| 1 | /**************************************************************************** |
| 2 | |
| 3 | THIS SOFTWARE IS NOT COPYRIGHTED |
| 4 | |
| 5 | HP offers the following for use in the public domain. HP makes no |
| 6 | warranty with regard to the software or it's performance and the |
| 7 | user accepts the software "AS IS" with all faults. |
| 8 | |
| 9 | HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD |
| 10 | TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| 11 | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 12 | |
| 13 | ****************************************************************************/ |
| 14 | |
| 15 | /**************************************************************************** |
| 16 | * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $ |
| 17 | * |
| 18 | * Module name: remcom.c $ |
| 19 | * Revision: 1.34 $ |
| 20 | * Date: 91/03/09 12:29:49 $ |
| 21 | * Contributor: Lake Stevens Instrument Division$ |
| 22 | * |
| 23 | * Description: low level support for gdb debugger. $ |
| 24 | * |
| 25 | * Considerations: only works on target hardware $ |
| 26 | * |
| 27 | * Written by: Glenn Engel $ |
| 28 | * ModuleState: Experimental $ |
| 29 | * |
| 30 | * NOTES: See Below $ |
| 31 | * |
| 32 | * Modified for SPARC by Stu Grossman, Cygnus Support. |
| 33 | * Based on sparc-stub.c, it's modified for SPARClite Debug Unit hardware |
| 34 | * breakpoint support to create sparclite-stub.c, by Kung Hsu, Cygnus Support. |
| 35 | * |
| 36 | * This code has been extensively tested on the Fujitsu SPARClite demo board. |
| 37 | * |
| 38 | * To enable debugger support, two things need to happen. One, a |
| 39 | * call to set_debug_traps() is necessary in order to allow any breakpoints |
| 40 | * or error conditions to be properly intercepted and reported to gdb. |
| 41 | * Two, a breakpoint needs to be generated to begin communication. This |
| 42 | * is most easily accomplished by a call to breakpoint(). Breakpoint() |
| 43 | * simulates a breakpoint by executing a trap #1. |
| 44 | * |
| 45 | ************* |
| 46 | * |
| 47 | * The following gdb commands are supported: |
| 48 | * |
| 49 | * command function Return value |
| 50 | * |
| 51 | * g return the value of the CPU registers hex data or ENN |
| 52 | * G set the value of the CPU registers OK or ENN |
| 53 | * |
| 54 | * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN |
| 55 | * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN |
| 56 | * |
| 57 | * c Resume at current address SNN ( signal NN) |
| 58 | * cAA..AA Continue at address AA..AA SNN |
| 59 | * |
| 60 | * s Step one instruction SNN |
| 61 | * sAA..AA Step one instruction from AA..AA SNN |
| 62 | * |
| 63 | * k kill |
| 64 | * |
| 65 | * ? What was the last sigval ? SNN (signal NN) |
| 66 | * |
| 67 | * bBB..BB Set baud rate to BB..BB OK or BNN, then sets |
| 68 | * baud rate |
| 69 | * |
| 70 | * All commands and responses are sent with a packet which includes a |
| 71 | * checksum. A packet consists of |
| 72 | * |
| 73 | * $<packet info>#<checksum>. |
| 74 | * |
| 75 | * where |
| 76 | * <packet info> :: <characters representing the command or response> |
| 77 | * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> |
| 78 | * |
| 79 | * When a packet is received, it is first acknowledged with either '+' or '-'. |
| 80 | * '+' indicates a successful transfer. '-' indicates a failed transfer. |
| 81 | * |
| 82 | * Example: |
| 83 | * |
| 84 | * Host: Reply: |
| 85 | * $m0,10#2a +$00010203040506070809101112131415#42 |
| 86 | * |
| 87 | ****************************************************************************/ |
| 88 | |
| 89 | #include <string.h> |
| 90 | #include <signal.h> |
| 91 | |
| 92 | /************************************************************************ |
| 93 | * |
