From: Stan Shebs Date: Sun, 31 Jan 1999 21:46:19 +0000 (+0000) Subject: 1999-01-31 J.T. Conklin X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=3a70e50388b8dbc1817ff4d1407df46003952aff;p=binutils-gdb.git 1999-01-31 J.T. Conklin * i386-stub.c, m32r-stub.c, m68k-stub.c, sh-stub.c, sparc-stub.c, sparcl-stub, sparclet-stub.c: Change declaration of putDebugChar to include explicit void return type as per documentation. Fix up occasions where stubs erroneously checked return type. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 74f8bcc1aa9..586fd1a136d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +1999-01-31 J.T. Conklin + + * i386-stub.c, m32r-stub.c, m68k-stub.c, sh-stub.c, sparc-stub.c, + sparcl-stub, sparclet-stub.c: Change declaration of putDebugChar + to include explicit void return type as per documentation. Fix up + occasions where stubs erroneously checked return type. + Sun Jan 31 13:18:33 1999 Stan Shebs From J.T. Conklin : diff --git a/gdb/m32r-stub.c b/gdb/m32r-stub.c new file mode 100644 index 00000000000..1fed041b286 --- /dev/null +++ b/gdb/m32r-stub.c @@ -0,0 +1,1621 @@ +/**************************************************************************** + + 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 M32R by Michael Snyder, Cygnus Support. + * + * 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 external function exceptionHandler() is + * used to attach a specific handler to a specific M32R vector number. + * It should use the same privilege level it runs at. It should + * install it as an interrupt gate so that interrupts are masked + * while the handler runs. + * + * Because gdb will sometimes write to the stack area to execute function + * calls, this program cannot rely on using the supervisor stack so it + * uses it's own stack area reserved in the int array remcomStack. + * + ************* + * + * 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) + * + * All commands and responses are sent with a packet which includes a + * checksum. A packet consists of + * + * $#. + * + * where + * :: + * :: > + * + * 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 + * + ****************************************************************************/ + + +/************************************************************************ + * + * external low-level support routines + */ +extern void putDebugChar(); /* write a single character */ +extern int getDebugChar(); /* read and return a single char */ +extern void exceptionHandler(); /* assign an exception handler */ + +/***************************************************************************** + * BUFMAX defines the maximum number of characters in inbound/outbound buffers + * at least NUMREGBYTES*2 are needed for register packets + */ +#define BUFMAX 400 + +static char initialized; /* boolean flag. != 0 means we've been initialized */ + +int remote_debug; +/* debug > 0 prints ill-formed commands in valid packets & checksum errors */ + +static const char hexchars[]="0123456789abcdef"; + +#define NUMREGS 24 + +/* Number of bytes of registers. */ +#define NUMREGBYTES (NUMREGS * 4) +enum regnames { R0, R1, R2, R3, R4, R5, R6, R7, + R8, R9, R10, R11, R12, R13, R14, R15, + PSW, CBR, SPI, SPU, BPC, PC, ACCL, ACCH }; + +enum SYS_calls { + SYS_null, + SYS_exit, + SYS_open, + SYS_close, + SYS_read, + SYS_write, + SYS_lseek, + SYS_unlink, + SYS_getpid, + SYS_kill, + SYS_fstat, + SYS_sbrk, + SYS_fork, + SYS_execve, + SYS_wait4, + SYS_link, + SYS_chdir, + SYS_stat, + SYS_utime, + SYS_chown, + SYS_chmod, + SYS_time, + SYS_pipe }; + +static int registers[NUMREGS]; + +#define STACKSIZE 8096 +static char remcomInBuffer[BUFMAX]; +static char remcomOutBuffer[BUFMAX]; +static int remcomStack[STACKSIZE/sizeof(int)]; +static int* stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; + +static unsigned int save_vectors[18]; /* previous exception vectors */ + +/* Indicate to caller of mem2hex or hex2mem that there has been an error. */ +static volatile int mem_err = 0; + +/* Store the vector number here (since GDB only gets the signal + number through the usual means, and that's not very specific). */ +int gdb_m32r_vector = -1; + +#if 0 +#include "syscall.h" /* for SYS_exit, SYS_write etc. */ +#endif + +/* Global entry points: + */ + +extern void handle_exception(int); +extern void set_debug_traps(void); +extern void breakpoint(void); + +/* Local functions: + */ + +static int computeSignal(int); +static void putpacket(char *); +static void getpacket(char *); +static char *mem2hex(char *, char *, int, int); +static char *hex2mem(char *, char *, int, int); +static int hexToInt(char **, int *); +static void stash_registers(void); +static void restore_registers(void); +static int prepare_to_step(int); +static int finish_from_step(void); + +static void gdb_error(char *, char *); +static int gdb_putchar(int), gdb_puts(char *), gdb_write(char *, int); + +static char *strcpy (char *, const char *); +static int strlen (const char *); + +/* + * This function does all command procesing for interfacing to gdb. + */ + +void +handle_exception(int exceptionVector) +{ + int sigval; + int addr, length, i; + char * ptr; + char buf[16]; + + if (!finish_from_step()) + return; /* "false step": let the target continue */ + + gdb_m32r_vector = exceptionVector; + + if (remote_debug) + { + mem2hex((char *) &exceptionVector, buf, 4, 0); + gdb_error("Handle exception %s, ", buf); + mem2hex((char *) ®isters[PC], buf, 4, 0); + gdb_error("PC == 0x%s\n", buf); + } + + /* reply to host that an exception has occurred */ + sigval = computeSignal( exceptionVector ); + + ptr = remcomOutBuffer; + + *ptr++ = 'T'; /* notify gdb with signo, PC, FP and SP */ + *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); /* PC */ + *ptr++ = ';'; + + *ptr++ = hexchars[R13 >> 4]; + *ptr++ = hexchars[R13 & 0xf]; + *ptr++ = ':'; + ptr = mem2hex((char *)®isters[R13], ptr, 4, 0); /* FP */ + *ptr++ = ';'; + + *ptr++ = hexchars[R15 >> 4]; + *ptr++ = hexchars[R15 & 0xf]; + *ptr++ = ':'; + ptr = mem2hex((char *)®isters[R15], ptr, 4, 0); /* SP */ + *ptr++ = ';'; + *ptr++ = 0; + + if (exceptionVector == 0) /* simulated SYS call stuff */ + { + mem2hex((char *) ®isters[PC], buf, 4, 0); + switch (registers[R0]) { + case SYS_exit: + gdb_error("Target program has exited at %s\n", buf); + ptr = remcomOutBuffer; + *ptr++ = 'W'; + sigval = registers[R1] & 0xff; + *ptr++ = hexchars[sigval >> 4]; + *ptr++ = hexchars[sigval & 0xf]; + *ptr++ = 0; + break; + case SYS_open: + gdb_error("Target attempts SYS_open call at %s\n", buf); + break; + case SYS_close: + gdb_error("Target attempts SYS_close call at %s\n", buf); + break; + case SYS_read: + gdb_error("Target attempts SYS_read call at %s\n", buf); + break; + case SYS_write: + if (registers[R1] == 1 || /* write to stdout */ + registers[R1] == 2) /* write to stderr */ + { /* (we can do that) */ + registers[R0] = gdb_write((void *) registers[R2], registers[R3]); + return; + } + else + gdb_error("Target attempts SYS_write call at %s\n", buf); + break; + case SYS_lseek: + gdb_error("Target attempts SYS_lseek call at %s\n", buf); + break; + case SYS_unlink: + gdb_error("Target attempts SYS_unlink call at %s\n", buf); + break; + case SYS_getpid: + gdb_error("Target attempts SYS_getpid call at %s\n", buf); + break; + case SYS_kill: + gdb_error("Target attempts SYS_kill call at %s\n", buf); + break; + case SYS_fstat: + gdb_error("Target attempts SYS_fstat call at %s\n", buf); + break; + default: + gdb_error("Target attempts unknown SYS call at %s\n", buf); + break; + } + } + + putpacket(remcomOutBuffer); + + while (1==1) { + remcomOutBuffer[0] = 0; + getpacket(remcomInBuffer); + switch (remcomInBuffer[0]) { + default: /* Unknown code. Return an empty reply message. */ + break; + case 'R': + ptr = &remcomInBuffer[1]; + if (hexToInt (&ptr, &addr)) + registers[PC] = addr; + strcpy(remcomOutBuffer, "OK"); + break; + case '!': + strcpy(remcomOutBuffer, "OK"); + break; + case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */ + /* TRY TO READ '%x,%x:'. IF SUCCEED, SET PTR = 0 */ + ptr = &remcomInBuffer[1]; + if (hexToInt(&ptr,&addr)) + if (*(ptr++) == ',') + if (hexToInt(&ptr,&length)) + if (*(ptr++) == ':') + { + mem_err = 0; + hex2mem(ptr, (char*) addr, length, 1); + if (mem_err) { + strcpy (remcomOutBuffer, "E03"); + gdb_error ("memory fault", ""); + } else { + strcpy(remcomOutBuffer,"OK"); + } + ptr = 0; + } + if (ptr) + { + strcpy(remcomOutBuffer,"E02"); + gdb_error("malformed write memory command: %s", + remcomInBuffer); + } + break; + case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ + /* TRY TO READ %x,%x. IF SUCCEED, SET PTR = 0 */ + ptr = &remcomInBuffer[1]; + if (hexToInt(&ptr,&addr)) + if (*(ptr++) == ',') + if (hexToInt(&ptr,&length)) + { + ptr = 0; + mem_err = 0; + mem2hex((char*) addr, remcomOutBuffer, length, 1); + if (mem_err) { + strcpy (remcomOutBuffer, "E03"); + gdb_error ("memory fault", ""); + } + } + if (ptr) + { + strcpy(remcomOutBuffer,"E01"); + gdb_error("malformed read memory command: %s", + remcomInBuffer); + } + break; + case '?': + remcomOutBuffer[0] = 'S'; + remcomOutBuffer[1] = hexchars[sigval >> 4]; + remcomOutBuffer[2] = hexchars[sigval % 16]; + remcomOutBuffer[3] = 0; + break; + case 'd': + remote_debug = !