--- /dev/null
+/****************************************************************************
+
+ 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.
+ *
+ * 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)
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <signal.h>
+#include <memory.h>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+
+extern putDebugChar(); /* write a single character */
+extern 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; /* boolean flag. != 0 means we've been initialized */
+
+static void set_mem_fault_trap();
+
+int remote_debug;
+/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
+
+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 };
+
+static unsigned long registers[NUMREGS] __attribute__ ((aligned (8)));
+
+/*************************** ASSEMBLY CODE MACROS *************************/
+/* */
+
+#define BREAKPOINT() asm(" ta 1");
+
+extern unsigned long rdtbr();
+
+asm("
+ .text
+!
+! FUNCTION
+! _chk4ovflo
+!
+! DESCRIPTION
+! This code is branched to before each trap (except reset,
+! _win_unf, and _win_ovf) handler.
+! It checks to see if we've moved into the invalid window
+! and performs fixup ala _win_ovf.
+!
+! INPUTS
+! - %l1 = pc at trap time.
+! - %l2 = npc at trap time.
+! - %l7 = return address.
+!
+! INTERNAL DESCRIPTION
+!
+! RETURNS
+! - None.
+!
+
+ .align 4
+
+_chk4ovflo:
+ mov %psr, %l0 ! get the psr
+ and %l0, 0x1F, %l3 ! get the cwp
+ mov 1, %l4 ! compare cwp with the wim
+ sll %l4, %l3, %l3 ! compare
+ mov %wim, %l4 ! read the wim
+ btst %l4, %l3
+ bz _retsave ! not invalid window, just return
+ nop
+ ! in line version of _win_ovf
+ or %l0, 0xf20, %l3 ! enable traps, disable interrupts.
+ mov %l3, %psr
+ mov %g1, %l0 ! Save %g1.
+ srl %l4, 1, %g1 ! Next WIM = %g1 = rol(WIM, 1, NWINDOW)
+ sll %l4, 8-1, %l3
+ bset %l3, %g1
+ save %g0, %g0, %g0 ! Get into window to be saved.
+ mov %g1, %wim ! Install new wim.
+ nop ! must delay three instructions
+ nop ! before using these registers, so
+ nop ! put nops in just to be safe
+
+ std %l0, [%sp + 0 * 4] ! save all local 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 %l0, %g1 ! Restore %g1.
+
+_retsave:
+ ! It is safe now to allocate a stack frame for this window
+ ! because all overflow handling will have been accomplished
+ ! in the event we trapped into the invalid window.
+ ! ie. all of this window's %o regs (next window's %i regs)
+ ! will have been safely stored to the stack before we overwrite %sp.
+
+ jmpl %l7+8, %g0 ! Window is valid, just return
+ sub %fp, (16+1+6+1)*4, %sp ! Make room for input & locals
+ ! + hidden arg + arg spill
+ ! + doubleword alignment
+
+! Read the TBR.
+
+ .globl _rdtbr
+_rdtbr:
+ retl
+ mov %tbr, %o0
+
+! 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.
+
+_trap_low:
+ set _registers, %l0
+
+ std %g0, [%l0 + 0 * 4] ! registers[Gx]
+ std %g2, [%l0 + 2 * 4]
+ std %g4, [%l0 + 4 * 4]
+ std %g6, [%l0 + 6 * 4]
+
+ std %i0, [%l0 + 8 * 4] ! registers[Ox]
+ std %i2, [%l0 + 10 * 4]
+ std %i4, [%l0 + 12 * 4]
+ std %i6, [%l0 + 14 * 4]
+ ! F0->F31 not implemented
+ mov %y, %l4
+ mov %psr, %l5
+ mov %wim, %l6
+ mov %tbr, %l7
+ std %l4, [%l0 + 64 * 4] ! Y & PSR
+ std %l6, [%l0 + 66 * 4] ! WIM & TBR
+ st %l1, [%l0 + 68 * 4] ! PC
+ st %l2, [%l0 + 69 * 4] ! NPC
+
+ ! CPSR and FPSR not impl
+
+ sethi %hi(_chk4ovflo), %l7 ! Must call this routine via %l7
+ jmpl %l7+%lo(_chk4ovflo), %l7 ! because o regs may not be available yet
+ nop
+ mov %psr, %o1
+ bset 0xf20, %o1
+ mov %o1, %psr ! Turn on traps, disable interrupts
+
+ call _handle_exception
+ nop
+ mov %o0, %l7 ! Save return value
+
+! Reload all of the registers that aren't on the stack
+
+ set _registers, %l0 ! Need to use reg immune from save/rest
+
+ ld [%l0 + 1 * 4], %g1 ! registers[Gx]
+ ldd [%l0 + 2 * 4], %g2
+ ldd [%l0 + 4 * 4], %g4
+ ldd [%l0 + 6 * 4], %g6
+
+ ldd [%l0 + 8 * 4], %o0 ! registers[Ox]
+ ldd [%l0 + 10 * 4], %o2
+ ldd [%l0 + 12 * 4], %o4
+ ldd [%l0 + 14 * 4], %o6
+
+ restore ! Ensure that previous window is valid
+ save %g0, %g0, %g0 ! by causing a window_underflow trap
+
+ ld [%l0 + 64 * 4], %l3 ! registers[Y]
+ mov %l3, %y
+ ld [%l0 + 65 * 4], %l3 ! registers[PSR]
+ ld [%l0 + 68 * 4], %l1 ! registers[PC]
+ ld [%l0 + 69 * 4], %l2 ! registers[NPC]
+
+ tst %l7 ! Did handle_exception tell
+ bg retskip ! us to skip the next inst?
