
 232         }
 233
 234         if (!bug_ctx.hw_debug_enabled) {
 235                 SET_MSR (GET_MSR () | 0x200);   /* set MSR[ DE ] */
 236                 SET_DBCR0 (GET_DBCR0 () | DBCR0_IDM);
 237                 bug_ctx.hw_debug_enabled = 1;
 238         }
 239
 240         switch (which_bp) {
 241         case 1:
 242                 SET_IAC1 (addr);
 243                 SET_DBCR0 (GET_DBCR0 () | DBCR0_IA1);
 244                 break;
 245
 246         case 2:
 247                 SET_IAC2 (addr);
 248                 SET_DBCR0 (GET_DBCR0 () | DBCR0_IA2);
 249                 break;
 250
 251         case 3:
 252                 SET_IAC3 (addr);
 253                 SET_DBCR0 (GET_DBCR0 () | DBCR0_IA3);
 254                 break;
 255
 256         case 4:
 257                 SET_IAC4 (addr);
 258                 SET_DBCR0 (GET_DBCR0 () | DBCR0_IA4);
 259                 break;
 260         }
 261
 262         return which_bp;
 263 }       /* bedbug405_set */
 264 \f
 265
 266
 267 /* ======================================================================
 268  * Disable a specific breakoint by setting the appropriate IACx register
 269  * to zero and claring the instruction address breakpoint in DBCR0.
 270  * ====================================================================== */
 271
 272 int bedbug405_clear (int which_bp)
 273 {
 274         /* -------------------------------------------------- */
 275
 276         if (which_bp < 1 || which_bp > MAX_BREAK_POINTS) {
 277                 printf ("Invalid break point # (%d)\n", which_bp);
 278                 return -1;
 279         }
 280
 281         switch (which_bp) {
 282         case 1:
 283                 SET_IAC1 (0);
 284                 SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA1);
 285                 break;
 286
 287         case 2:
 288                 SET_IAC2 (0);
 289                 SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA2);
 290                 break;
 291
 292         case 3:
 293                 SET_IAC3 (0);
 294                 SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA3);
 295                 break;
 296
 297         case 4:
 298                 SET_IAC4 (0);
 299                 SET_DBCR0 (GET_DBCR0 () & ~DBCR0_IA4);
 300                 break;
 301         }
 302
 303         return 0;
 304 }       /* bedbug405_clear */
 305
 306
 307 /* ====================================================================== */
 308 #endif