(remote_debug); /* toggle debug flag */ + break; + case 'g': /* return the value of the CPU registers */ + mem2hex((char*) registers, remcomOutBuffer, NUMREGBYTES, 0); + break; + case 'P': /* set the value of a single CPU register - return OK */ + { + int regno; + + ptr = &remcomInBuffer[1]; + if (hexToInt (&ptr, ®no) && *ptr++ == '=') + if (regno >= 0 && regno < NUMREGS) + { + int stackmode; + + hex2mem (ptr, (char *) ®isters[regno], 4, 0); + /* + * Since we just changed a single CPU register, let's + * make sure to keep the several stack pointers consistant. + */ + stackmode = registers[PSW] & 0x80; + if (regno == R15) /* stack pointer changed */ + { /* need to change SPI or SPU */ + if (stackmode == 0) + registers[SPI] = registers[R15]; + else + registers[SPU] = registers[R15]; + } + else if (regno == SPU) /* "user" stack pointer changed */ + { + if (stackmode != 0) /* stack in user mode: copy SP */ + registers[R15] = registers[SPU]; + } + else if (regno == SPI) /* "interrupt" stack pointer changed */ + { + if (stackmode == 0) /* stack in interrupt mode: copy SP */ + registers[R15] = registers[SPI]; + } + else if (regno == PSW) /* stack mode may have changed! */ + { /* force SP to either SPU or SPI */ + if (stackmode == 0) /* stack in user mode */ + registers[R15] = registers[SPI]; + else /* stack in interrupt mode */ + registers[R15] = registers[SPU]; + } + strcpy (remcomOutBuffer, "OK"); + break; + } + strcpy (remcomOutBuffer, "P01"); + break; + } + case 'G': /* set the value of the CPU registers - return OK */ + hex2mem(&remcomInBuffer[1], (char*) registers, NUMREGBYTES, 0); + strcpy(remcomOutBuffer,"OK"); + break; + case 's': /* sAA..AA Step one instruction from AA..AA(optional) */ + case 'c': /* cAA..AA Continue from address AA..AA(optional) */ + /* try to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (hexToInt(&ptr,&addr)) + registers[ PC ] = addr; + + if (remcomInBuffer[0] == 's') /* single-stepping */ + { + if (!prepare_to_step(0)) /* set up for single-step */ + { + /* prepare_to_step has already emulated the target insn: + Send SIGTRAP to gdb, don't resume the target at all. */ + ptr = remcomOutBuffer; + *ptr++ = 'T'; /* Simulate stopping with SIGTRAP */ + *ptr++ = '0'; + *ptr++ = '5'; + + *ptr++ = hexchars[PC >> 4]; /* send PC */ + *ptr++ = hexchars[PC & 0xf]; + *ptr++ = ':'; + ptr = mem2hex((char *)®isters[PC], ptr, 4, 0); + *ptr++ = ';'; + + *ptr++ = hexchars[R13 >> 4]; /* send FP */ + *ptr++ = hexchars[R13 & 0xf]; + *ptr++ = ':'; + ptr = mem2hex((char *)®isters[R13], ptr, 4, 0); + *ptr++ = ';'; + + *ptr++ = hexchars[R15 >> 4]; /* send SP */ + *ptr++ = hexchars[R15 & 0xf]; + *ptr++ = ':'; + ptr = mem2hex((char *)®isters[R15], ptr, 4, 0); + *ptr++ = ';'; + *ptr++ = 0; + + break; + } + } + else /* continuing, not single-stepping */ + { + /* OK, about to do a "continue". First check to see if the + target pc is on an odd boundary (second instruction in the + word). If so, we must do a single-step first, because + ya can't jump or return back to an odd boundary! */ + if ((registers[PC] & 2) != 0) + prepare_to_step(1); + } + return; + + case 'D': /* Detach */ + /* I am interpreting this to mean, release the board from control + by the remote stub. To do this, I am restoring the original + (or at least previous) exception vectors. + */ + for (i = 0; i < 18; i++) + exceptionHandler (i, save_vectors[i]); + putpacket ("OK"); + return; /* continue the inferior */ + + case 'k': /* kill the program */ + continue; + } /* switch */ + + /* reply to the request */ + putpacket(remcomOutBuffer); + } +} + +static int +hex(ch) + 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 $# */ + +static void +getpacket(buffer) + char * buffer; +{ + unsigned char checksum; + unsigned char xmitcsum; + int i; + int count; + char ch; + + do { + /* wait around for the start character, ignore all other characters */ + while ((ch = (getDebugChar() & 0x7f)) != '$'); + 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; + } + buffer[count] = 0; + + if (ch == '#') { + xmitcsum = hex(getDebugChar() & 0x7f) << 4; + xmitcsum += hex(getDebugChar() & 0x7f); + if (checksum != xmitcsum) { + if (remote_debug) { + char buf[16]; + + mem2hex((char *) &checksum, buf, 4, 0); + gdb_error("Bad checksum: my count = %s, ", buf); + mem2hex((char *) &xmitcsum, buf, 4, 0); + gdb_error("sent count = %s\n", buf); + gdb_error(" -- Bad buffer: \"%s\"\n", buffer); + } + + 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) + char * buffer; +{ + unsigned char checksum; + int count; + char ch; + + /* $#. */ + do { + putDebugChar('$'); + checksum = 0; + count = 0; + + while (ch=buffer[count]) { + putDebugChar(ch); + checksum += ch; + count += 1; + } + putDebugChar('#'); + putDebugChar(hexchars[checksum >> 4]); + putDebugChar(hexchars[checksum % 16]); + } while ((getDebugChar() & 0x7f) != '+'); +} + +/* Address of a routine to RTE to if we get a memory fault. */ + +static void (*volatile mem_fault_routine)() = 0; + +static void +set_mem_err () +{ + mem_err = 1; +} + +/* Check the address for safe access ranges. As currently defined, + this routine will reject the "expansion bus" address range(s). + To make those ranges useable, someone must implement code to detect + whether there's anything connected to the expansion bus. */ + +static int +mem_safe (addr) + char *addr; +{ +#define BAD_RANGE_ONE_START ((char *) 0x600000) +#define BAD_RANGE_ONE_END ((char *) 0xa00000) +#define BAD_RANGE_TWO_START ((char *) 0xff680000) +#define BAD_RANGE_TWO_END ((char *) 0xff800000) + + if (addr < BAD_RANGE_ONE_START) return 1; /* safe */ + if (addr < BAD_RANGE_ONE_END) return 0; /* unsafe */ + if (addr < BAD_RANGE_TWO_START) return 1; /* safe */ + if (addr < BAD_RANGE_TWO_END) return 0; /* unsafe */ +} + +/* These are separate functions so that they are so short and sweet + that the compiler won't save any registers (if there is a fault + to mem_fault, they won't get restored, so there better not be any + saved). */ +static int +get_char (addr) + char *addr; +{ +#if 1 + if (mem_fault_routine && !mem_safe(addr)) + { + mem_fault_routine (); + return 0; + } +#endif + return *addr; +} + +static void +set_char (addr, val) + char *addr; + int val; +{ +#if 1 + if (mem_fault_routine && !mem_safe (addr)) + { + mem_fault_routine (); + return; + } +#endif + *addr = val; +} + +/* Convert the memory pointed to by mem into hex, placing result in buf. + Return a pointer to the last char put in buf (null). + If MAY_FAULT is non-zero, then we should set mem_err in response to + a fault; if zero treat a fault like any other fault in the stub. */ + +static char * +mem2hex(mem, buf, count, may_fault) + char* mem; + char* buf; + int count; + int may_fault; +{ + int i; + unsigned char ch; + + if (may_fault) + mem_fault_routine = set_mem_err; + for (i=0;i> 4]; + *buf++ = hexchars[ch % 16]; + } + *buf = 0; + if (may_fault) + mem_fault_routine = 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) + char* buf; + char* mem; + int count; + int may_fault; +{ + int i; + unsigned char ch; + + if (may_fault) + mem_fault_routine = set_mem_err; + for (i=0;i=0) + { + *intValue = (*intValue <<4) | hexValue; + numChars ++; + } + else + break; + (*ptr)++; + } + return (numChars); +} + +/* + Table of branch instructions: + + 10B6 RTE return from trap or exception + 1FCr JMP jump + 1ECr JL jump and link + 7Fxx BRA branch + FFxxxxxx BRA branch (long) + B09rxxxx BNEZ branch not-equal-zero + Br1rxxxx BNE branch not-equal + 7Dxx BNC branch not-condition + FDxxxxxx BNC branch not-condition (long) + B0Arxxxx BLTZ branch less-than-zero + B0Crxxxx BLEZ branch less-equal-zero + 7Exx BL branch and link + FExxxxxx BL branch and link (long) + B0Drxxxx BGTZ branch greater-than-zero + B0Brxxxx BGEZ branch greater-equal-zero + B08rxxxx BEQZ branch equal-zero + Br0rxxxx BEQ branch equal + 7Cxx BC branch condition + FCxxxxxx BC branch condition (long) + */ + +static int +isShortBranch(instr) + unsigned char *instr; +{ + char instr0 = instr[0] & 0x7F; /* mask off high bit */ + + if (instr0 == 0x10 && instr[1] == 0xB6) /* RTE */ + return 1; /* return from trap or exception */ + + if (instr0 == 0x1E || instr0 == 0x1F) /* JL or JMP */ + if ((instr[1] & 0xF0) == 0xC0) + return 2; /* jump thru a register */ + + if (instr0 == 0x7C || instr0 == 0x7D || /* BC, BNC, BL, BRA */ + instr0 == 0x7E || instr0 == 0x7F) + return 3; /* eight bit PC offset */ + + return 0; +} + +static int +isLongBranch(instr) + unsigned char *instr; +{ + if (instr[0] == 0xFC || instr[0] == 0xFD || /* BRA, BNC, BL, BC */ + instr[0] == 0xFE || instr[0] == 0xFF) /* 24 bit relative */ + return 4; + if ((instr[0] & 0xF0) == 0xB0) /* 16 bit relative */ + { + if ((instr[1] & 0xF0) == 0x00 || /* BNE, BEQ */ + (instr[1] & 0xF0) == 0x10) + return 5; + if (instr[0] == 0xB0) /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ, BEQZ */ + if ((instr[1] & 0xF0) == 0x80 || (instr[1] & 0xF0) == 0x90 || + (instr[1] & 0xF0) == 0xA0 || (instr[1] & 0xF0) == 0xB0 || + (instr[1] & 0xF0) == 0xC0 || (instr[1] & 0xF0) == 0xD0) + return 6; + } + return 0; +} + +/* if address is NOT on a 4-byte boundary, or high-bit of instr is zero, + then it's a 2-byte instruction, else it's a 4-byte instruction. */ + +#define INSTRUCTION_SIZE(addr) \ + ((((int) addr & 2) || (((unsigned char *) addr)[0] & 0x80) == 0) ? 2 : 4) + +static int +isBranch(instr) + unsigned char *instr; +{ + if (INSTRUCTION_SIZE(instr) == 2) + return isShortBranch(instr); + else + return isLongBranch(instr); +} + +static int +willBranch(instr, branchCode) + unsigned char *instr; +{ + switch (branchCode) + { + case 0: return 0; /* not a branch */ + case 1: return 1; /* RTE */ + case 2: return 1; /* JL or JMP */ + case 3: /* BC, BNC, BL, BRA (short) */ + case 4: /* BC, BNC, BL, BRA (long) */ + switch (instr[0] & 0x0F) + { + case 0xC: /* Branch if Condition Register */ + return (registers[CBR] != 0); + case 0xD: /* Branch if NOT Condition Register */ + return (registers[CBR] == 0); + case 0xE: /* Branch and Link */ + case 0xF: /* Branch (unconditional) */ + return 1; + default: /* oops? */ + return 0; + } + case 5: /* BNE, BEQ */ + switch (instr[1] & 0xF0) + { + case 0x00: /* Branch if r1 equal to r2 */ + return (registers[instr[0] & 0x0F] == registers[instr[1] & 0x0F]); + case 0x10: /* Branch if r1 NOT equal to