+ nop
+
+ mov %l3, %psr ! Make sure that traps are disabled
+ ! for rett
+ jmpl %l1, %g0 ! Restore old PC
+ rett %l2 ! Restore old nPC
+
+ mov %l3, %psr ! Make sure that traps are disabled
+ ! for rett
+retskip: ! Come here to skip the next instruction
+ jmpl %l2, %g0 ! Old nPC
+ rett %l2+4 ! Old nPC+4
+");
+
+/* 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 $<data>#<checksum> */
+
+static void
+getpacket(buffer)
+ char *buffer;
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ unsigned char ch;
+
+ do
+ {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = getDebugChar()) != '$') ;
+
+ checksum = 0;
+ xmitcsum = -1;
+
+ count = 0;
+
+ /* now, read until a # or end of buffer is found */
+ while (count < BUFMAX)
+ {
+ ch = getDebugChar();
+ if (ch == '#')
+ break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+
+ if (count >= BUFMAX)
+ continue;
+
+ buffer[count] = 0;
+
+ if (ch == '#')
+ {
+ xmitcsum = hex(getDebugChar()) << 4;
+ xmitcsum |= hex(getDebugChar());
+#ifdef DEBUG
+ if (remote_debug && checksum != xmitcsum)
+ {
+ fprintf(stderr, "bad checksum. My count = 0x%x, sent=0x%x. buf=%s\n",
+ checksum,xmitcsum,buffer);
+ }
+#endif
+#if 1
+ /* 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])
+ {
+ if (! putDebugChar(ch))
+ return;
+ checksum += ch;
+ count += 1;
+ }
+
+ putDebugChar('#');
+ putDebugChar(hexchars[checksum >> 4]);
+ putDebugChar(hexchars[checksum & 0xf]);
+
+ }
+ while (getDebugChar() != '+');
+}
+
+static unsigned char remcomInBuffer[BUFMAX];
+static unsigned char remcomOutBuffer[BUFMAX];
+static short error;
+
+static void
+debug_error(format, parm)
+ char *format;
+ char *parm;
+{
+#ifdef DEBUG
+ if (remote_debug)
+ fprintf(stderr,format,parm);
+#endif
+}
+
+/* Address of a routine to RTE to if we get a memory fault. */
+static void (*mem_fault_routine)() = NULL;
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an
+ error. */
+
+static volatile int mem_err = 0;
+
+/* 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;
+{
+ return *addr;
+}
+
+static void
+set_char (addr, val)
+ char *addr;
+ int val;
+{
+ *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), 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 = get_char(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++);
+ set_char(mem++, ch);
+ if (mem_err)
+ return 0;
+ }
+
+ set_mem_fault_trap(0);
+
+ return mem;
+}
+
+/* this function takes the SPARC trap type code and attempts to
+ translate this number into a unix compatible signal value */
+
+static int
+computeSignal(tt)
+ int tt;
+{
+ int sigval;
+
+ switch (tt)
+ {
+ case 1:
+ sigval = SIGSEGV; break; /* instruction access error */
+ case 2:
+ sigval = SIGILL; break; /* privileged instruction */
+ case 3:
+ sigval = SIGILL; break; /* illegal instruction */
+ case 4:
+ sigval = SIGEMT; break; /* fp disabled */
+ case 36:
+ sigval = SIGEMT; break; /* cp disabled */
+ case 7:
+ sigval = SIGBUS; break; /* mem address not aligned */
+ case 9:
+ sigval = SIGSEGV; break; /* data access exception */
+ case 10:
+ sigval = SIGEMT; break; /* tag overflow */
+ case 128+1: /* ta 1 - normal breakpoint instruction */
+ case 255: /* breakpoint hardware unique to SPARClite */
+ sigval = SIGTRAP; break; /* breakpoint trap */
+ default:
+ sigval = SIGHUP; /* "software generated"*/
+ }
+ return (sigval);
+}
+
+/*
+ * 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)
+ {
+ *intValue = (*intValue <<4) | hexValue;
+ numChars ++;
+ }
+ else
+ break;
+
+ (*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.