| 94 | * external low-level support routines |
| 95 | */ |
| 96 | |
| 97 | extern putDebugChar(); /* write a single character */ |
| 98 | extern getDebugChar(); /* read and return a single char */ |
| 99 | |
| 100 | /************************************************************************/ |
| 101 | /* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ |
| 102 | /* at least NUMREGBYTES*2 are needed for register packets */ |
| 103 | #define BUFMAX 2048 |
| 104 | |
| 105 | static int initialized = 0; /* !0 means we've been initialized */ |
| 106 | |
| 107 | extern void breakinst(); |
| 108 | static void hw_breakpoint(); |
| 109 | static void set_mem_fault_trap(); |
| 110 | static void get_in_break_mode(); |
| 111 | |
| 112 | static const char hexchars[]="0123456789abcdef"; |
| 113 | |
| 114 | #define NUMREGS 80 |
| 115 | |
| 116 | /* Number of bytes of registers. */ |
| 117 | #define NUMREGBYTES (NUMREGS * 4) |
| 118 | enum regnames {G0, G1, G2, G3, G4, G5, G6, G7, |
| 119 | O0, O1, O2, O3, O4, O5, SP, O7, |
| 120 | L0, L1, L2, L3, L4, L5, L6, L7, |
| 121 | I0, I1, I2, I3, I4, I5, FP, I7, |
| 122 | |
| 123 | F0, F1, F2, F3, F4, F5, F6, F7, |
| 124 | F8, F9, F10, F11, F12, F13, F14, F15, |
| 125 | F16, F17, F18, F19, F20, F21, F22, F23, |
| 126 | F24, F25, F26, F27, F28, F29, F30, F31, |
| 127 | Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR, |
| 128 | DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR }; |
| 129 | |
| 130 | /*************************** ASSEMBLY CODE MACROS *************************/ |
| 131 | /* */ |
| 132 | |
| 133 | extern void trap_low(); |
| 134 | |
| 135 | asm(" |
| 136 | .reserve trapstack, 1000 * 4, \"bss\", 8 |
| 137 | |
| 138 | .data |
| 139 | .align 4 |
| 140 | |
| 141 | in_trap_handler: |
| 142 | .word 0 |
| 143 | |
| 144 | .text |
| 145 | .align 4 |
| 146 | |
| 147 | ! This function is called when any SPARC trap (except window overflow or |
| 148 | ! underflow) occurs. It makes sure that the invalid register window is still |
| 149 | ! available before jumping into C code. It will also restore the world if you |
| 150 | ! return from handle_exception. |
| 151 | |
| 152 | .globl _trap_low |
| 153 | _trap_low: |
| 154 | mov %psr, %l0 |
| 155 | mov %wim, %l3 |
| 156 | |
| 157 | srl %l3, %l0, %l4 ! wim >> cwp |
| 158 | cmp %l4, 1 |
| 159 | bne window_fine ! Branch if not in the invalid window |
| 160 | nop |
| 161 | |
| 162 | ! Handle window overflow |
| 163 | |
| 164 | mov %g1, %l4 ! Save g1, we use it to hold the wim |
| 165 | srl %l3, 1, %g1 ! Rotate wim right |
| 166 | tst %g1 |
| 167 | bg good_wim ! Branch if new wim is non-zero |
| 168 | nop |
| 169 | |
| 170 | ! At this point, we need to bring a 1 into the high order bit of the wim. |
| 171 | ! Since we don't want to make any assumptions about the number of register |
| 172 | ! windows, we figure it out dynamically so as to setup the wim correctly. |
| 173 | |
| 174 | not %g1 ! Fill g1 with ones |
| 175 | mov %g1, %wim ! Fill the wim with ones |
| 176 | nop |
| 177 | nop |
| 178 | nop |
| 179 | mov %wim, %g1 ! Read back the wim |
| 180 | inc %g1 ! Now g1 has 1 just to left of wim |
| 181 | srl %g1, 1, %g1 ! Now put 1 at top of wim |
| 182 | mov %g0, %wim ! Clear wim so that subsequent save |
| 183 | nop ! won't trap |
| 184 | nop |
| 185 | nop |
| 186 | |
| 187 | good_wim: |
| 188 | save %g0, %g0, %g0 ! Slip into next window |
| 189 | mov %g1, %wim ! Install the new wim |
| 190 | |
| 191 | std %l0, [%sp + 0 * 4] ! save L & I registers |
| 192 | std %l2, [%sp + 2 * 4] |
| 193 | std %l4, [%sp + 4 * 4] |
| 194 | std %l6, [%sp + 6 * 4] |
| 195 | |
| 196 | std %i0, [%sp + 8 * 4] |
| 197 | std %i2, [%sp + 10 * 4] |
| 198 | std %i4, [%sp + 12 * 4] |
| 199 | std %i6, [%sp + 14 * 4] |
| 200 | |
| 201 | restore ! Go back to trap window. |
| 202 | mov %l4, %g1 ! Restore %g1 |