r2 */ + return (registers[instr[0] & 0x0F] != registers[instr[1] & 0x0F]); + default: /* oops? */ + return 0; + } + case 6: /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ */ + switch (instr[1] & 0xF0) + { + case 0x80: /* Branch if reg equal to zero */ + return (registers[instr[1] & 0x0F] == 0); + case 0x90: /* Branch if reg NOT equal to zero */ + return (registers[instr[1] & 0x0F] != 0); + case 0xA0: /* Branch if reg less than zero */ + return (registers[instr[1] & 0x0F] < 0); + case 0xB0: /* Branch if reg greater or equal to zero */ + return (registers[instr[1] & 0x0F] >= 0); + case 0xC0: /* Branch if reg less than or equal to zero */ + return (registers[instr[1] & 0x0F] <= 0); + case 0xD0: /* Branch if reg greater than zero */ + return (registers[instr[1] & 0x0F] > 0); + default: /* oops? */ + return 0; + } + default: /* oops? */ + return 0; + } +} + +static int +branchDestination(instr, branchCode) + unsigned char *instr; +{ + switch (branchCode) { + default: + case 0: /* not a branch */ + return 0; + case 1: /* RTE */ + return registers[BPC] & ~3; /* pop BPC into PC */ + case 2: /* JL or JMP */ + return registers[instr[1] & 0x0F] & ~3; /* jump thru a register */ + case 3: /* BC, BNC, BL, BRA (short, 8-bit relative offset) */ + return (((int) instr) & ~3) + ((char) instr[1] << 2); + case 4: /* BC, BNC, BL, BRA (long, 24-bit relative offset) */ + return ((int) instr + + ((((char) instr[1] << 16) | (instr[2] << 8) | (instr[3])) << 2)); + case 5: /* BNE, BEQ (16-bit relative offset) */ + case 6: /* BNEZ, BLTZ, BLEZ, BGTZ, BGEZ ,BEQZ (ditto) */ + return ((int) instr + ((((char) instr[2] << 8) | (instr[3])) << 2)); + } + + /* An explanatory note: in the last three return expressions, I have + cast the most-significant byte of the return offset to char. + What this accomplishes is sign extension. If the other + less-significant bytes were signed as well, they would get sign + extended too and, if negative, their leading bits would clobber + the bits of the more-significant bytes ahead of them. There are + other ways I could have done this, but sign extension from + odd-sized integers is always a pain. */ +} + +static void +branchSideEffects(instr, branchCode) + char *instr; + int branchCode; +{ + switch (branchCode) + { + case 1: /* RTE */ + return; /* I this is already handled... */ + case 2: /* JL (or JMP) */ + case 3: /* BL (or BC, BNC, BRA) */ + case 4: + if ((instr[0] & 0x0F) == 0x0E) /* branch/jump and link */ + registers[R14] = (registers[PC] & ~3) + 4; + return; + default: /* any other branch has no side effects */ + return; + } +} + +static struct STEPPING_CONTEXT { + int stepping; /* true when we've started a single-step */ + unsigned long target_addr; /* the instr we're trying to execute */ + unsigned long target_size; /* the size of the target instr */ + unsigned long noop_addr; /* where we've inserted a no-op, if any */ + unsigned long trap1_addr; /* the trap following the target instr */ + unsigned long trap2_addr; /* the trap at a branch destination, if any */ + unsigned short noop_save; /* instruction overwritten by our no-op */ + unsigned short trap1_save; /* instruction overwritten by trap1 */ + unsigned short trap2_save; /* instruction overwritten by trap2 */ + unsigned short continue_p; /* true if NOT returning to gdb after step */ +} stepping; + +/* Function: prepare_to_step + Called from handle_exception to prepare the user program to single-step. + Places a trap instruction after the target instruction, with special + extra handling for branch instructions and for instructions in the + second half-word of a word. + + Returns: True if we should actually execute the instruction; + False if we are going to emulate executing the instruction, + in which case we simply report to GDB that the instruction + has already been executed. */ + +#define TRAP1 0x10f1; /* trap #1 instruction */ +#define NOOP 0x7000; /* noop instruction */ + +static unsigned short trap1 = TRAP1; +static unsigned short noop = NOOP; + +static int +prepare_to_step(continue_p) + int continue_p; /* if this isn't REALLY a single-step (see below) */ +{ + unsigned long pc = registers[PC]; + int branchCode = isBranch((char *) pc); + char *p; + + /* zero out the stepping context + (paranoia -- it should already be zeroed) */ + for (p = (char *) &stepping; + p < ((char *) &stepping) + sizeof(stepping); + p++) + *p = 0; + + if (branchCode != 0) /* next instruction is a branch */ + { + branchSideEffects((char *) pc, branchCode); + if (willBranch((char *)pc, branchCode)) + registers[PC] = branchDestination((char *) pc, branchCode); + else + registers[PC] = pc + INSTRUCTION_SIZE(pc); + return 0; /* branch "executed" -- just notify GDB */ + } + else if (((int) pc & 2) != 0) /* "second-slot" instruction */ + { + /* insert no-op before pc */ + stepping.noop_addr = pc - 2; + stepping.noop_save = *(unsigned short *) stepping.noop_addr; + *(unsigned short *) stepping.noop_addr = noop; + /* insert trap after pc */ + stepping.trap1_addr = pc + 2; + stepping.trap1_save = *(unsigned short *) stepping.trap1_addr; + *(unsigned short *) stepping.trap1_addr = trap1; + } + else /* "first-slot" instruction */ + { + /* insert trap after pc */ + stepping.trap1_addr = pc + INSTRUCTION_SIZE(pc); + stepping.trap1_save = *(unsigned short *) stepping.trap1_addr; + *(unsigned short *) stepping.trap1_addr = trap1; + } + /* "continue_p" means that we are actually doing a continue, and not + being requested to single-step by GDB. Sometimes we have to do + one single-step before continuing, because the PC is on a half-word + boundary. There's no way to simply resume at such an address. */ + stepping.continue_p = continue_p; + stepping.stepping = 1; /* starting a single-step */ + return 1; +} + +/* Function: finish_from_step + Called from handle_exception to finish up when the user program + returns from a single-step. Replaces the instructions that had + been overwritten by traps or no-ops, + + Returns: True if we should notify GDB that the target stopped. + False if we only single-stepped because we had to before we + could continue (ie. we were trying to continue at a + half-word boundary). In that case don't notify GDB: + just "continue continuing". */ + +static int +finish_from_step() +{ + if (stepping.stepping) /* anything to do? */ + { + int continue_p = stepping.continue_p; + char *p; + + if (stepping.noop_addr) /* replace instr "under" our no-op */ + *(unsigned short *) stepping.noop_addr = stepping.noop_save; + if (stepping.trap1_addr) /* replace instr "under" our trap */ + *(unsigned short *) stepping.trap1_addr = stepping.trap1_save; + if (stepping.trap2_addr) /* ditto our other trap, if any */ + *(unsigned short *) stepping.trap2_addr = stepping.trap2_save; + + for (p = (char *) &stepping; /* zero out the stepping context */ + p < ((char *) &stepping) + sizeof(stepping); + p++) + *p = 0; + + return !(continue_p); + } + else /* we didn't single-step, therefore this must be a legitimate stop */ + return 1; +} + +struct PSWreg { /* separate out the bit flags in the PSW register */ + int pad1 : 16; + int bsm : 1; + int bie : 1; + int pad2 : 5; + int bc : 1; + int sm : 1; + int ie : 1; + int pad3 : 5; + int c : 1; +} *psw; + +/* Upon entry the value for LR to save has been pushed. + We unpush that so that the value for the stack pointer saved is correct. + Upon entry, all other registers are assumed to have not been modified + since the interrupt/trap occured. */ + +asm (" +stash_registers: + push r0 + push r1 + seth r1, #shigh(registers) + add3 r1, r1, #low(registers) + pop r0 ; r1 + st r0, @(4,r1) + pop r0 ; r0 + st r0, @r1 + addi r1, #4 ; only add 4 as subsequent saves are `pre inc' + st r2, @+r1 + st r3, @+r1 + st r4, @+r1 + st r5, @+r1 + st r6, @+r1 + st r7, @+r1 + st r8, @+r1 + st r9, @+r1 + st r10, @+r1 + st r11, @+r1 + st r12, @+r1 + st r13, @+r1 ; fp + pop r0 ; lr (r14) + st r0, @+r1 + st sp, @+r1 ; sp contains right value at this point + mvfc r0, cr0 + st r0, @+r1 ; cr0 == PSW + mvfc r0, cr1 + st r0, @+r1 ; cr1 == CBR + mvfc r0, cr2 + st r0, @+r1 ; cr2 == SPI + mvfc r0, cr3 + st r0, @+r1 ; cr3 == SPU + mvfc r0, cr6 + st r0, @+r1 ; cr6 == BPC + st r0, @+r1 ; PC == BPC + mvfaclo r0 + st r0, @+r1 ; ACCL + mvfachi r0 + st r0, @+r1 ; ACCH + jmp lr"); + +/* C routine to clean up what stash_registers did. + It is called after calling stash_registers. + This is separate from stash_registers as we want to do this in C + but doing stash_registers in C isn't straightforward. */ + +static void +cleanup_stash () +{ + psw = (struct PSWreg *) ®isters[PSW]; /* fields of PSW register */ + psw->sm = psw->bsm; /* fix up pre-trap values of psw fields */ + psw->ie = psw->bie; + psw->c = psw->bc; + registers[CBR] = psw->bc; /* fix up pre-trap "C" register */ + +#if 0 /* FIXME: Was in previous version. Necessary? + (Remember that we use the "rte" insn to return from the + trap/interrupt so the values of bsm, bie, bc are important. */ + psw->bsm = psw->bie = psw->bc = 0; /* zero post-trap values */ +#endif + + /* FIXME: Copied from previous version. This can probably be deleted + since methinks stash_registers has already done this. */ + registers[PC] = registers[BPC]; /* pre-trap PC */ + + /* FIXME: Copied from previous version. Necessary? */ + if (psw->sm) /* copy R15 into (psw->sm ? SPU : SPI) */ + registers[SPU] = registers[R15]; + else + registers[SPI] = registers[R15]; +} + +asm (" +restore_and_return: + seth r0, #shigh(registers+8) + add3 r0, r0, #low(registers+8) + ld r2, @r0+ ; restore r2 + ld r3, @r0+ ; restore r3 + ld r4, @r0+ ; restore r4 + ld r5, @r0+ ; restore r5 + ld r6, @r0+ ; restore r6 + ld r7, @r0+ ; restore r7 + ld r8, @r0+ ; restore r8 + ld r9, @r0+ ; restore r9 + ld r10, @r0+ ; restore r10 + ld r11, @r0+ ; restore r11 + ld