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linux/arch/mn10300/kernel/gdb-stub.c

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// SPDX-License-Identifier: GPL-2.0
/* MN10300 GDB stub
*
* Originally written by Glenn Engel, Lake Stevens Instrument Division
*
* Contributed by HP Systems
*
* Modified for SPARC by Stu Grossman, Cygnus Support.
*
* Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
* Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
*
* Copyright (C) 1995 Andreas Busse
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Modified for Linux/mn10300 by David Howells <dhowells@redhat.com>
*/
/*
* 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 BREAK instruction.
*
*
* 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
*
*
* ==============
* MORE EXAMPLES:
* ==============
*
* For reference -- the following are the steps that one
* company took (RidgeRun Inc) to get remote gdb debugging
* going. In this scenario the host machine was a PC and the
* target platform was a Galileo EVB64120A MIPS evaluation
* board.
*
* Step 1:
* First download gdb-5.0.tar.gz from the internet.
* and then build/install the package.
*
* Example:
* $ tar zxf gdb-5.0.tar.gz
* $ cd gdb-5.0
* $ ./configure --target=am33_2.0-linux-gnu
* $ make
* $ install
* am33_2.0-linux-gnu-gdb
*
* Step 2:
* Configure linux for remote debugging and build it.
*
* Example:
* $ cd ~/linux
* $ make menuconfig <go to "Kernel Hacking" and turn on remote debugging>
* $ make dep; make vmlinux
*
* Step 3:
* Download the kernel to the remote target and start
* the kernel running. It will promptly halt and wait
* for the host gdb session to connect. It does this
* since the "Kernel Hacking" option has defined
* CONFIG_REMOTE_DEBUG which in turn enables your calls
* to:
* set_debug_traps();
* breakpoint();
*
* Step 4:
* Start the gdb session on the host.
*
* Example:
* $ am33_2.0-linux-gnu-gdb vmlinux
* (gdb) set remotebaud 115200
* (gdb) target remote /dev/ttyS1
* ...at this point you are connected to
* the remote target and can use gdb
* in the normal fasion. Setting
* breakpoints, single stepping,
* printing variables, etc.
*
*/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/bug.h>
#include <asm/pgtable.h>
#include <asm/gdb-stub.h>
#include <asm/exceptions.h>
#include <asm/debugger.h>
#include <asm/serial-regs.h>
#include <asm/busctl-regs.h>
#include <unit/leds.h>
#include <unit/serial.h>
/* define to use F7F7 rather than FF which is subverted by JTAG debugger */
#undef GDBSTUB_USE_F7F7_AS_BREAKPOINT
/*
* BUFMAX defines the maximum number of characters in inbound/outbound buffers
* at least NUMREGBYTES*2 are needed for register packets
*/
#define BUFMAX 2048
static const char gdbstub_banner[] =
"Linux/MN10300 GDB Stub (c) RedHat 2007\n";
u8 gdbstub_rx_buffer[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
u32 gdbstub_rx_inp;
u32 gdbstub_rx_outp;
u8 gdbstub_busy;
u8 gdbstub_rx_overflow;
u8 gdbstub_rx_unget;
static u8 gdbstub_flush_caches;
static char input_buffer[BUFMAX];
static char output_buffer[BUFMAX];
static char trans_buffer[BUFMAX];
struct gdbstub_bkpt {
u8 *addr; /* address of breakpoint */
u8 len; /* size of breakpoint */
u8 origbytes[7]; /* original bytes */
};
static struct gdbstub_bkpt gdbstub_bkpts[256];
/*
* local prototypes
*/
static void getpacket(char *buffer);
static int putpacket(char *buffer);
static int computeSignal(enum exception_code excep);
static int hex(unsigned char ch);
static int hexToInt(char **ptr, int *intValue);
static unsigned char *mem2hex(const void *mem, char *buf, int count,
int may_fault);
static const char *hex2mem(const char *buf, void *_mem, int count,
int may_fault);
/*
* 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;
}
#ifdef CONFIG_GDBSTUB_DEBUGGING
void debug_to_serial(const char *p, int n)
{
__debug_to_serial(p, n);
/* gdbstub_console_write(NULL, p, n); */
}
void gdbstub_printk(const char *fmt, ...)
{
va_list args;
int len;
/* Emit the output into the temporary buffer */
va_start(args, fmt);
len = vsnprintf(trans_buffer, sizeof(trans_buffer), fmt, args);
va_end(args);
debug_to_serial(trans_buffer, len);
}
#endif
static inline char *gdbstub_strcpy(char *dst, const char *src)
{
int loop = 0;
while ((dst[loop] = src[loop]))
loop++;
return dst;
}
/*
* scan for the sequence $<data>#<checksum>
*/
static void getpacket(char *buffer)
{
unsigned char checksum;
unsigned char xmitcsum;
unsigned char ch;
int count, i, ret, error;
for (;;) {
/*
* wait around for the start character,
* ignore all other characters
*/
do {
gdbstub_io_rx_char(&ch, 0);
} while (ch != '$');
checksum = 0;
xmitcsum = -1;
count = 0;
error = 0;
/*
* now, read until a # or end of buffer is found
*/
while (count < BUFMAX) {
ret = gdbstub_io_rx_char(&ch, 0);
if (ret < 0)
error = ret;
if (ch == '#')
break;
checksum += ch;
buffer[count] = ch;
count++;
}
if (error == -EIO) {
gdbstub_proto("### GDB Rx Error - Skipping packet"
" ###\n");
gdbstub_proto("### GDB Tx NAK\n");
gdbstub_io_tx_char('-');
continue;
}
if (count >= BUFMAX || error)
continue;
buffer[count] = 0;
/* read the checksum */
ret = gdbstub_io_rx_char(&ch, 0);
if (ret < 0)
error = ret;
xmitcsum = hex(ch) << 4;
ret = gdbstub_io_rx_char(&ch, 0);
if (ret < 0)
error = ret;
xmitcsum |= hex(ch);
if (error) {
if (error == -EIO)
gdbstub_io("### GDB Rx Error -"
" Skipping packet\n");
gdbstub_io("### GDB Tx NAK\n");
gdbstub_io_tx_char('-');
continue;
}
/* check the checksum */
if (checksum != xmitcsum) {
gdbstub_io("### GDB Tx NAK\n");
gdbstub_io_tx_char('-'); /* failed checksum */
continue;
}
gdbstub_proto("### GDB Rx '$%s#%02x' ###\n", buffer, checksum);
gdbstub_io("### GDB Tx ACK\n");
gdbstub_io_tx_char('+'); /* successful transfer */
/*
* if a sequence char is present,
* reply the sequence ID
*/
if (buffer[2] == ':') {
gdbstub_io_tx_char(buffer[0]);
gdbstub_io_tx_char(buffer[1]);
/*
* remove sequence chars from buffer
*/
count = 0;
while (buffer[count])
count++;
for (i = 3; i <= count; i++)
buffer[i - 3] = buffer[i];
}
break;
}
}
/*
* send the packet in buffer.