| 203 | |
| 204 | window_fine: |
| 205 | sethi %hi(in_trap_handler), %l4 |
| 206 | ld [%lo(in_trap_handler) + %l4], %l5 |
| 207 | tst %l5 |
| 208 | bg recursive_trap |
| 209 | inc %l5 |
| 210 | |
| 211 | set trapstack+1000*4, %sp ! Switch to trap stack |
| 212 | |
| 213 | recursive_trap: |
| 214 | st %l5, [%lo(in_trap_handler) + %l4] |
| 215 | sub %sp,(16+1+6+1+80)*4,%sp ! Make room for input & locals |
| 216 | ! + hidden arg + arg spill |
| 217 | ! + doubleword alignment |
| 218 | ! + registers[72] local var |
| 219 | |
| 220 | std %g0, [%sp + (24 + 0) * 4] ! registers[Gx] |
| 221 | std %g2, [%sp + (24 + 2) * 4] |
| 222 | std %g4, [%sp + (24 + 4) * 4] |
| 223 | std %g6, [%sp + (24 + 6) * 4] |
| 224 | |
| 225 | std %i0, [%sp + (24 + 8) * 4] ! registers[Ox] |
| 226 | std %i2, [%sp + (24 + 10) * 4] |
| 227 | std %i4, [%sp + (24 + 12) * 4] |
| 228 | std %i6, [%sp + (24 + 14) * 4] |
| 229 | ! F0->F31 not implemented |
| 230 | mov %y, %l4 |
| 231 | mov %tbr, %l5 |
| 232 | st %l4, [%sp + (24 + 64) * 4] ! Y |
| 233 | st %l0, [%sp + (24 + 65) * 4] ! PSR |
| 234 | st %l3, [%sp + (24 + 66) * 4] ! WIM |
| 235 | st %l5, [%sp + (24 + 67) * 4] ! TBR |
| 236 | st %l1, [%sp + (24 + 68) * 4] ! PC |
| 237 | st %l2, [%sp + (24 + 69) * 4] ! NPC |
| 238 | ! CPSR and FPSR not impl |
| 239 | or %l0, 0xf20, %l4 |
| 240 | mov %l4, %psr ! Turn on traps, disable interrupts |
| 241 | nop |
| 242 | nop |
| 243 | nop |
| 244 | call _get_in_break_mode |
| 245 | nop |
| 246 | nop |
| 247 | nop |
| 248 | |
| 249 | sethi %hi(0xff00), %l5 |
| 250 | or %l5, %lo(0xff00), %l5 |
| 251 | |
| 252 | lda [%l5]0x1, %l4 |
| 253 | st %l4, [%sp + (24 + 72) * 4] ! DIA1, debug instr addr 1 |
| 254 | add %l5, 4, %l5 |
| 255 | lda [%l5]0x1, %l4 |
| 256 | st %l4, [%sp + (24 + 73) * 4] ! DIA2, debug instr addr 2 |
| 257 | add %l5, 4, %l5 |
| 258 | lda [%l5]0x1, %l4 |
| 259 | st %l4, [%sp + (24 + 74) * 4] ! DDA1, debug data addr 1 |
| 260 | add %l5, 4, %l5 |
| 261 | lda [%l5]0x1, %l4 |
| 262 | st %l4, [%sp + (24 + 75) * 4] ! DDA2, debug data addr 2 |
| 263 | add %l5, 4, %l5 |
| 264 | lda [%l5]0x1, %l4 |
| 265 | st %l4, [%sp + (24 + 76) * 4] ! DDV1, debug data val 1 |
| 266 | add %l5, 4, %l5 |
| 267 | lda [%l5]0x1, %l4 |
| 268 | st %l4, [%sp + (24 + 77) * 4] ! DDV2, debug data val 2 |
| 269 | add %l5, 4, %l5 |
| 270 | lda [%l5]0x1, %l4 |
| 271 | st %l4, [%sp + (24 + 78) * 4] ! DCR, debug control reg |
| 272 | add %l5, 4, %l5 |
| 273 | lda [%l5]0x1, %l4 |
| 274 | st %l4, [%sp + (24 + 79) * 4] ! DSR, debug status reg |
| 275 | nop |
| 276 | nop |
| 277 | or %l0, 0xf20, %l4 |
| 278 | mov %l4, %psr ! Turn on traps, disable interrupts |
| 279 | nop |
| 280 | nop |
| 281 | nop |
| 282 | call _handle_exception |
| 283 | add %sp, 24 * 4, %o0 ! Pass address of registers |
| 284 | |
| 285 | ! Reload all of the registers that aren't on the stack |
| 286 | |
| 287 | ld [%sp + (24 + 1) * 4], %g1 ! registers[Gx] |
| 288 | ldd [%sp + (24 + 2) * 4], %g2 |
| 289 | ldd [%sp + (24 + 4) * 4], %g4 |
| 290 | ldd [%sp + (24 + 6) * 4], %g6 |
| 291 | |
| 292 | ldd [%sp + (24 + 8) * 4], %i0 ! registers[Ox] |
| 293 | ldd [%sp + (24 + 10) * 4], %i2 |
| 294 | ldd [%sp + (24 + 12) * 4], %i4 |
| 295 | ldd [%sp + (24 + 14) * 4], %i6 |
| 296 | |
| 297 | sethi %hi(0xff00), %l2 |
| 298 | or %l2, %lo(0xff00), %l2 |
| 299 | ldd [%sp + (24 + 72) * 4], %l4 ! DIA1, debug instr addr 1 |
| 300 | stda %l4, [%l2]0x1 |
| 301 | nop |
| 302 | nop |
| 303 | nop |
| 304 | nop |
| 305 | ldd [%sp + (24 + 74) * 4], %l4 ! DDA1, debug data addr 1 |
| 306 | add %l2, 8, %l2 |
| 307 | stda %l4, [%l2]0x1 |
| 308 | nop |
| 309 | nop |
| 310 | nop |
| 311 | nop |
| 312 | ldd [%sp + (24 + 76) * 4], %l4 ! DDV1, debug data value 1 |
| 313 | add %l2, 8, %l2 |
| 314 | stda %l4, [%l2]0x1 |
| 315 | nop |
| 316 | nop |
| 317 | nop |
| 318 | nop |
