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diff --git a/arch/sparc/kernel/sparc-stub.c b/arch/sparc/kernel/sparc-stub.c
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+/* $Id: sparc-stub.c,v 1.28 2001/10/30 04:54:21 davem Exp $
+ * sparc-stub.c: KGDB support for the Linux kernel.
+ *
+ * Modifications to run under Linux
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ *
+ * This file originally came from the gdb sources, and the
+ * copyright notices have been retained below.
+ */
+
+/****************************************************************************
+
+ 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 its 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 <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+
+#include <asm/system.h>
+#include <asm/signal.h>
+#include <asm/oplib.h>
+#include <asm/head.h>
+#include <asm/traps.h>
+#include <asm/vac-ops.h>
+#include <asm/kgdb.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+
+/*
+ *
+ * external low-level support routines
+ */
+
+extern void putDebugChar(char); /* write a single character */
+extern char getDebugChar(void); /* 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 means we've been initialized */
+
+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 };
+
+
+extern void trap_low(void); /* In arch/sparc/kernel/entry.S */
+
+unsigned long get_sun4cpte(unsigned long addr)
+{
+ unsigned long entry;
+
+ __asm__ __volatile__("\n\tlda [%1] %2, %0\n\t" :
+ "=r" (entry) :
+ "r" (addr), "i" (ASI_PTE));
+ return entry;
+}
+
+unsigned long get_sun4csegmap(unsigned long addr)
+{
+ unsigned long entry;
+
+ __asm__ __volatile__("\n\tlduba [%1] %2, %0\n\t" :
+ "=r" (entry) :
+ "r" (addr), "i" (ASI_SEGMAP));
+ return entry;
+}
+
+#if 0
+/* Have to sort this out. This cannot be done after initialization. */
+static void flush_cache_all_nop(void) {}
+#endif
+
+/* Place where we save old trap entries for restoration */
+struct tt_entry kgdb_savettable[256];
+typedef void (*trapfunc_t)(void);
+
+/* Helper routine for manipulation of kgdb_savettable */
+static inline void copy_ttentry(struct tt_entry *src, struct tt_entry *dest)
+{
+ dest->inst_one = src->inst_one;
+ dest->inst_two = src->inst_two;
+ dest->inst_three = src->inst_three;
+ dest->inst_four = src->inst_four;
+}
+
+/* Initialize the kgdb_savettable so that debugging can commence */
+static void eh_init(void)
+{
+ int i;
+
+ for(i=0; i < 256; i++)
+ copy_ttentry(&sparc_ttable[i], &kgdb_savettable[i]);
+}
+
+/* Install an exception handler for kgdb */
+static void exceptionHandler(int tnum, trapfunc_t trap_entry)
+{
+ unsigned long te_addr = (unsigned long) trap_entry;
+
+ /* Make new vector */
+ sparc_ttable[tnum].inst_one =
+ SPARC_BRANCH((unsigned long) te_addr,
+ (unsigned long) &sparc_ttable[tnum].inst_one);
+ sparc_ttable[tnum].inst_two = SPARC_RD_PSR_L0;
+ sparc_ttable[tnum].inst_three = SPARC_NOP;
+ sparc_ttable[tnum].inst_four = SPARC_NOP;
+}
+
+/* Convert ch from a hex digit to an int */
+static int
+hex(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 $<data>#<checksum> */
+static void
+getpacket(char *buffer)
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ unsigned char ch;
+
+ do {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = (getDebugChar() & 0x7f)) != '$') ;
+
+ 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 (checksum != xmitcsum)
+ putDebugChar('-'); /* failed checksum */
+ else {
+ putDebugChar('+'); /* successful transfer */
+ /* if a sequence char is present, reply the 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(unsigned char *buffer)
+{
+ unsigned char checksum;
+ int count;
+ unsigned char ch, recv;
+
+ /* $<packet info>#<checksum>. */
+ do {
+ putDebugChar('$');
+ checksum = 0;
+ count = 0;
+
+ while ((ch = buffer[count])) {
+ putDebugChar(ch);
+ checksum += ch;
+ count += 1;
+ }
+
+ putDebugChar('#');
+ putDebugChar(hexchars[checksum >> 4]);
+ putDebugChar(hexchars[checksum & 0xf]);
+ recv = getDebugChar();
+ } while ((recv & 0x7f) != '+');
+}
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/* 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.