* - return 0 if successfully ACK'd
* - return 1 if abandoned due to new incoming packet
*/
static int putpacket(char *buffer)
{
unsigned char checksum;
unsigned char ch;
int count;
/*
* $<packet info>#<checksum>.
*/
gdbstub_proto("### GDB Tx $'%s'#?? ###\n", buffer);
do {
gdbstub_io_tx_char('$');
checksum = 0;
count = 0;
while ((ch = buffer[count]) != 0) {
gdbstub_io_tx_char(ch);
checksum += ch;
count += 1;
}
gdbstub_io_tx_char('#');
gdbstub_io_tx_char(hex_asc_hi(checksum));
gdbstub_io_tx_char(hex_asc_lo(checksum));
} while (gdbstub_io_rx_char(&ch, 0),
ch == '-' && (gdbstub_io("### GDB Rx NAK\n"), 0),
ch != '-' && ch != '+' &&
(gdbstub_io("### GDB Rx ??? %02x\n", ch), 0),
ch != '+' && ch != '$');
if (ch == '+') {
gdbstub_io("### GDB Rx ACK\n");
return 0;
}
gdbstub_io("### GDB Tx Abandoned\n");
gdbstub_rx_unget = ch;
return 1;
}
/*
* 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);
}
#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
/*
* We single-step by setting breakpoints. When an exception
* is handled, we need to restore the instructions hoisted
* when the breakpoints were set.
*
* This is where we save the original instructions.
*/
static struct gdb_bp_save {
u8 *addr;
u8 opcode[2];
} step_bp[2];
static const unsigned char gdbstub_insn_sizes[256] =
{
/* 1 2 3 4 5 6 7 8 9 a b c d e f */
1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
};
static int __gdbstub_mark_bp(u8 *addr, int ix)
{
/* vmalloc area */
if (((u8 *) VMALLOC_START <= addr) && (addr < (u8 *) VMALLOC_END))
goto okay;
/* SRAM, SDRAM */
if (((u8 *) 0x80000000UL <= addr) && (addr < (u8 *) 0xa0000000UL))
goto okay;
return 0;
okay:
if (gdbstub_read_byte(addr + 0, &step_bp[ix].opcode[0]) < 0 ||
gdbstub_read_byte(addr + 1, &step_bp[ix].opcode[1]) < 0)
return 0;
step_bp[ix].addr = addr;
return 1;
}
static inline void __gdbstub_restore_bp(void)
{
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
if (step_bp[0].addr) {
gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
gdbstub_write_byte(step_bp[0].opcode[1], step_bp[0].addr + 1);
}
if (step_bp[1].addr) {
gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
gdbstub_write_byte(step_bp[1].opcode[1], step_bp[1].addr + 1);
}
#else
if (step_bp[0].addr)
gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
if (step_bp[1].addr)
gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
#endif
gdbstub_flush_caches = 1;
step_bp[0].addr = NULL;
step_bp[0].opcode[0] = 0;
step_bp[0].opcode[1] = 0;
step_bp[1].addr = NULL;
step_bp[1].opcode[0] = 0;
step_bp[1].opcode[1] = 0;
}
/*
* emulate single stepping by means of breakpoint instructions
*/
static int gdbstub_single_step(struct pt_regs *regs)
{
unsigned size;
uint32_t x;
uint8_t cur, *pc, *sp;
step_bp[0].addr = NULL;
step_bp[0].opcode[0] = 0;
step_bp[0].opcode[1] = 0;
step_bp[1].addr = NULL;
step_bp[1].opcode[0] = 0;
step_bp[1].opcode[1] = 0;
x = 0;
pc = (u8 *) regs->pc;
sp = (u8 *) (regs + 1);
if (gdbstub_read_byte(pc, &cur) < 0)
return -EFAULT;
gdbstub_bkpt("Single Step from %p { %02x }\n", pc, cur);
gdbstub_flush_caches = 1;
size = gdbstub_insn_sizes[cur];
if (size > 0) {
if (!__gdbstub_mark_bp(pc + size, 0))
goto fault;
} else {
switch (cur) {
/* Bxx (d8,PC) */
case 0xc0 ... 0xca:
if (gdbstub_read_byte(pc + 1, (u8 *) &x) < 0)
goto fault;
if (!__gdbstub_mark_bp(pc + 2, 0))
goto fault;
if ((x < 0 || x > 2) &&
!__gdbstub_mark_bp(pc + (s8) x, 1))
goto fault;
break;
/* LXX (d8,PC) */
case 0xd0 ... 0xda:
if (!__gdbstub_mark_bp(pc + 1, 0))
goto fault;
if (regs->pc != regs->lar &&
!__gdbstub_mark_bp((u8 *) regs->lar, 1))
goto fault;
break;
/* SETLB - loads the next for bytes into the LIR
* register */
case 0xdb:
if (!__gdbstub_mark_bp(pc + 1, 0))
goto fault;
break;
/* JMP (d16,PC) or CALL (d16,PC) */
case 0xcc:
case 0xcd:
if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0)
goto fault;
if (!__gdbstub_mark_bp(pc + (s16) x, 0))
goto fault;
break;
/* JMP (d32,PC) or CALL (d32,PC) */
case 0xdc:
case 0xdd:
if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0 ||
gdbstub_read_byte(pc + 3, ((u8 *) &x) + 2) < 0 ||
gdbstub_read_byte(pc + 4, ((u8 *) &x) + 3) < 0)
goto fault;
if (!__gdbstub_mark_bp(pc + (s32) x, 0))
goto fault;
break;
/* RETF */
case 0xde:
if (!__gdbstub_mark_bp((u8 *) regs->mdr, 0))
goto fault;
break;
/* RET */
case 0xdf:
if (gdbstub_read_byte(pc + 2, (u8 *) &x) < 0)
goto fault;
sp += (s8)x;
if (gdbstub_read_byte(sp + 0, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(sp + 1, ((u8 *) &x) + 1) < 0 ||
gdbstub_read_byte(sp + 2, ((u8 *) &x) + 2) < 0 ||
gdbstub_read_byte(sp + 3, ((u8 *) &x) + 3) < 0)
goto fault;
if (!__gdbstub_mark_bp((u8 *) x, 0))
goto fault;
break;
case 0xf0:
if (gdbstub_read_byte(pc + 1, &cur) < 0)
goto fault;
if (cur >= 0xf0 && cur <= 0xf7) {
/* JMP (An) / CALLS (An) */
switch (cur & 3) {
case 0: x = regs->a0; break;
case 1: x = regs->a1; break;