| 319 | ld [%sp + (24 + 78) * 4], %l4 ! DCR, debug control reg |
| 320 | ld [%sp + (24 + 79) * 4], %l5 ! DSR, debug control reg |
| 321 | add %l2, 8, %l2 |
| 322 | or %l4, 0x200, %l4 |
| 323 | sta %l4, [%l2]0x1 |
| 324 | add %l2, 4, %l2 |
| 325 | sta %l5, [%l2]0x1 |
| 326 | nop |
| 327 | nop |
| 328 | nop |
| 329 | nop |
| 330 | |
| 331 | ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR |
| 332 | ldd [%sp + (24 + 68) * 4], %l2 ! PC & NPC |
| 333 | |
| 334 | restore ! Ensure that previous window is valid |
| 335 | save %g0, %g0, %g0 ! by causing a window_underflow trap |
| 336 | |
| 337 | mov %l0, %y |
| 338 | mov %l1, %psr ! Make sure that traps are disabled |
| 339 | ! for rett |
| 340 | sethi %hi(in_trap_handler), %l4 |
| 341 | ld [%lo(in_trap_handler) + %l4], %l5 |
| 342 | dec %l5 |
| 343 | st %l5, [%lo(in_trap_handler) + %l4] |
| 344 | |
| 345 | jmpl %l2, %g0 ! Restore old PC |
| 346 | rett %l3 ! Restore old nPC |
| 347 | "); |
| 348 | |
| 349 | /* Convert ch from a hex digit to an int */ |
| 350 | |
| 351 | static int |
| 352 | hex(ch) |
| 353 | unsigned char ch; |
| 354 | { |
| 355 | if (ch >= 'a' && ch <= 'f') |
| 356 | return ch-'a'+10; |
| 357 | if (ch >= '0' && ch <= '9') |
| 358 | return ch-'0'; |
| 359 | if (ch >= 'A' && ch <= 'F') |
| 360 | return ch-'A'+10; |
| 361 | return -1; |
| 362 | } |
| 363 | |
| 364 | /* scan for the sequence $<data>#<checksum> */ |
| 365 | |
| 366 | static void |
| 367 | getpacket(buffer) |
| 368 | char *buffer; |
| 369 | { |
| 370 | unsigned char checksum; |
| 371 | unsigned char xmitcsum; |
| 372 | int i; |
| 373 | int count; |
| 374 | unsigned char ch; |
| 375 | |
| 376 | do |
| 377 | { |
| 378 | /* wait around for the start character, ignore all other characters */ |
| 379 | while ((ch = (getDebugChar() & 0x7f)) != '$') ; |
| 380 | |
| 381 | checksum = 0; |
| 382 | xmitcsum = -1; |
| 383 | |
| 384 | count = 0; |
| 385 | |
| 386 | /* now, read until a # or end of buffer is found */ |
| 387 | while (count < BUFMAX) |
| 388 | { |
| 389 | ch = getDebugChar() & 0x7f; |
| 390 | if (ch == '#') |
| 391 | break; |
| 392 | checksum = checksum + ch; |
| 393 | buffer[count] = ch; |
| 394 | count = count + 1; |
| 395 | } |
| 396 | |
| 397 | if (count >= BUFMAX) |
| 398 | continue; |
| 399 | |
| 400 | buffer[count] = 0; |
| 401 | |
| 402 | if (ch == '#') |
| 403 | { |
| 404 | xmitcsum = hex(getDebugChar() & 0x7f) << 4; |
| 405 | xmitcsum |= hex(getDebugChar() & 0x7f); |
| 406 | #if 0 |
| 407 | /* Humans shouldn't have to figure out checksums to type to it. */ |
| 408 | putDebugChar ('+'); |
| 409 | return; |
| 410 | #endif |
| 411 | if (checksum != xmitcsum) |
| 412 | putDebugChar('-'); /* failed checksum */ |
| 413 | else |
| 414 | { |
| 415 | putDebugChar('+'); /* successful transfer */ |
| 416 | /* if a sequence char is present, reply the sequence ID */ |
| 417 | if (buffer[2] == ':') |
| 418 | { |
| 419 | putDebugChar(buffer[0]); |
| 420 | putDebugChar(buffer[1]); |
| 421 | /* remove sequence chars from buffer */ |
| 422 | count = strlen(buffer); |
| 423 | for (i=3; i <= count; i++) |
| 424 | buffer[i-3] = buffer[i]; |
| 425 | } |
| 426 | } |
| 427 | } |
| 428 | } |
| 429 | while (checksum != xmitcsum); |
| 430 | } |
| 431 | |
| 432 | /* send the packet in buffer. */ |
| 433 | |
| 434 | static void |
| 435 | putpacket(buffer) |
| 436 | unsigned char *buffer; |
| 437 | { |
| 438 | unsigned char checksum; |
| 439 | int count; |
| 440 | unsigned char ch; |
| 441 | |
| 442 | /* $<packet info>#<checksum>. */ |
| 443 | do |
| 444 | { |
| 445 | putDebugChar('$'); |
| 446 | checksum = 0; |
| 447 | count = 0; |
| 448 | |
| 449 | while (ch = buffer[count]) |
| 450 | { |
| 451 | if (! putDebugChar(ch)) |
| 452 | return; |
| 453 | checksum += ch; |
| 454 | count += 1; |
| 455 | } |
| 456 | |
| 457 | putDebugChar('#'); |