r12, @r0+ ; restore r12 + ld r13, @r0+ ; restore r13 + ld r14, @r0+ ; restore r14 + ld r15, @r0+ ; restore r15 + ld r1, @r0+ ; restore cr0 == PSW + mvtc r1, cr0 + ld r1, @r0+ ; restore cr1 == CBR (no-op, because it's read only) + mvtc r1, cr1 + ld r1, @r0+ ; restore cr2 == SPI + mvtc r1, cr2 + ld r1, @r0+ ; restore cr3 == SPU + mvtc r1, cr3 + addi r0, #4 ; skip BPC + ld r1, @r0+ ; restore cr6 (BPC) == PC + mvtc r1, cr6 + ld r1, @r0+ ; restore ACCL + mvtaclo r1 + ld r1, @r0+ ; restore ACCH + mvtachi r1 + seth r0, #shigh(registers) + add3 r0, r0, #low(registers) + ld r1, @(4,r0) ; restore r1 + ld r0, @r0 ; restore r0 + rte"); + +/* General trap handler, called after the registers have been stashed. + NUM is the trap/exception number. */ + +static void +process_exception (num) + int num; +{ + cleanup_stash (); + asm volatile (" + seth r1, #shigh(stackPtr) + add3 r1, r1, #low(stackPtr) + ld r15, @r1 ; setup local stack (protect user stack) + mv r0, %0 + bl handle_exception + bl restore_and_return" + : : "r" (num) : "r0", "r1"); +} + +void _catchException0 (); + +asm (" +_catchException0: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #0 + bl process_exception"); + +void _catchException1 (); + +asm (" +_catchException1: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + bl cleanup_stash + seth r1, #shigh(stackPtr) + add3 r1, r1, #low(stackPtr) + ld r15, @r1 ; setup local stack (protect user stack) + seth r1, #shigh(registers + 21*4) ; PC + add3 r1, r1, #low(registers + 21*4) + ld r0, @r1 + addi r0, #-4 ; back up PC for breakpoint trap. + st r0, @r1 ; FIXME: what about bp in right slot? + ldi r0, #1 + bl handle_exception + bl restore_and_return"); + +void _catchException2 (); + +asm (" +_catchException2: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #2 + bl process_exception"); + +void _catchException3 (); + +asm (" +_catchException3: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #3 + bl process_exception"); + +void _catchException4 (); + +asm (" +_catchException4: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #4 + bl process_exception"); + +void _catchException5 (); + +asm (" +_catchException5: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #5 + bl process_exception"); + +void _catchException6 (); + +asm (" +_catchException6: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #6 + bl process_exception"); + +void _catchException7 (); + +asm (" +_catchException7: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #7 + bl process_exception"); + +void _catchException8 (); + +asm (" +_catchException8: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #8 + bl process_exception"); + +void _catchException9 (); + +asm (" +_catchException9: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #9 + bl process_exception"); + +void _catchException10 (); + +asm (" +_catchException10: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #10 + bl process_exception"); + +void _catchException11 (); + +asm (" +_catchException11: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #11 + bl process_exception"); + +void _catchException12 (); + +asm (" +_catchException12: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #12 + bl process_exception"); + +void _catchException13 (); + +asm (" +_catchException13: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #13 + bl process_exception"); + +void _catchException14 (); + +asm (" +_catchException14: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #14 + bl process_exception"); + +void _catchException15 (); + +asm (" +_catchException15: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #15 + bl process_exception"); + +void _catchException16 (); + +asm (" +_catchException16: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #16 + bl process_exception"); + +void _catchException17 (); + +asm (" +_catchException17: + push lr + bl stash_registers + ; Note that at this point the pushed value of `lr' has been popped + ldi r0, #17 + bl process_exception"); + + +/* this function is used to set up exception handlers for tracing and + breakpoints */ +void +set_debug_traps() +{ + /* extern void remcomHandler(); */ + int i; + + for (i = 0; i < 18; i++) /* keep a copy of old vectors */ + if (save_vectors[i] == 0) /* only copy them the first time */ + save_vectors[i] = getExceptionHandler (i); + + stackPtr = &remcomStack[STACKSIZE/sizeof(int) - 1]; + + exceptionHandler (0, _catchException0); + exceptionHandler (1, _catchException1); + exceptionHandler (2, _catchException2); + exceptionHandler (3, _catchException3); + exceptionHandler (4, _catchException4); + exceptionHandler (5, _catchException5); + exceptionHandler (6, _catchException6); + exceptionHandler (7, _catchException7); + exceptionHandler (8, _catchException8); + exceptionHandler (9, _catchException9); + exceptionHandler (10, _catchException10); + exceptionHandler (11, _catchException11); + exceptionHandler (12, _catchException12); + exceptionHandler (13, _catchException13); + exceptionHandler (14, _catchException14); + exceptionHandler (15, _catchException15); + exceptionHandler (16, _catchException16); + /* exceptionHandler (17, _catchException17); */ + + /* In case GDB is started before us, ack any packets (presumably + "$?