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Diffstat (limited to 'gdb/sparc-stub.c')
| -rw-r--r-- | gdb/sparc-stub.c | 846 |
1 files changed, 0 insertions, 846 deletions
diff --git a/gdb/sparc-stub.c b/gdb/sparc-stub.c deleted file mode 100644 index 7da65c2..0000000 --- a/gdb/sparc-stub.c +++ /dev/null @@ -1,846 +0,0 @@ -/**************************************************************************** - - THIS SOFTWARE IS NOT COPYRIGHTED - - HP offers the following for use in the public domain. HP makes no - warranty with regard to the software or it's performance and the - user accepts the software "AS IS" with all faults. - - HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD - TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES - OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. - -****************************************************************************/ - -/**************************************************************************** - * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $ - * - * Module name: remcom.c $ - * Revision: 1.34 $ - * Date: 91/03/09 12:29:49 $ - * Contributor: Lake Stevens Instrument Division$ - * - * Description: low level support for gdb debugger. $ - * - * Considerations: only works on target hardware $ - * - * Written by: Glenn Engel $ - * ModuleState: Experimental $ - * - * NOTES: See Below $ - * - * Modified for SPARC by Stu Grossman, Cygnus Support. - * - * This code has been extensively tested on the Fujitsu SPARClite demo board. - * - * To enable debugger support, two things need to happen. One, a - * call to set_debug_traps() is necessary in order to allow any breakpoints - * or error conditions to be properly intercepted and reported to gdb. - * Two, a breakpoint needs to be generated to begin communication. This - * is most easily accomplished by a call to breakpoint(). Breakpoint() - * simulates a breakpoint by executing a trap #1. - * - ************* - * - * The following gdb commands are supported: - * - * command function Return value - * - * g return the value of the CPU registers hex data or ENN - * G set the value of the CPU registers OK or ENN - * - * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN - * MAA..AA,LLLL: Write LLLL bytes at address AA.AA OK or ENN - * - * c Resume at current address SNN ( signal NN) - * cAA..AA Continue at address AA..AA SNN - * - * s Step one instruction SNN - * sAA..AA Step one instruction from AA..AA SNN - * - * k kill - * - * ? What was the last sigval ? SNN (signal NN) - * - * bBB..BB Set baud rate to BB..BB OK or BNN, then sets - * baud rate - * - * All commands and responses are sent with a packet which includes a - * checksum. A packet consists of - * - * $<packet info>#<checksum>. - * - * where - * <packet info> :: <characters representing the command or response> - * <checksum> :: < two hex digits computed as modulo 256 sum of <packetinfo>> - * - * When a packet is received, it is first acknowledged with either '+' or '-'. - * '+' indicates a successful transfer. '-' indicates a failed transfer. - * - * Example: - * - * Host: Reply: - * $m0,10#2a +$00010203040506070809101112131415#42 - * - ****************************************************************************/ - -#include <string.h> -#include <signal.h> - -/************************************************************************ - * - * external low-level support routines - */ - -extern void putDebugChar(); /* write a single character */ -extern int getDebugChar(); /* read and return a single char */ - -/************************************************************************/ -/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/ -/* at least NUMREGBYTES*2 are needed for register packets */ -#define BUFMAX 2048 - -static int initialized = 0; /* !0 means we've been initialized */ - -static void set_mem_fault_trap(); - -static const char hexchars[]="0123456789abcdef"; - -#define NUMREGS 72 - -/* Number of bytes of registers. */ -#define NUMREGBYTES (NUMREGS * 4) -enum regnames {G0, G1, G2, G3, G4, G5, G6, G7, - O0, O1, O2, O3, O4, O5, SP, O7, - L0, L1, L2, L3, L4, L5, L6, L7, - I0, I1, I2, I3, I4, I5, FP, I7, - - F0, F1, F2, F3, F4, F5, F6, F7, - F8, F9, F10, F11, F12, F13, F14, F15, - F16, F17, F18, F19, F20, F21, F22, F23, - F24, F25, F26, F27, F28, F29, F30, F31, - Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR }; - -/*************************** ASSEMBLY CODE MACROS *************************/ -/* */ - -extern void trap_low(); - -asm(" - .reserve trapstack, 1000 * 4, \"bss\", 8 - - .data - .align 4 - -in_trap_handler: - .word 0 - - .text - .align 4 - -! This function is called when any SPARC trap (except window overflow or -! underflow) occurs. It makes sure that the invalid register window is still -! available before jumping into C code. It will also restore the world if you -! return from handle_exception. - - .globl _trap_low -_trap_low: - mov %psr, %l0 - mov %wim, %l3 - - srl %l3, %l0, %l4 ! wim >> cwp - cmp %l4, 1 - bne window_fine ! Branch if not in the invalid window - nop - -! Handle window overflow - - mov %g1, %l4 ! Save g1, we use it to hold the wim - srl %l3, 1, %g1 ! Rotate wim right - tst %g1 - bg good_wim ! Branch if new wim is non-zero - nop - -! At this point, we need to bring a 1 into the high order bit of the wim. -! Since we don't want to make any assumptions about the number of register -! windows, we figure it out dynamically so as to setup the wim correctly. - - not %g1 ! Fill g1 with ones - mov %g1, %wim ! Fill the wim with ones - nop - nop - nop - mov %wim, %g1 ! Read back the wim - inc %g1 ! Now g1 has 1 just to left of wim - srl %g1, 1, %g1 ! Now put 1 at top of wim - mov %g0, %wim ! Clear wim so that subsequent save - nop ! won't trap - nop - nop - -good_wim: - save %g0, %g0, %g0 ! Slip into next window - mov %g1, %wim ! Install the new wim - - std %l0, [%sp + 0 * 4] ! save L & I registers - std %l2, [%sp + 2 * 4] - std %l4, [%sp + 4 * 4] - std %l6, [%sp + 6 * 4] - - std %i0, [%sp + 8 * 4] - std %i2, [%sp + 10 * 4] - std %i4, [%sp + 12 * 4] - std %i6, [%sp + 14 * 4] - - restore ! Go back to trap window. - mov %l4, %g1 ! Restore %g1 - -window_fine: - sethi %hi(in_trap_handler), %l4 - ld [%lo(in_trap_handler) + %l4], %l5 - tst %l5 - bg recursive_trap - inc %l5 - - set trapstack+1000*4, %sp ! Switch to trap stack - -recursive_trap: - st %l5, [%lo(in_trap_handler) + %l4] - sub %sp,(16+1+6+1+72)*4,%sp ! Make room for input & locals - ! + hidden arg + arg spill - ! + doubleword alignment - ! + registers[72] local var - - std %g0, [%sp + (24 + 0) * 4] ! registers[Gx] - std %g2, [%sp + (24 + 2) * 4] - std %g4, [%sp + (24 + 4) * 4] - std %g6, [%sp + (24 + 6) * 4] - - std %i0, [%sp + (24 + 8) * 4] ! registers[Ox] - std %i2, [%sp + (24 + 10) * 4] - std %i4, [%sp + (24 + 12) * 4] - std %i6, [%sp + (24 + 14) * 4] - ! F0->F31 not implemented - mov %y, %l4 - mov %tbr, %l5 - st %l4, [%sp + (24 + 64) * 4] ! Y - st %l0, [%sp + (24 + 65) * 4] ! PSR - st %l3, [%sp + (24 + 66) * 4] ! WIM - st %l5, [%sp + (24 + 67) * 4] ! TBR - st %l1, [%sp + (24 + 68) * 4] ! PC - st %l2, [%sp + (24 + 69) * 4] ! NPC - - ! CPSR and FPSR not impl - - or %l0, 0xf20, %l4 - mov %l4, %psr ! Turn on traps, disable interrupts - - call _handle_exception - add %sp, 24 * 4, %o0 ! Pass address of registers - -! Reload all of the registers that aren't on the stack - - ld [%sp + (24 + 1) * 4], %g1 ! registers[Gx] - ldd [%sp + (24 + 2) * 4], %g2 - ldd [%sp + (24 + 4) * 4], %g4 - ldd [%sp + (24 + 6) * 4], %g6 - - ldd [%sp + (24 + 8) * 4], %i0 ! registers[Ox] - ldd [%sp + (24 + 10) * 4], %i2 - ldd [%sp + (24 + 12) * 4], %i4 - ldd [%sp + (24 + 14) * 4], %i6 - - ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR - ldd [%sp + (24 + 68) * 4], %l2 ! PC & NPC - - restore ! Ensure that previous window is valid - save %g0, %g0, %g0 ! by causing a window_underflow trap - - mov %l0, %y - mov %l1, %psr ! Make sure that traps are disabled - ! for rett - - sethi %hi(in_trap_handler), %l4 - ld [%lo(in_trap_handler) + %l4], %l5 - dec %l5 - st %l5, [%lo(in_trap_handler) + %l4] - - jmpl %l2, %g0 ! Restore old PC - rett %l3 ! Restore old nPC -"); - -/* Convert ch from a hex digit to an int */ - -static int -hex(ch) - unsigned char ch; -{ - if (ch >= 'a' && ch <= 'f') - return ch-'a'+10; - if (ch >= '0' && ch <= '9') - return ch-'0'; - if (ch >= 'A' && ch <= 'F') - return ch-'A'+10; - return -1; -} - -/* scan for the sequence $<data>#<checksum> */ - -static void -getpacket(buffer) - char *buffer; -{ - unsigned char checksum; - unsigned char xmitcsum; - int i; - int count; - unsigned char ch; - - do - { - /* wait around for the start character, ignore all other characters */ - while ((ch = (getDebugChar() & 0x7f)) != '$') ; - - checksum = 0; - xmitcsum = -1; - - count = 0; - - /* now, read until a # or end of buffer is found */ - while (count < BUFMAX) - { - ch = getDebugChar() & 0x7f; - if (ch == '#') - break; - checksum = checksum + ch; - buffer[count] = ch; - count = count + 1; - } - - if (count >= BUFMAX) - continue; - - buffer[count] = 0; - - if (ch == '#') - { - xmitcsum = hex(getDebugChar() & 0x7f) << 4; - xmitcsum |= hex(getDebugChar() & 0x7f); -#if 0 - /* Humans shouldn't have to figure out checksums to type to it. */ - putDebugChar ('+'); - return; -#endif - if (checksum != xmitcsum) - putDebugChar('-'); /* failed checksum */ - else - { - putDebugChar('+'); /* successful transfer */ - /* if a sequence char is present, reply the sequence ID */ - if (buffer[2] == ':') - { - putDebugChar(buffer[0]); - putDebugChar(buffer[1]); - /* remove sequence chars from buffer */ - count = strlen(buffer); - for (i=3; i <= count; i++) - buffer[i-3] = buffer[i]; - } - } - } - } - while (checksum != xmitcsum); -} - -/* send the packet in buffer. */ - -static void -putpacket(buffer) - unsigned char *buffer; -{ - unsigned char checksum; - int count; - unsigned char ch; - - /* $<packet info>#<checksum>. */ - do - { - putDebugChar('$'); - checksum = 0; - count = 0; - - while (ch = buffer[count]) - { - putDebugChar(ch); - checksum += ch; - count += 1; - } - - putDebugChar('#'); - putDebugChar(hexchars[checksum >> 4]); - putDebugChar(hexchars[checksum & 0xf]); - - } - while ((getDebugChar() & 0x7f) != '+'); -} - -static char remcomInBuffer[BUFMAX]; -static char remcomOutBuffer[BUFMAX]; - -/* Indicate to caller of mem2hex or hex2mem that there has been an - error. */ -static volatile int mem_err = 0; - -/* Convert the memory pointed to by mem into hex, placing result in buf. - * Return a pointer to the last char put in buf (null), in case of mem fault, - * return 0. - * If MAY_FAULT is non-zero, then we will handle memory faults by returning - * a 0, else treat a fault like any other fault in the stub. - */ - -static unsigned char * -mem2hex(mem, buf, count, may_fault) - unsigned char *mem; - unsigned char *buf; - int count; - int may_fault; -{ - unsigned char ch; - - set_mem_fault_trap(may_fault); - - while (count-- > 0) - { - ch = *mem++; - if (mem_err) - return 0; - *buf++ = hexchars[ch >> 4]; - *buf++ = hexchars[ch & 0xf]; - } - - *buf = 0; - - set_mem_fault_trap(0); - - return buf; -} - -/* convert the hex array pointed to by buf into binary to be placed in mem - * return a pointer to the character AFTER the last byte written */ - -static char * -hex2mem(buf, mem, count, may_fault) - unsigned char *buf; - unsigned char *mem; - int count; - int may_fault; -{ - int i; - unsigned char ch; - - set_mem_fault_trap(may_fault); - - for (i=0; i<count; i++) - { - ch = hex(*buf++) << 4; - ch |= hex(*buf++); - *mem++ = ch; - if (mem_err) - return 0; - } - - set_mem_fault_trap(0); - - return mem; -} - -/* This table contains the mapping between SPARC hardware trap types, and - signals, which are primarily what GDB understands. It also indicates - which hardware traps we need to commandeer when initializing the stub. */ - -static struct hard_trap_info -{ - unsigned char tt; /* Trap type code for SPARClite */ - unsigned char signo; /* Signal that we map this trap into */ -} hard_trap_info[] = { - {1, SIGSEGV}, /* instruction access error */ - {2, SIGILL}, /* privileged instruction */ - {3, SIGILL}, /* illegal instruction */ - {4, SIGEMT}, /* fp disabled */ - {36, SIGEMT}, /* cp disabled */ - {7, SIGBUS}, /* mem address not aligned */ - {9, SIGSEGV}, /* data access exception */ - {10, SIGEMT}, /* tag overflow */ - {128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */ - {0, 0} /* Must be last */ -}; - -/* Set up exception handlers for tracing and breakpoints */ - -void -set_debug_traps() -{ - struct hard_trap_info *ht; - - for (ht = hard_trap_info; ht->tt && ht->signo; ht++) - exceptionHandler(ht->tt, trap_low); - - /* In case GDB is started before us, ack any packets (presumably - "$?#xx") sitting there. */ - - putDebugChar ('+'); - - initialized = 1; -} - -asm (" -! Trap handler for memory errors. This just sets mem_err to be non-zero. It -! assumes that %l1 is non-zero. This should be safe, as it is doubtful that -! 0 would ever contain code that could mem fault. This routine will skip -! past the faulting instruction after setting mem_err. - - .text - .align 4 - -_fltr_set_mem_err: - sethi %hi(_mem_err), %l0 - st %l1, [%l0 + %lo(_mem_err)] - jmpl %l2, %g0 - rett %l2+4 -"); - -static void -set_mem_fault_trap(enable) - int enable; -{ - extern void fltr_set_mem_err(); - mem_err = 0; - - if (enable) - exceptionHandler(9, fltr_set_mem_err); - else - exceptionHandler(9, trap_low); -} - -/* Convert the SPARC hardware trap type code to a unix signal number. */ - -static int -computeSignal(tt) - int tt; -{ - struct hard_trap_info *ht; - - for (ht = hard_trap_info; ht->tt && ht->signo; ht++) - if (ht->tt == tt) - return ht->signo; - - return SIGHUP; /* default for things we don't know about */ -} - -/* - * While we find nice hex chars, build an int. - * Return number of chars processed. - */ - -static int -hexToInt(char **ptr, int *intValue) -{ - int numChars = 0; - int hexValue; - - *intValue = 0; - - while (**ptr) - { - hexValue = hex(**ptr); - if (hexValue < 0) - break; - - *intValue = (*intValue << 4) | hexValue; - numChars ++; - - (*ptr)++; - } - - return (numChars); -} - -/* - * This function does all command procesing for interfacing to gdb. It - * returns 1 if you should skip the instruction at the trap address, 0 - * otherwise. - */ - -extern void breakinst(); - -static void -handle_exception (registers) - unsigned long *registers; -{ - int tt; /* Trap type */ - int sigval; - int addr; - int length; - char *ptr; - unsigned long *sp; - -/* First, we must force all of the windows to be spilled out */ - - asm(" save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - save %sp, -64, %sp - restore - restore - restore - restore - restore - restore - restore - restore -"); - - if (registers[PC] == (unsigned long)breakinst) - { - registers[PC] = registers[NPC]; - registers[NPC] += 4; - } - - sp = (unsigned long *)registers[SP]; - - tt = (registers[TBR] >> 4) & 0xff; - - /* reply to host that an exception has occurred */ - sigval = computeSignal(tt); - ptr = remcomOutBuffer; - - *ptr++ = 'T'; - *ptr++ = hexchars[sigval >> 4]; - *ptr++ = hexchars[sigval & 0xf]; - - *ptr++ = hexchars[PC >> 4]; - *ptr++ = hexchars[PC & 0xf]; - *ptr++ = ':'; - ptr = mem2hex((char *)®isters[PC], ptr, 4, 0); - *ptr++ = ';'; - - *ptr++ = hexchars[FP >> 4]; - *ptr++ = hexchars[FP & 0xf]; - *ptr++ = ':'; - ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */ - *ptr++ = ';'; - - *ptr++ = hexchars[SP >> 4]; - *ptr++ = hexchars[SP & 0xf]; - *ptr++ = ':'; - ptr = mem2hex((char *)&sp, ptr, 4, 0); - *ptr++ = ';'; - - *ptr++ = hexchars[NPC >> 4]; - *ptr++ = hexchars[NPC & 0xf]; - *ptr++ = ':'; - ptr = mem2hex((char *)®isters[NPC], ptr, 4, 0); - *ptr++ = ';'; - - *ptr++ = hexchars[O7 >> 4]; - *ptr++ = hexchars[O7 & 0xf]; - *ptr++ = ':'; - ptr = mem2hex((char *)®isters[O7], ptr, 4, 0); - *ptr++ = ';'; - - *ptr++ = 0; - - putpacket(remcomOutBuffer); - - while (1) - { - remcomOutBuffer[0] = 0; - - getpacket(remcomInBuffer); - switch (remcomInBuffer[0]) - { - case '?': - remcomOutBuffer[0] = 'S'; - remcomOutBuffer[1] = hexchars[sigval >> 4]; - remcomOutBuffer[2] = hexchars[sigval & 0xf]; - remcomOutBuffer[3] = 0; - break; - - case 'd': - /* toggle debug flag */ - break; - - case 'g': /* return the value of the CPU registers */ - { - ptr = remcomOutBuffer; - ptr = mem2hex((char *)registers, ptr, 16 * 4, 0); /* G & O regs */ - ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */ - memset(ptr, '0', 32 * 8); /* Floating point */ - mem2hex((char *)®isters[Y], - ptr + 32 * 4 * 2, - 8 * 4, - 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */ - } - break; - - case 'G': /* set the value of the CPU registers - return OK */ - { - unsigned long *newsp, psr; - - psr = registers[PSR]; - - ptr = &remcomInBuffer[1]; - hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */ - hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */ - hex2mem(ptr + 64 * 4 * 2, (char *)®isters[Y], - 8 * 4, 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */ - - /* See if the stack pointer has moved. If so, then copy the saved - locals and ins to the new location. This keeps the window - overflow and underflow routines happy. */ - - newsp = (unsigned long *)registers[SP]; - if (sp != newsp) - sp = memcpy(newsp, sp, 16 * 4); - - /* Don't allow CWP to be modified. */ - - if (psr != registers[PSR]) - registers[PSR] = (psr & 0x1f) | (registers[PSR] & ~0x1f); - - strcpy(remcomOutBuffer,"OK"); - } - break; - - case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ - /* Try to read %x,%x. */ - - ptr = &remcomInBuffer[1]; - - if (hexToInt(&ptr, &addr) - && *ptr++ == ',' - && hexToInt(&ptr, &length)) - { - if (mem2hex((char *)addr, remcomOutBuffer, length, 1)) - break; - - strcpy (remcomOutBuffer, "E03"); - } - else - strcpy(remcomOutBuffer,"E01"); - break; - - case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ - /* Try to read '%x,%x:'. */ - - ptr = &remcomInBuffer[1]; - - if (hexToInt(&ptr, &addr) - && *ptr++ == ',' - && hexToInt(&ptr, &length) - && *ptr++ == ':') - { - if (hex2mem(ptr, (char *)addr, length, 1)) - strcpy(remcomOutBuffer, "OK"); - else - strcpy(remcomOutBuffer, "E03"); - } - else - strcpy(remcomOutBuffer, "E02"); - break; - - case 'c': /* cAA..AA Continue at address AA..AA(optional) */ - /* try to read optional parameter, pc unchanged if no parm */ - - ptr = &remcomInBuffer[1]; - if (hexToInt(&ptr, &addr)) - { - registers[PC] = addr; - registers[NPC] = addr + 4; - } - -/* Need to flush the instruction cache here, as we may have deposited a - breakpoint, and the icache probably has no way of knowing that a data ref to - some location may have changed something that is in the instruction cache. - */ - - flush_i_cache(); - return; - - /* kill the program */ - case 'k' : /* do nothing */ - break; -#if 0 - case 't': /* Test feature */ - asm (" std %f30,[%sp]"); - break; -#endif - case 'r': /* Reset */ - asm ("call 0 - nop "); - break; - -#if 0 -Disabled until we can unscrew this properly - - case 'b': /* bBB... Set baud rate to BB... */ - { - int baudrate; - extern void set_timer_3(); - - ptr = &remcomInBuffer[1]; - if (!hexToInt(&ptr, &baudrate)) - { - strcpy(remcomOutBuffer,"B01"); - break; - } - - /* Convert baud rate to uart clock divider */ - switch (baudrate) - { - case 38400: - baudrate = 16; - break; - case 19200: - baudrate = 33; - break; - case 9600: - baudrate = 65; - break; - default: - strcpy(remcomOutBuffer,"B02"); - goto x1; - } - - putpacket("OK"); /* Ack before changing speed */ - set_timer_3(baudrate); /* Set it */ - } -x1: break; -#endif - } /* switch */ - - /* reply to the request */ - putpacket(remcomOutBuffer); - } -} - -/* This function will generate a breakpoint exception. It is used at the - beginning of a program to sync up with a debugger and can be used - otherwise as a quick means to stop program execution and "break" into - the debugger. */ - -void -breakpoint() -{ - if (!initialized) - return; - - asm(" .globl _breakinst - - _breakinst: ta 1 - "); -} |