| 458 | putDebugChar(hexchars[checksum >> 4]); |
| 459 | putDebugChar(hexchars[checksum & 0xf]); |
| 460 | |
| 461 | } |
| 462 | while ((getDebugChar() & 0x7f) != '+'); |
| 463 | } |
| 464 | |
| 465 | static char remcomInBuffer[BUFMAX]; |
| 466 | static char remcomOutBuffer[BUFMAX]; |
| 467 | |
| 468 | /* Indicate to caller of mem2hex or hex2mem that there has been an |
| 469 | error. */ |
| 470 | static volatile int mem_err = 0; |
| 471 | |
| 472 | /* Convert the memory pointed to by mem into hex, placing result in buf. |
| 473 | * Return a pointer to the last char put in buf (null), in case of mem fault, |
| 474 | * return 0. |
| 475 | * If MAY_FAULT is non-zero, then we will handle memory faults by returning |
| 476 | * a 0, else treat a fault like any other fault in the stub. |
| 477 | */ |
| 478 | |
| 479 | static unsigned char * |
| 480 | mem2hex(mem, buf, count, may_fault) |
| 481 | unsigned char *mem; |
| 482 | unsigned char *buf; |
| 483 | int count; |
| 484 | int may_fault; |
| 485 | { |
| 486 | unsigned char ch; |
| 487 | |
| 488 | set_mem_fault_trap(may_fault); |
| 489 | |
| 490 | while (count-- > 0) |
| 491 | { |
| 492 | ch = *mem++; |
| 493 | if (mem_err) |
| 494 | return 0; |
| 495 | *buf++ = hexchars[ch >> 4]; |
| 496 | *buf++ = hexchars[ch & 0xf]; |
| 497 | } |
| 498 | |
| 499 | *buf = 0; |
| 500 | |
| 501 | set_mem_fault_trap(0); |
| 502 | |
| 503 | return buf; |
| 504 | } |
| 505 | |
| 506 | /* convert the hex array pointed to by buf into binary to be placed in mem |
| 507 | * return a pointer to the character AFTER the last byte written */ |
| 508 | |
| 509 | static char * |
| 510 | hex2mem(buf, mem, count, may_fault) |
| 511 | unsigned char *buf; |
| 512 | unsigned char *mem; |
| 513 | int count; |
| 514 | int may_fault; |
| 515 | { |
| 516 | int i; |
| 517 | unsigned char ch; |
| 518 | |
| 519 | set_mem_fault_trap(may_fault); |
| 520 | |
| 521 | for (i=0; i<count; i++) |
| 522 | { |
| 523 | ch = hex(*buf++) << 4; |
| 524 | ch |= hex(*buf++); |
| 525 | *mem++ = ch; |
| 526 | if (mem_err) |
| 527 | return 0; |
| 528 | } |
| 529 | |
| 530 | set_mem_fault_trap(0); |
| 531 | |
| 532 | return mem; |
| 533 | } |
| 534 | |
| 535 | /* This table contains the mapping between SPARC hardware trap types, and |
| 536 | signals, which are primarily what GDB understands. It also indicates |
| 537 | which hardware traps we need to commandeer when initializing the stub. */ |
| 538 | |
| 539 | static struct hard_trap_info |
| 540 | { |
| 541 | unsigned char tt; /* Trap type code for SPARClite */ |
| 542 | unsigned char signo; /* Signal that we map this trap into */ |
| 543 | } hard_trap_info[] = { |
| 544 | {1, SIGSEGV}, /* instruction access error */ |
| 545 | {2, SIGILL}, /* privileged instruction */ |
| 546 | {3, SIGILL}, /* illegal instruction */ |
| 547 | {4, SIGEMT}, /* fp disabled */ |
| 548 | {36, SIGEMT}, /* cp disabled */ |
| 549 | {7, SIGBUS}, /* mem address not aligned */ |
| 550 | {9, SIGSEGV}, /* data access exception */ |
| 551 | {10, SIGEMT}, /* tag overflow */ |
| 552 | {128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */ |
| 553 | {255, SIGTRAP}, /* hardware breakpoint */ |
| 554 | {0, 0} /* Must be last */ |
| 555 | }; |
| 556 | |
| 557 | /* Set up exception handlers for tracing and breakpoints */ |
| 558 | |
| 559 | void |
| 560 | set_debug_traps() |
| 561 | { |
| 562 | struct hard_trap_info *ht; |
| 563 | |
| 564 | for (ht = hard_trap_info; ht->tt && ht->signo; ht++) |
| 565 | exceptionHandler(ht->tt, trap_low); |
| 566 | |
| 567 | /* In case GDB is started before us, ack any packets (presumably |
| 568 | "$?#xx") sitting there. */ |
| 569 | |
| 570 | putDebugChar ('+'); |
| 571 | |
| 572 | initialized = 1; |
| 573 | } |
| 574 | |
| 575 | asm (" |
| 576 | ! Trap handler for memory errors. This just sets mem_err to be non-zero. It |