#xx") sitting there. */ + putDebugChar ('+'); + + initialized = 1; +} + +/* 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. */ + +#define BREAKPOINT() asm volatile (" trap #2"); + +void +breakpoint() +{ + if (initialized) + BREAKPOINT(); +} + +/* STDOUT section: + Stuff pertaining to simulating stdout by sending chars to gdb to be echoed. + Functions: gdb_putchar(char ch) + gdb_puts(char *str) + gdb_write(char *str, int len) + gdb_error(char *format, char *parm) + */ + +/* Function: gdb_putchar(int) + Make gdb write a char to stdout. + Returns: the char */ + +static int +gdb_putchar(ch) + int ch; +{ + char buf[4]; + + buf[0] = 'O'; + buf[1] = hexchars[ch >> 4]; + buf[2] = hexchars[ch & 0x0F]; + buf[3] = 0; + putpacket(buf); + return ch; +} + +/* Function: gdb_write(char *, int) + Make gdb write n bytes to stdout (not assumed to be null-terminated). + Returns: number of bytes written */ + +static int +gdb_write(data, len) + char *data; + int len; +{ + char *buf, *cpy; + int i; + + buf = remcomOutBuffer; + buf[0] = 'O'; + i = 0; + while (i < len) + { + for (cpy = buf+1; + i < len && cpy < buf + sizeof(remcomOutBuffer) - 3; + i++) + { + *cpy++ = hexchars[data[i] >> 4]; + *cpy++ = hexchars[data[i] & 0x0F]; + } + *cpy = 0; + putpacket(buf); + } + return len; +} + +/* Function: gdb_puts(char *) + Make gdb write a null-terminated string to stdout. + Returns: the length of the string */ + +static int +gdb_puts(str) + char *str; +{ + return gdb_write(str, strlen(str)); +} + +/* Function: gdb_error(char *, char *) + Send an error message to gdb's stdout. + First string may have 1 (one) optional "%s" in it, which + will cause the optional second string to be inserted. */ + +static void +gdb_error(format, parm) + char * format; + char * parm; +{ + char buf[400], *cpy; + int len; + + if (remote_debug) + { + if (format && *format) + len = strlen(format); + else + return; /* empty input */ + + if (parm && *parm) + len += strlen(parm); + + for (cpy = buf; *format; ) + { + if (format[0] == '%' && format[1] == 's') /* include second string */ + { + format += 2; /* advance two chars instead of just one */ + while (parm && *parm) + *cpy++ = *parm++; + } + else + *cpy++ = *format++; + } + *cpy = '\0'; + gdb_puts(buf); + } +} + +static char * +strcpy (char *dest, const char *src) +{ + char *ret = dest; + + if (dest && src) + { + while (*src) + *dest++ = *src++; + *dest = 0; + } + return ret; +} + +static int +strlen (const char *src) +{ + int ret; + + for (ret = 0; *src; src++) + ret++; + + return ret; +} + +#if 0 +void exit (code) + int code; +{ + _exit (code); +} + +int atexit (void *p) +{ + return 0; +} + +void abort (void) +{ + _exit (1); +} +#endif diff --git a/gdb/sh-stub.c b/gdb/sh-stub.c index beb87085c7e..a036cff6062 100644 --- a/gdb/sh-stub.c +++ b/gdb/sh-stub.c @@ -202,8 +202,7 @@ static int computeSignal (int exceptionVector); static void handle_exception (int exceptionVector); void init_serial(); - -int putDebugChar (char); +void putDebugChar (char); char getDebugChar (void); /* These are in the file but in asm statements so the compiler can't see them */ @@ -1457,8 +1456,6 @@ exceptions() #define BPS 32 /* 9600 for 10 Mhz */ #endif -char getDebugChar (void); -int putDebugChar (char); void handleError (char theSSR); void @@ -1531,7 +1528,7 @@ putDebugCharReady() return (SSR1 & SCI_TDRE); } -int +void putDebugChar (char ch) { while (!putDebugCharReady()) @@ -1542,7 +1539,6 @@ putDebugChar (char ch) */ TDR1 = ch; SSR1 &= ~SCI_TDRE; - return 1; } void diff --git a/gdb/sparc-stub.c b/gdb/sparc-stub.c index 1f04f31955f..7da65c21080 100644 --- a/gdb/sparc-stub.c +++ b/gdb/sparc-stub.c @@ -92,8 +92,8 @@ * external low-level support routines */ -extern putDebugChar(); /* write a single character */ -extern getDebugChar(); /* read and return a single char */ +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*/ @@ -371,8 +371,7 @@ putpacket(buffer) while (ch = buffer[count]) { - if (! putDebugChar(ch)) - return; + putDebugChar(ch); checksum += ch; count += 1; } diff --git a/gdb/sparclet-stub.c b/gdb/sparclet-stub.c index a4621283040..ecf670b1152 100644 --- a/gdb/sparclet-stub.c +++ b/gdb/sparclet-stub.c @@ -95,8 +95,8 @@ * external low-level support routines */ -extern putDebugChar(); /* write a single character */ -extern getDebugChar(); /* read and return a single char */ +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*/ @@ -534,8 +534,7 @@ putpacket(buffer) while (ch = buffer[count]) { - if (! putDebugChar(ch)) - return; + putDebugChar(ch); checksum += ch; count += 1; }