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authorDavid S. Miller <davem@davemloft.net>2008-04-29 11:38:50 +0200
committerDavid S. Miller <davem@davemloft.net>2008-04-29 11:38:50 +0200
commite2fdd7fd99dd68b77caaf2a2272b75b5da890de7 (patch)
treed2b6d3a9b50e4d2ced793430d2b1414f790666a3 /arch/sparc/kernel/sparc-stub.c
parentkgdbts: Sparc needs sstep emulation. (diff)
downloadlinux-e2fdd7fd99dd68b77caaf2a2272b75b5da890de7.tar.xz
linux-e2fdd7fd99dd68b77caaf2a2272b75b5da890de7.zip
sparc: Add kgdb support.
Current limitations: 1) On SMP single stepping has some fundamental issues, shared with other sw single-step architectures such as mips and arm. 2) On 32-bit sparc we don't support SMP kgdb yet. That requires some reworking of the IPI mechanisms and infrastructure on that platform. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/sparc-stub.c')
-rw-r--r--arch/sparc/kernel/sparc-stub.c724
1 files changed, 0 insertions, 724 deletions
diff --git a/arch/sparc/kernel/sparc-stub.c b/arch/sparc/kernel/sparc-stub.c
deleted file mode 100644
index e84f815e6903..000000000000
--- a/arch/sparc/kernel/sparc-stub.c
+++ /dev/null
@@ -1,724 +0,0 @@
-/* $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
-}