| 577 | ! assumes that %l1 is non-zero. This should be safe, as it is doubtful that |
| 578 | ! 0 would ever contain code that could mem fault. This routine will skip |
| 579 | ! past the faulting instruction after setting mem_err. |
| 580 | |
| 581 | .text |
| 582 | .align 4 |
| 583 | |
| 584 | _fltr_set_mem_err: |
| 585 | sethi %hi(_mem_err), %l0 |
| 586 | st %l1, [%l0 + %lo(_mem_err)] |
| 587 | jmpl %l2, %g0 |
| 588 | rett %l2+4 |
| 589 | "); |
| 590 | |
| 591 | static void |
| 592 | set_mem_fault_trap(enable) |
| 593 | int enable; |
| 594 | { |
| 595 | extern void fltr_set_mem_err(); |
| 596 | mem_err = 0; |
| 597 | |
| 598 | if (enable) |
| 599 | exceptionHandler(9, fltr_set_mem_err); |
| 600 | else |
| 601 | exceptionHandler(9, trap_low); |
| 602 | } |
| 603 | |
| 604 | asm (" |
| 605 | .text |
| 606 | .align 4 |
| 607 | |
| 608 | _dummy_hw_breakpoint: |
| 609 | jmpl %l2, %g0 |
| 610 | rett %l2+4 |
| 611 | nop |
| 612 | nop |
| 613 | "); |
| 614 | |
| 615 | static void |
| 616 | set_hw_breakpoint_trap(enable) |
| 617 | int enable; |
| 618 | { |
| 619 | extern void dummy_hw_breakpoint(); |
| 620 | |
| 621 | if (enable) |
| 622 | exceptionHandler(255, dummy_hw_breakpoint); |
| 623 | else |
| 624 | exceptionHandler(255, trap_low); |
| 625 | } |
| 626 | |
| 627 | static void |
| 628 | get_in_break_mode() |
| 629 | { |
| 630 | set_hw_breakpoint_trap(1); |
| 631 | |
| 632 | asm(" |
| 633 | sethi %hi(0xff10), %l4 |
| 634 | or %l4, %lo(0xff10), %l4 |
| 635 | sta %g0, [%l4]0x1 |
| 636 | nop |
| 637 | nop |
| 638 | nop |
| 639 | "); |
| 640 | |
| 641 | set_hw_breakpoint_trap(0); |
| 642 | } |
| 643 | |
| 644 | /* Convert the SPARC hardware trap type code to a unix signal number. */ |
| 645 | |
| 646 | static int |
| 647 | computeSignal(tt) |
| 648 | int tt; |
| 649 | { |
| 650 | struct hard_trap_info *ht; |
| 651 | |
| 652 | for (ht = hard_trap_info; ht->tt && ht->signo; ht++) |
| 653 | if (ht->tt == tt) |
| 654 | return ht->signo; |
| 655 | |
| 656 | return SIGHUP; /* default for things we don't know about */ |
| 657 | } |
| 658 | |
| 659 | /* |
| 660 | * While we find nice hex chars, build an int. |
| 661 | * Return number of chars processed. |
| 662 | */ |
| 663 | |
| 664 | static int |
| 665 | hexToInt(char **ptr, int *intValue) |
| 666 | { |
| 667 | int numChars = 0; |
| 668 | int hexValue; |
| 669 | |
| 670 | *intValue = 0; |
| 671 | |
| 672 | while (**ptr) |
| 673 | { |
| 674 | hexValue = hex(**ptr); |
| 675 | if (hexValue < 0) |
| 676 | break; |
| 677 | |
| 678 | *intValue = (*intValue << 4) | hexValue; |
| 679 | numChars ++; |
| 680 | |
| 681 | (*ptr)++; |
| 682 | } |
| 683 | |
| 684 | return (numChars); |
| 685 | } |
| 686 | |
| 687 | /* |
| 688 | * This function does all command procesing for interfacing to gdb. It |
| 689 | * returns 1 if you should skip the instruction at the trap address, 0 |
| 690 | * otherwise. |
| 691 | */ |
| 692 | |
| 693 | |
| 694 | static void |
| 695 | handle_exception (registers) |
| 696 | unsigned long *registers; |
| 697 | { |
| 698 | int tt; /* Trap type */ |
| 699 | int sigval; |
| 700 | int addr; |
| 701 | int length; |
| 702 | char *ptr; |
| 703 | unsigned long *sp; |
| 704 | unsigned long dsr; |
| 705 | |
| 706 | /* First, we must force all of the windows to be spilled out */ |
| 707 | |
| 708 | asm(" save %sp, -64, %sp |
| 709 | save %sp, -64, %sp |
| 710 | save %sp, -64, %sp |
| 711 | save %sp, -64, %sp |
| 712 | save %sp, -64, %sp |
| 713 | save %sp, -64, %sp |
| 714 | save %sp, -64, %sp |
| 715 | save %sp, -64, %sp |
| 716 | restore |
| 717 | restore |
| 718 | restore |
| 719 | restore |
| 720 | restore |
| 721 | restore |
| 722 | restore |
| 723 | restore |
| 724 | "); |
| 725 | |
| 726 | if (registers[PC] == (unsigned long)breakinst) |
| 727 | { |
| 728 | registers[PC] = registers[NPC]; |