case 2: x = regs->a2; break;
case 3: x = regs->a3; break;
}
if (!__gdbstub_mark_bp((u8 *) x, 0))
goto fault;
} else if (cur == 0xfc) {
/* RETS */
if (gdbstub_read_byte(
sp + 0, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(
sp + 1, ((u8 *) &x) + 1) < 0 ||
gdbstub_read_byte(
sp + 2, ((u8 *) &x) + 2) < 0 ||
gdbstub_read_byte(
sp + 3, ((u8 *) &x) + 3) < 0)
goto fault;
if (!__gdbstub_mark_bp((u8 *) x, 0))
goto fault;
} else if (cur == 0xfd) {
/* RTI */
if (gdbstub_read_byte(
sp + 4, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(
sp + 5, ((u8 *) &x) + 1) < 0 ||
gdbstub_read_byte(
sp + 6, ((u8 *) &x) + 2) < 0 ||
gdbstub_read_byte(
sp + 7, ((u8 *) &x) + 3) < 0)
goto fault;
if (!__gdbstub_mark_bp((u8 *) x, 0))
goto fault;
} else {
if (!__gdbstub_mark_bp(pc + 2, 0))
goto fault;
}
break;
/* potential 3-byte conditional branches */
case 0xf8:
if (gdbstub_read_byte(pc + 1, &cur) < 0)
goto fault;
if (!__gdbstub_mark_bp(pc + 3, 0))
goto fault;
if (cur >= 0xe8 && cur <= 0xeb) {
if (gdbstub_read_byte(
pc + 2, ((u8 *) &x) + 0) < 0)
goto fault;
if ((x < 0 || x > 3) &&
!__gdbstub_mark_bp(pc + (s8) x, 1))
goto fault;
}
break;
case 0xfa:
if (gdbstub_read_byte(pc + 1, &cur) < 0)
goto fault;
if (cur == 0xff) {
/* CALLS (d16,PC) */
if (gdbstub_read_byte(
pc + 2, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(
pc + 3, ((u8 *) &x) + 1) < 0)
goto fault;
if (!__gdbstub_mark_bp(pc + (s16) x, 0))
goto fault;
} else {
if (!__gdbstub_mark_bp(pc + 4, 0))
goto fault;
}
break;
case 0xfc:
if (gdbstub_read_byte(pc + 1, &cur) < 0)
goto fault;
if (cur == 0xff) {
/* CALLS (d32,PC) */
if (gdbstub_read_byte(
pc + 2, ((u8 *) &x) + 0) < 0 ||
gdbstub_read_byte(
pc + 3, ((u8 *) &x) + 1) < 0 ||
gdbstub_read_byte(
pc + 4, ((u8 *) &x) + 2) < 0 ||
gdbstub_read_byte(
pc + 5, ((u8 *) &x) + 3) < 0)
goto fault;
if (!__gdbstub_mark_bp(
pc + (s32) x, 0))
goto fault;
} else {
if (!__gdbstub_mark_bp(
pc + 6, 0))
goto fault;
}
break;
}
}
gdbstub_bkpt("Step: %02x at %p; %02x at %p\n",
step_bp[0].opcode[0], step_bp[0].addr,
step_bp[1].opcode[0], step_bp[1].addr);
if (step_bp[0].addr) {
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
if (gdbstub_write_byte(0xF7, step_bp[0].addr + 0) < 0 ||
gdbstub_write_byte(0xF7, step_bp[0].addr + 1) < 0)
goto fault;
#else
if (gdbstub_write_byte(0xFF, step_bp[0].addr + 0) < 0)
goto fault;
#endif
}
if (step_bp[1].addr) {
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
if (gdbstub_write_byte(0xF7, step_bp[1].addr + 0) < 0 ||
gdbstub_write_byte(0xF7, step_bp[1].addr + 1) < 0)
goto fault;
#else
if (gdbstub_write_byte(0xFF, step_bp[1].addr + 0) < 0)
goto fault;
#endif
}
return 0;
fault:
/* uh-oh - silly address alert, try and restore things */
__gdbstub_restore_bp();
return -EFAULT;
}
#endif /* CONFIG_GDBSTUB_ALLOW_SINGLE_STEP */
#ifdef CONFIG_GDBSTUB_CONSOLE
void gdbstub_console_write(struct console *con, const char *p, unsigned n)
{
static const char gdbstub_cr[] = { 0x0d };
char outbuf[26];
int qty;
u8 busy;
busy = gdbstub_busy;
gdbstub_busy = 1;
outbuf[0] = 'O';
while (n > 0) {
qty = 1;
while (n > 0 && qty < 20) {
mem2hex(p, outbuf + qty, 2, 0);
qty += 2;
if (*p == 0x0a) {
mem2hex(gdbstub_cr, outbuf + qty, 2, 0);
qty += 2;
}
p++;
n--;
}
outbuf[qty] = 0;
putpacket(outbuf);
}
gdbstub_busy = busy;
}
static kdev_t gdbstub_console_dev(struct console *con)
{
return MKDEV(1, 3); /* /dev/null */
}
static struct console gdbstub_console = {
.name = "gdb",
.write = gdbstub_console_write,
.device = gdbstub_console_dev,
.flags = CON_PRINTBUFFER,
.index = -1,
};
#endif
/*
* Convert the memory pointed to by mem into hex, placing result in buf.
* - if successful, return a pointer to the last char put in buf (NUL)
* - in case of mem fault, return NULL
* may_fault is non-zero if we are reading from arbitrary memory, but is
* currently not used.
*/
static
unsigned char *mem2hex(const void *_mem, char *buf, int count, int may_fault)
{
const u8 *mem = _mem;
u8 ch[4];
if ((u32) mem & 1 && count >= 1) {
if (gdbstub_read_byte(mem, ch) != 0)
return 0;
buf = hex_byte_pack(buf, ch[0]);
mem++;
count--;
}
if ((u32) mem & 3 && count >= 2) {
if (gdbstub_read_word(mem, ch) != 0)
return 0;
buf = hex_byte_pack(buf, ch[0]);
buf = hex_byte_pack(buf, ch[1]);
mem += 2;
count -= 2;
}
while (count >= 4) {
if (gdbstub_read_dword(mem, ch) != 0)
return 0;
buf = hex_byte_pack(buf, ch[0]);
buf = hex_byte_pack(buf, ch[1]);
buf = hex_byte_pack(buf, ch[2]);
buf = hex_byte_pack(buf, ch[3]);
mem += 4;
count -= 4;
}
if (count >= 2) {
if (gdbstub_read_word(mem, ch) != 0)
return 0;
buf = hex_byte_pack(buf, ch[0]);
buf = hex_byte_pack(buf, ch[1]);
mem += 2;
count -= 2;
}
if (count >= 1) {
if (gdbstub_read_byte(mem, ch) != 0)
return 0;
buf = hex_byte_pack(buf, ch[0]);
}
*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
* may_fault is non-zero if we are reading from arbitrary memory, but is
* currently not used.