+ */
+
+static int
+handle_exception ()
+{
+ int tt; /* Trap type */
+ int sigval;
+ int addr;
+ int length;
+ char *ptr;
+ int newPC;
+ unsigned char *sp;
+ unsigned char *com;
+
+/* First, we must force all of the windows to be spilled out */
+
+ asm(" save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ save %g0, -64, %g0
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+");
+
+#if 0
+ writez(1, "Got to handle_exception()\r\n ");
+
+ writez(1, "psr = 0x");
+ numout(registers[PSR], 16);
+ writez(1, " tbr = 0x");
+ numout(registers[TBR], 16);
+ writez(1, " oldpc = 0x");
+ numout(registers[PC], 16);
+ writez(1, " oldnpc = 0x");
+ numout(registers[NPC], 16);
+ writez(1, "\r\n");
+#endif
+
+ sp = (unsigned char *)registers[SP];
+
+ tt = (registers[TBR] >> 4) & 0xff;
+
+#ifdef DEBUG
+ if (remote_debug)
+ printf("tbr=0x%x, tt=%d, psr=0x%x, pc=0x%x, npc=0x%x\n",
+ registers[TBR], (registers[TBR] >> 4) & 0xff, registers[PSR], registers[PC], registers[NPC]);
+#endif
+
+ /* reply to host that an exception has occurred */
+ sigval = computeSignal(tt);
+ com = remcomOutBuffer;
+
+ *com++ = 'T';
+ *com++ = hexchars[sigval >> 4];
+ *com++ = hexchars[sigval & 0xf];
+
+ *com++ = hexchars[PC >> 4];
+ *com++ = hexchars[PC & 0xf];
+ com = mem2hex((char *)®isters[PC], com, 4, 0);
+
+ *com++ = hexchars[FP >> 4];
+ *com++ = hexchars[FP & 0xf];
+ com = mem2hex(sp + (8 + 6) * 4, com, 4, 0); /* FP */
+
+ *com++ = hexchars[SP >> 4];
+ *com++ = hexchars[SP & 0xf];
+ com = mem2hex((char *)®isters[SP], com, 4, 0);
+
+ *com++ = hexchars[NPC >> 4];
+ *com++ = hexchars[NPC & 0xf];
+ com = mem2hex((char *)®isters[NPC], com, 4, 0);
+
+ *com++ = 0;
+
+ putpacket(remcomOutBuffer);
+
+ while (1)
+ {
+ error = 0;
+ 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':
+ remote_debug = !remote_debug; /* toggle debug flag */
+ break;
+
+ case 'g': /* return the value of the CPU registers */
+ {
+ com = remcomOutBuffer;
+ com = mem2hex((char *)registers, com, 16 * 4, 0); /* G & O regs */
+ com = mem2hex(sp + 0 * 4, com, 8 * 4, 0); /* L regs */
+ com = mem2hex(sp + 8 * 4, com, 8 * 4, 0); /* I regs */
+ memset(com, '0', 32 * 8); /* Floating point */
+ mem2hex((char *)®isters[Y],
+ com + 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 */
+ {
+ com = &remcomInBuffer[1];
+ hex2mem(com, (char *)registers, 16 * 4, 0); /* G & O regs */
+ hex2mem(com + 16 * 4 * 2, sp + 0 * 4, 8 * 4, 0); /* L regs */
+ hex2mem(com + 24 * 4 * 2, sp + 8 * 4, 8 * 4, 0); /* I regs */
+ hex2mem(com + 64 * 4 * 2, (char *)®isters[Y],
+ 8 * 4, 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ strcpy(remcomOutBuffer,"OK");
+ }
+ 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)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length))
+ {
+ if (mem2hex((char *)addr, remcomOutBuffer, length, 1))
+ break;
+
+ strcpy (remcomOutBuffer, "E03");
+ debug_error ("memory fault");
+ }
+ else
+ {
+ strcpy(remcomOutBuffer,"E01");