| 729 | registers[NPC] += 4; |
| 730 | } |
| 731 | sp = (unsigned long *)registers[SP]; |
| 732 | |
| 733 | dsr = (unsigned long)registers[DSR]; |
| 734 | if (dsr & 0x3c) |
| 735 | { |
| 736 | tt = 255; |
| 737 | } |
| 738 | else |
| 739 | { |
| 740 | tt = (registers[TBR] >> 4) & 0xff; |
| 741 | } |
| 742 | |
| 743 | /* reply to host that an exception has occurred */ |
| 744 | sigval = computeSignal(tt); |
| 745 | ptr = remcomOutBuffer; |
| 746 | |
| 747 | *ptr++ = 'T'; |
| 748 | *ptr++ = hexchars[sigval >> 4]; |
| 749 | *ptr++ = hexchars[sigval & 0xf]; |
| 750 | |
| 751 | *ptr++ = hexchars[PC >> 4]; |
| 752 | *ptr++ = hexchars[PC & 0xf]; |
| 753 | *ptr++ = ':'; |
| 754 | ptr = mem2hex((char *)®isters[PC], ptr, 4, 0); |
| 755 | *ptr++ = ';'; |
| 756 | |
| 757 | *ptr++ = hexchars[FP >> 4]; |
| 758 | *ptr++ = hexchars[FP & 0xf]; |
| 759 | *ptr++ = ':'; |
| 760 | ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */ |
| 761 | *ptr++ = ';'; |
| 762 | |
| 763 | *ptr++ = hexchars[SP >> 4]; |
| 764 | *ptr++ = hexchars[SP & 0xf]; |
| 765 | *ptr++ = ':'; |
| 766 | ptr = mem2hex((char *)&sp, ptr, 4, 0); |
| 767 | *ptr++ = ';'; |
| 768 | |
| 769 | *ptr++ = hexchars[NPC >> 4]; |
| 770 | *ptr++ = hexchars[NPC & 0xf]; |
| 771 | *ptr++ = ':'; |
| 772 | ptr = mem2hex((char *)®isters[NPC], ptr, 4, 0); |
| 773 | *ptr++ = ';'; |
| 774 | |
| 775 | *ptr++ = hexchars[O7 >> 4]; |
| 776 | *ptr++ = hexchars[O7 & 0xf]; |
| 777 | *ptr++ = ':'; |
| 778 | ptr = mem2hex((char *)®isters[O7], ptr, 4, 0); |
| 779 | *ptr++ = ';'; |
| 780 | |
| 781 | *ptr++ = 0; |
| 782 | |
| 783 | putpacket(remcomOutBuffer); |
| 784 | |
| 785 | while (1) |
| 786 | { |
| 787 | remcomOutBuffer[0] = 0; |
| 788 | |
| 789 | getpacket(remcomInBuffer); |
| 790 | switch (remcomInBuffer[0]) |
| 791 | { |
| 792 | case '?': |
| 793 | remcomOutBuffer[0] = 'S'; |
| 794 | remcomOutBuffer[1] = hexchars[sigval >> 4]; |
| 795 | remcomOutBuffer[2] = hexchars[sigval & 0xf]; |
| 796 | remcomOutBuffer[3] = 0; |
| 797 | break; |
| 798 | |
| 799 | case 'd': |
| 800 | /* toggle debug flag */ |
| 801 | break; |
| 802 | |
| 803 | case 'g': /* return the value of the CPU registers */ |
| 804 | { |
| 805 | ptr = remcomOutBuffer; |
| 806 | ptr = mem2hex((char *)registers, ptr, 16 * 4, 0); /* G & O regs */ |
| 807 | ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */ |
| 808 | memset(ptr, '0', 32 * 8); /* Floating point */ |
| 809 | ptr = mem2hex((char *)®isters[Y], |
| 810 | ptr + 32 * 4 * 2, |
| 811 | 8 * 4, |
| 812 | 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */ |
| 813 | mem2hex((char *)®isters[DIA1], ptr, |
| 814 | 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */ |
| 815 | } |
| 816 | break; |
| 817 | |
| 818 | case 'G': /* set the value of the CPU registers - return OK */ |
| 819 | { |
| 820 | unsigned long *newsp, psr; |
| 821 | |
| 822 | psr = registers[PSR]; |
| 823 | |
| 824 | ptr = &remcomInBuffer[1]; |
| 825 | hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */ |
| 826 | hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */ |
| 827 | hex2mem(ptr + 64 * 4 * 2, (char *)®isters[Y], |
| 828 | 8 * 4, 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */ |
| 829 | hex2mem(ptr + 72 * 4 * 2, (char *)®isters[DIA1], |
| 830 | 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */ |
| 831 | |
| 832 | /* See if the stack pointer has moved. If so, then copy the saved |
| 833 | locals and ins to the new location. This keeps the window |
| 834 | overflow and underflow routines happy. */ |
| 835 | |
| 836 | newsp = (unsigned long *)registers[SP]; |
| 837 | if (sp != newsp) |
| 838 | sp = memcpy(newsp, sp, 16 * 4); |
| 839 | |
| 840 | /* Don't allow CWP to be modified. */ |
| 841 | |
| 842 | if (psr != registers[PSR]) |
| 843 | registers[PSR] = (psr & 0x1f) | (registers[PSR] & ~0x1f); |