*/
static
const char *hex2mem(const char *buf, void *_mem, int count, int may_fault)
{
u8 *mem = _mem;
union {
u32 val;
u8 b[4];
} ch;
if ((u32) mem & 1 && count >= 1) {
ch.b[0] = hex(*buf++) << 4;
ch.b[0] |= hex(*buf++);
if (gdbstub_write_byte(ch.val, mem) != 0)
return 0;
mem++;
count--;
}
if ((u32) mem & 3 && count >= 2) {
ch.b[0] = hex(*buf++) << 4;
ch.b[0] |= hex(*buf++);
ch.b[1] = hex(*buf++) << 4;
ch.b[1] |= hex(*buf++);
if (gdbstub_write_word(ch.val, mem) != 0)
return 0;
mem += 2;
count -= 2;
}
while (count >= 4) {
ch.b[0] = hex(*buf++) << 4;
ch.b[0] |= hex(*buf++);
ch.b[1] = hex(*buf++) << 4;
ch.b[1] |= hex(*buf++);
ch.b[2] = hex(*buf++) << 4;
ch.b[2] |= hex(*buf++);
ch.b[3] = hex(*buf++) << 4;
ch.b[3] |= hex(*buf++);
if (gdbstub_write_dword(ch.val, mem) != 0)
return 0;
mem += 4;
count -= 4;
}
if (count >= 2) {
ch.b[0] = hex(*buf++) << 4;
ch.b[0] |= hex(*buf++);
ch.b[1] = hex(*buf++) << 4;
ch.b[1] |= hex(*buf++);
if (gdbstub_write_word(ch.val, mem) != 0)
return 0;
mem += 2;
count -= 2;
}
if (count >= 1) {
ch.b[0] = hex(*buf++) << 4;
ch.b[0] |= hex(*buf++);
if (gdbstub_write_byte(ch.val, mem) != 0)
return 0;
}
return buf;
}
/*
* This table contains the mapping between MN10300 exception codes, and
* signals, which are primarily what GDB understands. It also indicates
* which hardware traps we need to commandeer when initializing the stub.
*/
static const struct excep_to_sig_map {
enum exception_code excep; /* MN10300 exception code */
unsigned char signo; /* Signal that we map this into */
} excep_to_sig_map[] = {
{ EXCEP_ITLBMISS, SIGSEGV },
{ EXCEP_DTLBMISS, SIGSEGV },
{ EXCEP_TRAP, SIGTRAP },
{ EXCEP_ISTEP, SIGTRAP },
{ EXCEP_IBREAK, SIGTRAP },
{ EXCEP_OBREAK, SIGTRAP },
{ EXCEP_UNIMPINS, SIGILL },
{ EXCEP_UNIMPEXINS, SIGILL },
{ EXCEP_MEMERR, SIGSEGV },
{ EXCEP_MISALIGN, SIGSEGV },
{ EXCEP_BUSERROR, SIGBUS },
{ EXCEP_ILLINSACC, SIGSEGV },
{ EXCEP_ILLDATACC, SIGSEGV },
{ EXCEP_IOINSACC, SIGSEGV },
{ EXCEP_PRIVINSACC, SIGSEGV },
{ EXCEP_PRIVDATACC, SIGSEGV },
{ EXCEP_FPU_DISABLED, SIGFPE },
{ EXCEP_FPU_UNIMPINS, SIGFPE },
{ EXCEP_FPU_OPERATION, SIGFPE },
{ EXCEP_WDT, SIGALRM },
{ EXCEP_NMI, SIGQUIT },
{ EXCEP_IRQ_LEVEL0, SIGINT },
{ EXCEP_IRQ_LEVEL1, SIGINT },
{ EXCEP_IRQ_LEVEL2, SIGINT },
{ EXCEP_IRQ_LEVEL3, SIGINT },
{ EXCEP_IRQ_LEVEL4, SIGINT },
{ EXCEP_IRQ_LEVEL5, SIGINT },
{ EXCEP_IRQ_LEVEL6, SIGINT },
{ 0, 0}
};
/*
* convert the MN10300 exception code into a UNIX signal number
*/
static int computeSignal(enum exception_code excep)
{
const struct excep_to_sig_map *map;
for (map = excep_to_sig_map; map->signo; map++)
if (map->excep == excep)
return map->signo;
return SIGHUP; /* default for things we don't know about */
}
static u32 gdbstub_fpcr, gdbstub_fpufs_array[32];
/*
*
*/
static void gdbstub_store_fpu(void)
{
#ifdef CONFIG_FPU
asm volatile(
"or %2,epsw\n"
#ifdef CONFIG_MN10300_PROC_MN103E010
"nop\n"
"nop\n"
#endif
"mov %1, a1\n"
"fmov fs0, (a1+)\n"
"fmov fs1, (a1+)\n"
"fmov fs2, (a1+)\n"
"fmov fs3, (a1+)\n"
"fmov fs4, (a1+)\n"
"fmov fs5, (a1+)\n"
"fmov fs6, (a1+)\n"
"fmov fs7, (a1+)\n"
"fmov fs8, (a1+)\n"
"fmov fs9, (a1+)\n"
"fmov fs10, (a1+)\n"
"fmov fs11, (a1+)\n"
"fmov fs12, (a1+)\n"
"fmov fs13, (a1+)\n"
"fmov fs14, (a1+)\n"
"fmov fs15, (a1+)\n"
"fmov fs16, (a1+)\n"
"fmov fs17, (a1+)\n"
"fmov fs18, (a1+)\n"
"fmov fs19, (a1+)\n"
"fmov fs20, (a1+)\n"
"fmov fs21, (a1+)\n"
"fmov fs22, (a1+)\n"
"fmov fs23, (a1+)\n"
"fmov fs24, (a1+)\n"
"fmov fs25, (a1+)\n"
"fmov fs26, (a1+)\n"
"fmov fs27, (a1+)\n"
"fmov fs28, (a1+)\n"
"fmov fs29, (a1+)\n"
"fmov fs30, (a1+)\n"
"fmov fs31, (a1+)\n"
"fmov fpcr, %0\n"
: "=d"(gdbstub_fpcr)
: "g" (&gdbstub_fpufs_array), "i"(EPSW_FE)
: "a1"
);
#endif
}
/*
*
*/
static void gdbstub_load_fpu(void)
{
#ifdef CONFIG_FPU
asm volatile(
"or %1,epsw\n"
#ifdef CONFIG_MN10300_PROC_MN103E010
"nop\n"
"nop\n"
#endif
"mov %0, a1\n"
"fmov (a1+), fs0\n"
"fmov (a1+), fs1\n"
"fmov (a1+), fs2\n"
"fmov (a1+), fs3\n"
"fmov (a1+), fs4\n"
"fmov (a1+), fs5\n"
"fmov (a1+), fs6\n"
"fmov (a1+), fs7\n"
"fmov (a1+), fs8\n"
"fmov (a1+), fs9\n"
"fmov (a1+), fs10\n"
"fmov (a1+), fs11\n"
"fmov (a1+), fs12\n"
"fmov (a1+), fs13\n"
"fmov (a1+), fs14\n"
"fmov (a1+), fs15\n"
"fmov (a1+), fs16\n"
"fmov (a1+), fs17\n"
"fmov (a1+), fs18\n"
"fmov (a1+), fs19\n"
"fmov (a1+), fs20\n"
"fmov (a1+), fs21\n"
"fmov (a1+), fs22\n"
"fmov (a1+), fs23\n"
"fmov (a1+), fs24\n"
"fmov (a1+), fs25\n"
"fmov (a1+), fs26\n"
"fmov (a1+), fs27\n"
"fmov (a1+), fs28\n"
"fmov (a1+), fs29\n"
"fmov (a1+), fs30\n"
"fmov (a1+), fs31\n"
"fmov %2, fpcr\n"
:
: "g" (&gdbstub_fpufs_array), "i"(EPSW_FE), "d"(gdbstub_fpcr)
: "a1"
);
#endif
}
/*
* set a software breakpoint
*/
int gdbstub_set_breakpoint(u8 *addr, int len)