+ debug_error("malformed read memory command: %s",remcomInBuffer);
+ }
+ 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)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length)
+ && *ptr++ == ':')
+ {
+ if (hex2mem(ptr, (char *)addr, length, 1))
+ strcpy(remcomOutBuffer, "OK");
+ else
+ {
+ strcpy(remcomOutBuffer, "E03");
+ debug_error("memory fault");
+ }
+ }
+ else
+ {
+ strcpy(remcomOutBuffer, "E02");
+ debug_error("malformed write memory command: %s",remcomInBuffer);
+ }
+ break;
+
+ case 'c': /* cAA..AA Continue at address AA..AA(optional) */
+ case 's': /* sAA..AA Step one instruction from 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;
+ }
+
+ return 0;
+
+ /* kill the program */
+ case 'k' : /* do nothing */
+ break;
+ } /* switch */
+
+ /* reply to the request */
+ putpacket(remcomOutBuffer);
+ }
+}
+
+/* Each entry in the trap vector occupies four words. */
+
+struct trap_entry
+{
+ unsigned long ti[4];
+};
+
+#define NUMTRAPS 256
+
+/* static struct trap_entry oldvec[NUMTRAPS];*/
+
+extern struct trap_entry fltr_proto;
+extern struct trap_entry fltr_set_mem_err;
+asm ("
+ .data
+ .globl _fltr_proto
+ .align 4
+_fltr_proto: ! First level trap routine prototype
+ sethi %hi(_trap_low), %l0
+ jmpl %lo(_trap_low)+%l0, %g0
+ nop
+ nop
+
+! 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.
+
+_fltr_set_mem_err:
+ sethi %hi(_mem_err), %l0
+ st %l1, [%l0 + %lo(_mem_err)]
+ jmpl %l2, %g0
+ rett %l2+4
+
+ .text
+");
+
+/* this function is used to set up exception handlers for tracing and
+ breakpoints */
+
+void
+set_debug_traps()
+{
+ int exception;
+ struct trap_entry *tb; /* Trap vector base address */
+
+ writez(1, "Got to set_debug_traps\r\n");
+
+ tb = (struct trap_entry *)(rdtbr() & ~0xfff);
+
+ writez(1, "tb = 0x");
+ numout(tb, 16);
+ writez(1, " trap ins = 0x");
+ numout(fltr_proto, 16);
+ writez(1, "\r\n");
+
+ tb[1] = fltr_proto; /* instruction access exception */
+ tb[2] = fltr_proto; /* privileged instruction */
+ tb[3] = fltr_proto; /* illegal instruction */
+ tb[4] = fltr_proto; /* fp disabled */
+ tb[36] = fltr_proto; /* cp disabled */
+ tb[7] = fltr_proto; /* mem address not aligned */
+ tb[9] = fltr_proto; /* data access exception */
+ tb[10] = fltr_proto; /* tag overflow */
+ tb[128+1] = fltr_proto; /* breakpoint instruction (ta 1) */
+ tb[255] = fltr_proto; /* hardware breakpoint trap */
+
+ /* In case GDB is started before us, ack any packets (presumably
+ "$?#xx") sitting there. */
+
+ putDebugChar ('+');
+
+ initialized = 1;
+}
+
+static void
+set_mem_fault_trap(enable)
+ int enable;
+{
+ struct trap_entry *tb; /* Trap vector base address */
+
+ mem_err = 0;
+
+ tb = (struct trap_entry *)(rdtbr() & ~0xfff);
+
+ if (enable)
+ tb[9] = fltr_set_mem_err;
+ else
+ tb[9] = fltr_proto;
+}
+
+/* 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()
+{
+ writez(1, "About to do a breakpoint\r\n\n");
+ if (initialized)
+ BREAKPOINT();
+}
projects / binutils-gdb.git / commitdiff