+ */
+
+static unsigned char *
+mem2hex(char *mem, char *buf, int count)
+{
+ unsigned char ch;
+
+ while (count-- > 0) {
+ /* This assembler code is basically: ch = *mem++;
+ * except that we use the SPARC/Linux exception table
+ * mechanism (see how "fixup" works in kernel_mna_trap_fault)
+ * to arrange for a "return 0" upon a memory fault
+ */
+ __asm__(
+ "\n1:\n\t"
+ "ldub [%0], %1\n\t"
+ "inc %0\n\t"
+ ".section .fixup,#alloc,#execinstr\n\t"
+ ".align 4\n"
+ "2:\n\t"
+ "retl\n\t"
+ " mov 0, %%o0\n\t"
+ ".section __ex_table, #alloc\n\t"
+ ".align 4\n\t"
+ ".word 1b, 2b\n\t"
+ ".text\n"
+ : "=r" (mem), "=r" (ch) : "0" (mem));
+ *buf++ = hexchars[ch >> 4];
+ *buf++ = hexchars[ch & 0xf];
+ }
+
+ *buf = 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(char *buf, char *mem, int count)
+{
+ int i;
+ unsigned char ch;
+
+ for (i=0; i<count; i++) {
+
+ ch = hex(*buf++) << 4;
+ ch |= hex(*buf++);
+ /* Assembler code is *mem++ = ch; with return 0 on fault */
+ __asm__(
+ "\n1:\n\t"
+ "stb %1, [%0]\n\t"
+ "inc %0\n\t"
+ ".section .fixup,#alloc,#execinstr\n\t"
+ ".align 4\n"
+ "2:\n\t"
+ "retl\n\t"
+ " mov 0, %%o0\n\t"
+ ".section __ex_table, #alloc\n\t"
+ ".align 4\n\t"
+ ".word 1b, 2b\n\t"
+ ".text\n"
+ : "=r" (mem) : "r" (ch) , "0" (mem));
+ }
+ 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 SPARC */
+ unsigned char signo; /* Signal that we map this trap into */
+} hard_trap_info[] = {
+ {SP_TRAP_SBPT, SIGTRAP}, /* ta 1 - Linux/KGDB software breakpoint */
+ {0, 0} /* Must be last */
+};
+
+/* Set up exception handlers for tracing and breakpoints */
+
+void
+set_debug_traps(void)
+{
+ struct hard_trap_info *ht;
+ unsigned long flags;
+
+ local_irq_save(flags);
+#if 0
+/* Have to sort this out. This cannot be done after initialization. */
+ BTFIXUPSET_CALL(flush_cache_all, flush_cache_all_nop, BTFIXUPCALL_NOP);
+#endif
+
+ /* Initialize our copy of the Linux Sparc trap table */
+ eh_init();
+
+ for (ht = hard_trap_info; ht->tt && ht->signo; ht++) {
+ /* Only if it doesn't destroy our fault handlers */
+ if((ht->tt != SP_TRAP_TFLT) &&
+ (ht->tt != SP_TRAP_DFLT))
+ exceptionHandler(ht->tt, trap_low);
+ }
+
+ /* In case GDB is started before us, ack any packets (presumably
+ * "$?#xx") sitting there.
+ *
+ * I've found this code causes more problems than it solves,
+ * so that's why it's commented out. GDB seems to work fine
+ * now starting either before or after the kernel -bwb
+ */
+#if 0
+ while((c = getDebugChar()) != '$');
+ while((c = getDebugChar()) != '#');
+ c = getDebugChar(); /* eat first csum byte */
+ c = getDebugChar(); /* eat second csum byte */
+ putDebugChar('+'); /* ack it */
+#endif
+
+ initialized = 1; /* connect! */
+ local_irq_restore(flags);
+}
+
+/* Convert the SPARC hardware trap type code to a unix signal number. */
+
+static int
+computeSignal(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 processing for interfacing to gdb. It
+ * returns 1 if you should skip the instruction at the trap address, 0
+ * otherwise.
+ */
+
+extern void breakinst(void);
+
+void
+handle_exception (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\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "save %sp, -64, %sp\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t"
+ "restore\n\t");
+
+ lock_kernel();
+ if (registers[PC] == (unsigned long)breakinst) {
+ /* Skip over breakpoint trap insn */
+ 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 *)&registers[PC], ptr, 4);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[FP >> 4];
+ *ptr++ = hexchars[FP & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *) (sp + 8 + 6), ptr, 4); /* FP */
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[SP >> 4];
+ *ptr++ = hexchars[SP & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&sp, ptr, 4);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[NPC >> 4];
+ *ptr++ = hexchars[NPC & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&registers[NPC], ptr, 4);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[O7 >> 4];
+ *ptr++ = hexchars[O7 & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&registers[O7], ptr, 4);
+ *ptr++ = ';';
+
+ *ptr++ = 0;
+
+ putpacket(remcomOutBuffer);
+
+ /* XXX We may want to add some features dealing with poking the
+ * XXX page tables, the real ones on the srmmu, and what is currently
+ * XXX loaded in the sun4/sun4c tlb at this point in time. But this
+ * XXX also required hacking to the gdb sources directly...
+ */
+
+ 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;
+ /* G & O regs */
+ ptr = mem2hex((char *)registers, ptr, 16 * 4);
+ /* L & I regs */
+ ptr = mem2hex((char *) (sp + 0), ptr, 16 * 4);
+ /* Floating point */
+ memset(ptr, '0', 32 * 8);
+ /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ mem2hex((char *)&registers[Y], (ptr + 32 * 4 * 2), (8 * 4));
+ }
+ break;
+
+ case 'G': /* set the value of the CPU registers - return OK */
+ {
+ unsigned long *newsp, psr;
+
+ psr = registers[PSR];
+
+ ptr = &remcomInBuffer[1];
+ /* G & O regs */
+ hex2mem(ptr, (char *)registers, 16 * 4);
+ /* L & I regs */
+ hex2mem(ptr + 16 * 4 * 2, (char *) (sp + 0), 16 * 4);
+ /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ hex2mem(ptr + 64 * 4 * 2, (char *)&registers[Y], 8 * 4);
+
+ /* 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))
+ 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)) {
+ 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_cache_all();
+ unlock_kernel();
+ return;
+
+ /* kill the program */
+ case 'k' : /* do nothing */
+ break;
+ case 'r': /* Reset */
+ asm ("call 0\n\t"
+ "nop\n\t");
+ break;
+ } /* switch */
+
+ /* reply to the request */
+ putpacket(remcomOutBuffer);
+ } /* while(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. */
+
+void
+breakpoint(void)
+{
+ if (!initialized)
+ return;
+
+ /* Again, watch those c-prefixes for ELF kernels */
+#if defined(__svr4__) || defined(__ELF__)
+ asm(".globl breakinst\n"
+ "breakinst:\n\t"
+ "ta 1\n");
+#else
+ asm(".globl _breakinst\n"
+ "_breakinst:\n\t"
+ "ta 1\n");
+#endif
+}
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