{
int bkpt, loop, xloop;
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
len = (len + 1) & ~1;
#endif
gdbstub_bkpt("setbkpt(%p,%d)\n", addr, len);
for (bkpt = 255; bkpt >= 0; bkpt--)
if (!gdbstub_bkpts[bkpt].addr)
break;
if (bkpt < 0)
return -ENOSPC;
for (loop = 0; loop < len; loop++)
if (gdbstub_read_byte(&addr[loop],
&gdbstub_bkpts[bkpt].origbytes[loop]
) < 0)
return -EFAULT;
gdbstub_flush_caches = 1;
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
for (loop = 0; loop < len; loop++)
if (gdbstub_write_byte(0xF7, &addr[loop]) < 0)
goto restore;
#else
for (loop = 0; loop < len; loop++)
if (gdbstub_write_byte(0xFF, &addr[loop]) < 0)
goto restore;
#endif
gdbstub_bkpts[bkpt].addr = addr;
gdbstub_bkpts[bkpt].len = len;
gdbstub_bkpt("Set BKPT[%02x]: %p-%p {%02x%02x%02x%02x%02x%02x%02x}\n",
bkpt,
gdbstub_bkpts[bkpt].addr,
gdbstub_bkpts[bkpt].addr + gdbstub_bkpts[bkpt].len - 1,
gdbstub_bkpts[bkpt].origbytes[0],
gdbstub_bkpts[bkpt].origbytes[1],
gdbstub_bkpts[bkpt].origbytes[2],
gdbstub_bkpts[bkpt].origbytes[3],
gdbstub_bkpts[bkpt].origbytes[4],
gdbstub_bkpts[bkpt].origbytes[5],
gdbstub_bkpts[bkpt].origbytes[6]
);
return 0;
restore:
for (xloop = 0; xloop < loop; xloop++)
gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[xloop],
addr + xloop);
return -EFAULT;
}
/*
* clear a software breakpoint
*/
int gdbstub_clear_breakpoint(u8 *addr, int len)
{
int bkpt, loop;
#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
len = (len + 1) & ~1;
#endif
gdbstub_bkpt("clearbkpt(%p,%d)\n", addr, len);
for (bkpt = 255; bkpt >= 0; bkpt--)
if (gdbstub_bkpts[bkpt].addr == addr &&
gdbstub_bkpts[bkpt].len == len)
break;
if (bkpt < 0)
return -ENOENT;
gdbstub_bkpts[bkpt].addr = NULL;
gdbstub_flush_caches = 1;
for (loop = 0; loop < len; loop++)
if (gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[loop],
addr + loop) < 0)
return -EFAULT;
return 0;
}
/*
* This function does all command processing for interfacing to gdb
* - returns 0 if the exception should be skipped, -ERROR otherwise.
*/
static int gdbstub(struct pt_regs *regs, enum exception_code excep)
{
unsigned long *stack;
unsigned long epsw, mdr;
uint32_t zero, ssp;
uint8_t broke;
char *ptr;
int sigval;
int addr;
int length;
int loop;
if (excep == EXCEP_FPU_DISABLED)
return -ENOTSUPP;
gdbstub_flush_caches = 0;
mn10300_set_gdbleds(1);
asm volatile("mov mdr,%0" : "=d"(mdr));
local_save_flags(epsw);
arch_local_change_intr_mask_level(
NUM2EPSW_IM(CONFIG_DEBUGGER_IRQ_LEVEL + 1));
gdbstub_store_fpu();
#ifdef CONFIG_GDBSTUB_IMMEDIATE
/* skip the initial pause loop */
if (regs->pc == (unsigned long) __gdbstub_pause)
regs->pc = (unsigned long) start_kernel;
#endif
/* if we were single stepping, restore the opcodes hoisted for the
* breakpoint[s] */
broke = 0;
#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
if ((step_bp[0].addr && step_bp[0].addr == (u8 *) regs->pc) ||
(step_bp[1].addr && step_bp[1].addr == (u8 *) regs->pc))
broke = 1;
__gdbstub_restore_bp();
#endif
if (gdbstub_rx_unget) {
sigval = SIGINT;
if (gdbstub_rx_unget != 3)
goto packet_waiting;
gdbstub_rx_unget = 0;
}
stack = (unsigned long *) regs->sp;
sigval = broke ? SIGTRAP : computeSignal(excep);
/* send information about a BUG() */
if (!user_mode(regs) && excep == EXCEP_SYSCALL15) {
const struct bug_entry *bug;
bug = find_bug(regs->pc);
if (bug)
goto found_bug;
length = snprintf(trans_buffer, sizeof(trans_buffer),
"BUG() at address %lx\n", regs->pc);
goto send_bug_pkt;
found_bug:
length = snprintf(trans_buffer, sizeof(trans_buffer),
"BUG() at address %lx (%s:%d)\n",
regs->pc, bug->file, bug->line);
send_bug_pkt:
ptr = output_buffer;
*ptr++ = 'O';
ptr = mem2hex(trans_buffer, ptr, length, 0);
*ptr = 0;
putpacket(output_buffer);
regs->pc -= 2;
sigval = SIGABRT;
} else if (regs->pc == (unsigned long) __gdbstub_bug_trap) {
regs->pc = regs->mdr;
sigval = SIGABRT;
}
/*
* send a message to the debugger's user saying what happened if it may
* not be clear cut (we can't map exceptions onto signals properly)
*/
if (sigval != SIGINT && sigval != SIGTRAP && sigval != SIGILL) {
static const char title[] = "Excep ", tbcberr[] = "BCBERR ";
static const char crlf[] = "\r\n";
char hx;
u32 bcberr = BCBERR;
ptr = output_buffer;
*ptr++ = 'O';
ptr = mem2hex(title, ptr, sizeof(title) - 1, 0);
hx = hex_asc_hi(excep >> 8);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(excep >> 8);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_hi(excep);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(excep);
ptr = hex_byte_pack(ptr, hx);
ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
*ptr = 0;
putpacket(output_buffer); /* send it off... */
/* BCBERR */
ptr = output_buffer;
*ptr++ = 'O';