| 844 | |
| 845 | strcpy(remcomOutBuffer,"OK"); |
| 846 | } |
| 847 | break; |
| 848 | |
| 849 | case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ |
| 850 | /* Try to read %x,%x. */ |
| 851 | |
| 852 | ptr = &remcomInBuffer[1]; |
| 853 | |
| 854 | if (hexToInt(&ptr, &addr) |
| 855 | && *ptr++ == ',' |
| 856 | && hexToInt(&ptr, &length)) |
| 857 | { |
| 858 | if (mem2hex((char *)addr, remcomOutBuffer, length, 1)) |
| 859 | break; |
| 860 | |
| 861 | strcpy (remcomOutBuffer, "E03"); |
| 862 | } |
| 863 | else |
| 864 | strcpy(remcomOutBuffer,"E01"); |
| 865 | break; |
| 866 | |
| 867 | case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ |
| 868 | /* Try to read '%x,%x:'. */ |
| 869 | |
| 870 | ptr = &remcomInBuffer[1]; |
| 871 | |
| 872 | if (hexToInt(&ptr, &addr) |
| 873 | && *ptr++ == ',' |
| 874 | && hexToInt(&ptr, &length) |
| 875 | && *ptr++ == ':') |
| 876 | { |
| 877 | if (hex2mem(ptr, (char *)addr, length, 1)) |
| 878 | strcpy(remcomOutBuffer, "OK"); |
| 879 | else |
| 880 | strcpy(remcomOutBuffer, "E03"); |
| 881 | } |
| 882 | else |
| 883 | strcpy(remcomOutBuffer, "E02"); |
| 884 | break; |
| 885 | |
| 886 | case 'c': /* cAA..AA Continue at address AA..AA(optional) */ |
| 887 | /* try to read optional parameter, pc unchanged if no parm */ |
| 888 | |
| 889 | ptr = &remcomInBuffer[1]; |
| 890 | if (hexToInt(&ptr, &addr)) |
| 891 | { |
| 892 | registers[PC] = addr; |
| 893 | registers[NPC] = addr + 4; |
| 894 | } |
| 895 | |
| 896 | /* Need to flush the instruction cache here, as we may have deposited a |
| 897 | breakpoint, and the icache probably has no way of knowing that a data ref to |
| 898 | some location may have changed something that is in the instruction cache. |
| 899 | */ |
| 900 | |
| 901 | flush_i_cache(); |
| 902 | return; |
| 903 | |
| 904 | /* kill the program */ |
| 905 | case 'k' : /* do nothing */ |
| 906 | break; |
| 907 | #if 0 |
| 908 | case 't': /* Test feature */ |
| 909 | asm (" std %f30,[%sp]"); |
| 910 | break; |
| 911 | #endif |
| 912 | case 'r': /* Reset */ |
| 913 | asm ("call 0 |
| 914 | nop "); |
| 915 | break; |
| 916 | |
| 917 | #if 0 |
| 918 | Disabled until we can unscrew this properly |
| 919 | |
| 920 | case 'b': /* bBB... Set baud rate to BB... */ |
| 921 | { |
| 922 | int baudrate; |
| 923 | extern void set_timer_3(); |
| 924 | |
| 925 | ptr = &remcomInBuffer[1]; |
| 926 | if (!hexToInt(&ptr, &baudrate)) |
| 927 | { |
| 928 | strcpy(remcomOutBuffer,"B01"); |
| 929 | break; |
| 930 | } |
| 931 | |
| 932 | /* Convert baud rate to uart clock divider */ |
| 933 | switch (baudrate) |
| 934 | { |
| 935 | case 38400: |
| 936 | baudrate = 16; |
| 937 | break; |
| 938 | case 19200: |
| 939 | baudrate = 33; |
| 940 | break; |
| 941 | case 9600: |
| 942 | baudrate = 65; |
| 943 | break; |
| 944 | default: |
| 945 | strcpy(remcomOutBuffer,"B02"); |
| 946 | goto x1; |
| 947 | } |
| 948 | |
| 949 | putpacket("OK"); /* Ack before changing speed */ |
| 950 | set_timer_3(baudrate); /* Set it */ |
| 951 | } |
| 952 | x1: break; |
| 953 | #endif |
| 954 | } /* switch */ |
| 955 | |
| 956 | /* reply to the request */ |
| 957 | putpacket(remcomOutBuffer); |
| 958 | } |
| 959 | } |
| 960 | |
| 961 | /* This function will generate a breakpoint exception. It is used at the |
| 962 | beginning of a program to sync up with a debugger and can be used |
| 963 | otherwise as a quick means to stop program execution and "break" into |
| 964 | the debugger. */ |
| 965 | |
| 966 | void |
| 967 | breakpoint() |
| 968 | { |
| 969 | if (!initialized) |
| 970 | return; |
| 971 | |
| 972 | asm(" .globl _breakinst |
| 973 | |
| 974 | _breakinst: ta 1 |
| 975 | "); |
| 976 | } |
| 977 | |
| 978 | static void |
| 979 | hw_breakpoint() |
| 980 | { |
| 981 | asm(" |
| 982 | ta 127 |
| 983 | "); |
| 984 | } |