ptr = mem2hex(tbcberr, ptr, sizeof(tbcberr) - 1, 0);
hx = hex_asc_hi(bcberr >> 24);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(bcberr >> 24);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_hi(bcberr >> 16);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(bcberr >> 16);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_hi(bcberr >> 8);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(bcberr >> 8);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_hi(bcberr);
ptr = hex_byte_pack(ptr, hx);
hx = hex_asc_lo(bcberr);
ptr = hex_byte_pack(ptr, hx);
ptr = mem2hex(crlf, ptr, sizeof(crlf) - 1, 0);
*ptr = 0;
putpacket(output_buffer); /* send it off... */
}
/*
* tell the debugger that an exception has occurred
*/
ptr = output_buffer;
/*
* Send trap type (converted to signal)
*/
*ptr++ = 'T';
ptr = hex_byte_pack(ptr, sigval);
/*
* Send Error PC
*/
ptr = hex_byte_pack(ptr, GDB_REGID_PC);
*ptr++ = ':';
ptr = mem2hex(&regs->pc, ptr, 4, 0);
*ptr++ = ';';
/*
* Send frame pointer
*/
ptr = hex_byte_pack(ptr, GDB_REGID_FP);
*ptr++ = ':';
ptr = mem2hex(&regs->a3, ptr, 4, 0);
*ptr++ = ';';
/*
* Send stack pointer
*/
ssp = (unsigned long) (regs + 1);
ptr = hex_byte_pack(ptr, GDB_REGID_SP);
*ptr++ = ':';
ptr = mem2hex(&ssp, ptr, 4, 0);
*ptr++ = ';';
*ptr++ = 0;
putpacket(output_buffer); /* send it off... */
packet_waiting:
/*
* Wait for input from remote GDB
*/
while (1) {
output_buffer[0] = 0;
getpacket(input_buffer);
switch (input_buffer[0]) {
/* request repeat of last signal number */
case '?':
output_buffer[0] = 'S';
output_buffer[1] = hex_asc_hi(sigval);
output_buffer[2] = hex_asc_lo(sigval);
output_buffer[3] = 0;
break;
case 'd':
/* toggle debug flag */
break;
/*
* Return the value of the CPU registers
*/
case 'g':
zero = 0;
ssp = (u32) (regs + 1);
ptr = output_buffer;
ptr = mem2hex(&regs->d0, ptr, 4, 0);
ptr = mem2hex(&regs->d1, ptr, 4, 0);
ptr = mem2hex(&regs->d2, ptr, 4, 0);
ptr = mem2hex(&regs->d3, ptr, 4, 0);
ptr = mem2hex(&regs->a0, ptr, 4, 0);
ptr = mem2hex(&regs->a1, ptr, 4, 0);
ptr = mem2hex(&regs->a2, ptr, 4, 0);
ptr = mem2hex(&regs->a3, ptr, 4, 0);
ptr = mem2hex(&ssp, ptr, 4, 0); /* 8 */
ptr = mem2hex(&regs->pc, ptr, 4, 0);
ptr = mem2hex(&regs->mdr, ptr, 4, 0);
ptr = mem2hex(&regs->epsw, ptr, 4, 0);
ptr = mem2hex(&regs->lir, ptr, 4, 0);
ptr = mem2hex(&regs->lar, ptr, 4, 0);
ptr = mem2hex(&regs->mdrq, ptr, 4, 0);
ptr = mem2hex(&regs->e0, ptr, 4, 0); /* 15 */
ptr = mem2hex(&regs->e1, ptr, 4, 0);
ptr = mem2hex(&regs->e2, ptr, 4, 0);
ptr = mem2hex(&regs->e3, ptr, 4, 0);
ptr = mem2hex(&regs->e4, ptr, 4, 0);
ptr = mem2hex(&regs->e5, ptr, 4, 0);
ptr = mem2hex(&regs->e6, ptr, 4, 0);
ptr = mem2hex(&regs->e7, ptr, 4, 0);
ptr = mem2hex(&ssp, ptr, 4, 0);
ptr = mem2hex(&regs, ptr, 4, 0);
ptr = mem2hex(&regs->sp, ptr, 4, 0);
ptr = mem2hex(&regs->mcrh, ptr, 4, 0); /* 26 */
ptr = mem2hex(&regs->mcrl, ptr, 4, 0);
ptr = mem2hex(&regs->mcvf, ptr, 4, 0);
ptr = mem2hex(&gdbstub_fpcr, ptr, 4, 0); /* 29 - FPCR */
ptr = mem2hex(&zero, ptr, 4, 0);
ptr = mem2hex(&zero, ptr, 4, 0);
for (loop = 0; loop < 32; loop++)
ptr = mem2hex(&gdbstub_fpufs_array[loop],
ptr, 4, 0); /* 32 - FS0-31 */
break;
/*
* set the value of the CPU registers - return OK
*/
case 'G':
{
const char *ptr;
ptr = &input_buffer[1];
ptr = hex2mem(ptr, &regs->d0, 4, 0);
ptr = hex2mem(ptr, &regs->d1, 4, 0);
ptr = hex2mem(ptr, &regs->d2, 4, 0);
ptr = hex2mem(ptr, &regs->d3, 4, 0);
ptr = hex2mem(ptr, &regs->a0, 4, 0);
ptr = hex2mem(ptr, &regs->a1, 4, 0);
ptr = hex2mem(ptr, &regs->a2, 4, 0);
ptr = hex2mem(ptr, &regs->a3, 4, 0);
ptr = hex2mem(ptr, &ssp, 4, 0); /* 8 */
ptr = hex2mem(ptr, &regs->pc, 4, 0);
ptr = hex2mem(ptr, &regs->mdr, 4, 0);
ptr = hex2mem(ptr, &regs->epsw, 4, 0);
ptr = hex2mem(ptr, &regs->lir, 4, 0);
ptr = hex2mem(ptr, &regs->lar, 4, 0);
ptr = hex2mem(ptr, &regs->mdrq, 4, 0);
ptr = hex2mem(ptr, &regs->e0, 4, 0); /* 15 */
ptr = hex2mem(ptr, &regs->e1, 4, 0);
ptr = hex2mem(ptr, &regs->e2, 4, 0);
ptr = hex2mem(ptr, &regs->e3, 4, 0);
ptr = hex2mem(ptr, &regs->e4, 4, 0);
ptr = hex2mem(ptr, &regs->e5, 4, 0);
ptr = hex2mem(ptr, &regs->e6, 4, 0);
ptr = hex2mem(ptr, &regs->e7, 4, 0);
ptr = hex2mem(ptr, &ssp, 4, 0);
ptr = hex2mem(ptr, &zero, 4, 0);
ptr = hex2mem(ptr, &regs->sp, 4, 0);
ptr = hex2mem(ptr, &regs->mcrh, 4, 0); /* 26 */
ptr = hex2mem(ptr, &regs->mcrl, 4, 0);
ptr = hex2mem(ptr, &regs->mcvf, 4, 0);
ptr = hex2mem(ptr, &zero, 4, 0); /* 29 - FPCR */
ptr = hex2mem(ptr, &zero, 4, 0);
ptr = hex2mem(ptr, &zero, 4, 0);
for (loop = 0; loop < 32; loop++) /* 32 - FS0-31 */
ptr = hex2mem(ptr, &zero, 4, 0);
#if 0
/*
* See if the stack pointer has moved. If so, then copy
* the saved locals and ins to the new location.
*/
unsigned long *newsp = (unsigned long *) registers[SP];
if (sp != newsp)
sp = memcpy(newsp, sp, 16 * 4);
#endif
gdbstub_strcpy(output_buffer, "OK");
}
break;
/*
* mAA..AA,LLLL Read LLLL bytes at address AA..AA
*/
case 'm':
ptr = &input_buffer[1];
if (hexToInt(&ptr, &addr) &&
*ptr++ == ',' &&
hexToInt(&ptr, &length)
) {
if (mem2hex((char *) addr, output_buffer,
length, 1))
break;
gdbstub_strcpy(output_buffer, "E03");
} else {
gdbstub_strcpy(output_buffer, "E01");
}
break;
/*
* MAA..AA,LLLL: Write LLLL bytes at address AA.AA
* return OK
*/
case 'M':
ptr = &input_buffer[1];
if (hexToInt(&ptr, &addr) &&
*ptr++ == ',' &&
hexToInt(&ptr, &length) &&
*ptr++ == ':'
) {
if (hex2mem(ptr, (char *) addr, length, 1))
gdbstub_strcpy(output_buffer, "OK");
else
gdbstub_strcpy(output_buffer, "E03");
gdbstub_flush_caches = 1;
} else {
gdbstub_strcpy(output_buffer, "E02");
}
break;
/*
* cAA..AA Continue at address AA..AA(optional)
*/
case 'c':
/* try to read optional parameter, pc unchanged if no
* parm */
ptr = &input_buffer[1];
if (hexToInt(&ptr, &addr))
regs->pc = addr;
goto done;
/*
* kill the program
*/
case 'k' :
goto done; /* just continue */
/*
* Reset the whole machine (FIXME: system dependent)
*/
case 'r':
break;
/*
* Step to next instruction
*/
case 's':
/* Using the T flag doesn't seem to perform single
* stepping (it seems to wind up being caught by the
* JTAG unit), so we have to use breakpoints and
* continue instead.
*/
#ifdef CONFIG_GDBSTUB_ALLOW_SINGLE_STEP
if (gdbstub_single_step(regs) < 0)
/* ignore any fault error for now */
gdbstub_printk("unable to set single-step"
" bp\n");
goto done;
#else
gdbstub_strcpy(output_buffer, "E01");
break;
#endif
/*
* Set baud rate (bBB)
*/
case 'b':
do {
int baudrate;
ptr = &input_buffer[1];
if (!hexToInt(&ptr, &baudrate)) {
gdbstub_strcpy(output_buffer, "B01");
break;
}
if (baudrate) {
/* ACK before changing speed */
putpacket("OK");
gdbstub_io_set_baud(baudrate);
}
} while (0);
break;
/*
* Set breakpoint
*/
case 'Z':
ptr = &input_buffer[1];
if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
!hexToInt(&ptr, &addr) || *ptr++ != ',' ||
!hexToInt(&ptr, &length)
) {
gdbstub_strcpy(output_buffer, "E01");
break;
}
/* only support software breakpoints */
gdbstub_strcpy(output_buffer, "E03");
if (loop != 0 ||
length < 1 ||
length > 7 ||
(unsigned long) addr < 4096)
break;
if (gdbstub_set_breakpoint((u8 *) addr, length) < 0)
break;
gdbstub_strcpy(output_buffer, "OK");
break;
/*
* Clear breakpoint
*/
case 'z':
ptr = &input_buffer[1];
if (!hexToInt(&ptr, &loop) || *ptr++ != ',' ||
!hexToInt(&ptr, &addr) || *ptr++ != ',' ||
!hexToInt(&ptr, &length)
) {
gdbstub_strcpy(output_buffer, "E01");
break;
}
/* only support software breakpoints */
gdbstub_strcpy(output_buffer, "E03");
if (loop != 0 ||
length < 1 ||
length > 7 ||
(unsigned long) addr < 4096)
break;
if (gdbstub_clear_breakpoint((u8 *) addr, length) < 0)
break;
gdbstub_strcpy(output_buffer, "OK");
break;
default:
gdbstub_proto("### GDB Unsupported Cmd '%s'\n",
input_buffer);
break;
}
/* reply to the request */
putpacket(output_buffer);
}
done:
/*
* 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.
* NB: We flush both caches, just to be sure...
*/
if (gdbstub_flush_caches)
debugger_local_cache_flushinv();
gdbstub_load_fpu();
mn10300_set_gdbleds(0);
if (excep == EXCEP_NMI)
NMICR = NMICR_NMIF;
touch_softlockup_watchdog();
local_irq_restore(epsw);
return 0;
}
/*
* Determine if we hit a debugger special breakpoint that needs skipping over
* automatically.
*/
int at_debugger_breakpoint(struct pt_regs *regs)
{
return 0;
}
/*
* handle event interception
*/
asmlinkage int debugger_intercept(enum exception_code excep,
int signo, int si_code, struct pt_regs *regs)
{
static u8 notfirst = 1;
int ret;
if (gdbstub_busy)
gdbstub_printk("--> gdbstub reentered itself\n");
gdbstub_busy = 1;
if (notfirst) {
unsigned long mdr;
asm("mov mdr,%0" : "=d"(mdr));
gdbstub_entry(
"--> debugger_intercept(%p,%04x) [MDR=%lx PC=%lx]\n",
regs, excep, mdr, regs->pc);
gdbstub_entry(
"PC: %08lx EPSW: %08lx SSP: %08lx mode: %s\n",
regs->pc, regs->epsw, (unsigned long) &ret,
user_mode(regs) ? "User" : "Super");
gdbstub_entry(
"d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
regs->d0, regs->d1, regs->d2, regs->d3);
gdbstub_entry(
"a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
regs->a0, regs->a1, regs->a2, regs->a3);
gdbstub_entry(
"e0: %08lx e1: %08lx e2: %08lx e3: %08lx\n",
regs->e0, regs->e1, regs->e2, regs->e3);
gdbstub_entry(
"e4: %08lx e5: %08lx e6: %08lx e7: %08lx\n",
regs->e4, regs->e5, regs->e6, regs->e7);
gdbstub_entry(
"lar: %08lx lir: %08lx mdr: %08lx usp: %08lx\n",
regs->lar, regs->lir, regs->mdr, regs->sp);
gdbstub_entry(
"cvf: %08lx crl: %08lx crh: %08lx drq: %08lx\n",
regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
gdbstub_entry(
"threadinfo=%p task=%p)\n",
current_thread_info(), current);
} else {
notfirst = 1;
}
ret = gdbstub(regs, excep);
gdbstub_entry("<-- debugger_intercept()\n");
gdbstub_busy = 0;
return ret;
}
/*
* handle the GDB stub itself causing an exception
*/
asmlinkage void gdbstub_exception(struct pt_regs *regs,
enum exception_code excep)
{
unsigned long mdr;
asm("mov mdr,%0" : "=d"(mdr));
gdbstub_entry("--> gdbstub exception({%p},%04x) [MDR=%lx]\n",
regs, excep, mdr);
while ((unsigned long) regs == 0xffffffff) {}
/* handle guarded memory accesses where we know it might fault */
if (regs->pc == (unsigned) gdbstub_read_byte_guard) {
regs->pc = (unsigned) gdbstub_read_byte_cont;
goto fault;
}
if (regs->pc == (unsigned) gdbstub_read_word_guard) {
regs->pc = (unsigned) gdbstub_read_word_cont;
goto fault;
}
if (regs->pc == (unsigned) gdbstub_read_dword_guard) {
regs->pc = (unsigned) gdbstub_read_dword_cont;
goto fault;
}
if (regs->pc == (unsigned) gdbstub_write_byte_guard) {
regs->pc = (unsigned) gdbstub_write_byte_cont;
goto fault;
}
if (regs->pc == (unsigned) gdbstub_write_word_guard) {
regs->pc = (unsigned) gdbstub_write_word_cont;
goto fault;
}
if (regs->pc == (unsigned) gdbstub_write_dword_guard) {
regs->pc = (unsigned) gdbstub_write_dword_cont;
goto fault;
}
gdbstub_printk("\n### GDB stub caused an exception ###\n");
/* something went horribly wrong */
console_verbose();
show_registers(regs);
panic("GDB Stub caused an unexpected exception - can't continue\n");
/* we caught an attempt by the stub to access silly memory */
fault:
gdbstub_entry("<-- gdbstub exception() = EFAULT\n");
regs->d0 = -EFAULT;
return;
}
/*
* send an exit message to GDB
*/
void gdbstub_exit(int status)
{
unsigned char checksum;
unsigned char ch;
int count;
gdbstub_busy = 1;
output_buffer[0] = 'W';
output_buffer[1] = hex_asc_hi(status);
output_buffer[2] = hex_asc_lo(status);
output_buffer[3] = 0;
gdbstub_io_tx_char('$');
checksum = 0;
count = 0;
while ((ch = output_buffer[count]) != 0) {
gdbstub_io_tx_char(ch);
checksum += ch;
count += 1;
}
gdbstub_io_tx_char('#');
gdbstub_io_tx_char(hex_asc_hi(checksum));
gdbstub_io_tx_char(hex_asc_lo(checksum));
/* make sure the output is flushed, or else RedBoot might clobber it */
gdbstub_io_tx_flush();
gdbstub_busy = 0;
}
/*
* initialise the GDB stub
*/
asmlinkage void __init gdbstub_init(void)
{
#ifdef CONFIG_GDBSTUB_IMMEDIATE
unsigned char ch;
int ret;
#endif
gdbstub_busy = 1;
printk(KERN_INFO "%s", gdbstub_banner);
gdbstub_io_init();
gdbstub_entry("--> gdbstub_init\n");
/* try to talk to GDB (or anyone insane enough to want to type GDB
* protocol by hand) */
gdbstub_io("### GDB Tx ACK\n");
gdbstub_io_tx_char('+'); /* 'hello world' */
#ifdef CONFIG_GDBSTUB_IMMEDIATE
gdbstub_printk("GDB Stub waiting for packet\n");
/* in case GDB is started before us, ACK any packets that are already
* sitting there (presumably "$?#xx")
*/
do { gdbstub_io_rx_char(&ch, 0); } while (ch != '$');
do { gdbstub_io_rx_char(&ch, 0); } while (ch != '#');
/* eat first csum byte */
do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
/* eat second csum byte */
do { ret = gdbstub_io_rx_char(&ch, 0); } while (ret != 0);
gdbstub_io("### GDB Tx NAK\n");
gdbstub_io_tx_char('-'); /* NAK it */
#else
printk("GDB Stub ready\n");
#endif
gdbstub_busy = 0;
gdbstub_entry("<-- gdbstub_init\n");
}
/*
* register the console at a more appropriate time
*/
#ifdef CONFIG_GDBSTUB_CONSOLE
static int __init gdbstub_postinit(void)
{
printk(KERN_NOTICE "registering console\n");
register_console(&gdbstub_console);
return 0;
}
__initcall(gdbstub_postinit);
#endif
/*
* handle character reception on GDB serial port
* - jump into the GDB stub if BREAK is detected on the serial line
*/
asmlinkage void gdbstub_rx_irq(struct pt_regs *regs, enum exception_code excep)
{
char ch;
int ret;
gdbstub_entry("--> gdbstub_rx_irq\n");
do {
ret = gdbstub_io_rx_char(&ch, 1);
if (ret != -EIO && ret != -EAGAIN) {
if (ret != -EINTR)
gdbstub_rx_unget = ch;
gdbstub(regs, excep);
}
} while (ret != -EAGAIN);
gdbstub_entry("<-- gdbstub_rx_irq\n");
}
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