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linux/arch/cris/arch-v10/kernel/kgdb.c

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/*!**************************************************************************
*!
*! FILE NAME : kgdb.c
*!
*! DESCRIPTION: Implementation of the gdb stub with respect to ETRAX 100.
*! It is a mix of arch/m68k/kernel/kgdb.c and cris_stub.c.
*!
*!---------------------------------------------------------------------------
*! HISTORY
*!
*! DATE NAME CHANGES
*! ---- ---- -------
*! Apr 26 1999 Hendrik Ruijter Initial version.
*! May 6 1999 Hendrik Ruijter Removed call to strlen in libc and removed
*! struct assignment as it generates calls to
*! memcpy in libc.
*! Jun 17 1999 Hendrik Ruijter Added gdb 4.18 support. 'X', 'qC' and 'qL'.
*! Jul 21 1999 Bjorn Wesen eLinux port
*!
*!---------------------------------------------------------------------------
*!
*! (C) Copyright 1999, Axis Communications AB, LUND, SWEDEN
*!
*!**************************************************************************/
/* @(#) cris_stub.c 1.3 06/17/99 */
/*
* kgdb usage notes:
* -----------------
*
* If you select CONFIG_ETRAX_KGDB in the configuration, the kernel will be
* built with different gcc flags: "-g" is added to get debug infos, and
* "-fomit-frame-pointer" is omitted to make debugging easier. Since the
* resulting kernel will be quite big (approx. > 7 MB), it will be stripped
* before compresion. Such a kernel will behave just as usually, except if
* given a "debug=<device>" command line option. (Only serial devices are
* allowed for <device>, i.e. no printers or the like; possible values are
* machine depedend and are the same as for the usual debug device, the one
* for logging kernel messages.) If that option is given and the device can be
* initialized, the kernel will connect to the remote gdb in trap_init(). The
* serial parameters are fixed to 8N1 and 115200 bps, for easyness of
* implementation.
*
* To start a debugging session, start that gdb with the debugging kernel
* image (the one with the symbols, vmlinux.debug) named on the command line.
* This file will be used by gdb to get symbol and debugging infos about the
* kernel. Next, select remote debug mode by
* target remote <device>
* where <device> is the name of the serial device over which the debugged
* machine is connected. Maybe you have to adjust the baud rate by
* set remotebaud <rate>
* or also other parameters with stty:
* shell stty ... </dev/...
* If the kernel to debug has already booted, it waited for gdb and now
* connects, and you'll see a breakpoint being reported. If the kernel isn't
* running yet, start it now. The order of gdb and the kernel doesn't matter.
* Another thing worth knowing about in the getting-started phase is how to
* debug the remote protocol itself. This is activated with
* set remotedebug 1
* gdb will then print out each packet sent or received. You'll also get some
* messages about the gdb stub on the console of the debugged machine.
*
* If all that works, you can use lots of the usual debugging techniques on
* the kernel, e.g. inspecting and changing variables/memory, setting
* breakpoints, single stepping and so on. It's also possible to interrupt the
* debugged kernel by pressing C-c in gdb. Have fun! :-)
*
* The gdb stub is entered (and thus the remote gdb gets control) in the
* following situations:
*
* - If breakpoint() is called. This is just after kgdb initialization, or if
* a breakpoint() call has been put somewhere into the kernel source.
* (Breakpoints can of course also be set the usual way in gdb.)
* In eLinux, we call breakpoint() in init/main.c after IRQ initialization.
*
* - If there is a kernel exception, i.e. bad_super_trap() or die_if_kernel()
* are entered. All the CPU exceptions are mapped to (more or less..., see
* the hard_trap_info array below) appropriate signal, which are reported
* to gdb. die_if_kernel() is usually called after some kind of access
* error and thus is reported as SIGSEGV.
*
* - When panic() is called. This is reported as SIGABRT.
*
* - If C-c is received over the serial line, which is treated as
* SIGINT.
*
* Of course, all these signals are just faked for gdb, since there is no
* signal concept as such for the kernel. It also isn't possible --obviously--
* to set signal handlers from inside gdb, or restart the kernel with a
* signal.
*
* Current limitations:
*
* - While the kernel is stopped, interrupts are disabled for safety reasons
* (i.e., variables not changing magically or the like). But this also
* means that the clock isn't running anymore, and that interrupts from the
* hardware may get lost/not be served in time. This can cause some device
* errors...
*
* - When single-stepping, only one instruction of the current thread is
* executed, but interrupts are allowed for that time and will be serviced
* if pending. Be prepared for that.
*
* - All debugging happens in kernel virtual address space. There's no way to
* access physical memory not mapped in kernel space, or to access user
* space. A way to work around this is using get_user_long & Co. in gdb
* expressions, but only for the current process.
*
* - Interrupting the kernel only works if interrupts are currently allowed,
* and the interrupt of the serial line isn't blocked by some other means
* (IPL too high, disabled, ...)
*
* - The gdb stub is currently not reentrant, i.e. errors that happen therein
* (e.g. accessing invalid memory) may not be caught correctly. This could
* be removed in future by introducing a stack of struct registers.
*
*/
/*
* To enable debugger support, two things need to happen. One, a
* call to kgdb_init() 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().
*
* 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/string.h>
#include <linux/signal.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/linkage.h>
#include <linux/reboot.h>
#include <asm/setup.h>
#include <asm/ptrace.h>
#include <arch/svinto.h>
#include <asm/irq.h>
static int kgdb_started = 0;
/********************************* Register image ****************************/
/* Use the order of registers as defined in "AXIS ETRAX CRIS Programmer's
Reference", p. 1-1, with the additional register definitions of the
ETRAX 100LX in cris-opc.h.
There are 16 general 32-bit registers, R0-R15, where R14 is the stack
pointer, SP, and R15 is the program counter, PC.
There are 16 special registers, P0-P15, where three of the unimplemented
registers, P0, P4 and P8, are reserved as zero-registers. A read from
any of these registers returns zero and a write has no effect. */
typedef
struct register_image
{
/* Offset */
unsigned int r0; /* 0x00 */
unsigned int r1; /* 0x04 */
unsigned int r2; /* 0x08 */
unsigned int r3; /* 0x0C */
unsigned int r4; /* 0x10 */
unsigned int r5; /* 0x14 */
unsigned int r6; /* 0x18 */
unsigned int r7; /* 0x1C */
unsigned int r8; /* 0x20 Frame pointer */
unsigned int r9; /* 0x24 */
unsigned int r10; /* 0x28 */
unsigned int r11; /* 0x2C */
unsigned int r12; /* 0x30 */
unsigned int r13; /* 0x34 */
unsigned int sp; /* 0x38 Stack pointer */
unsigned int pc; /* 0x3C Program counter */
unsigned char p0; /* 0x40 8-bit zero-register */
unsigned char vr; /* 0x41 Version register */
unsigned short p4; /* 0x42 16-bit zero-register */
unsigned short ccr; /* 0x44 Condition code register */
unsigned int mof; /* 0x46 Multiply overflow register */
unsigned int p8; /* 0x4A 32-bit zero-register */
unsigned int ibr; /* 0x4E Interrupt base register */
unsigned int irp; /* 0x52 Interrupt return pointer */
unsigned int srp; /* 0x56 Subroutine return pointer */
unsigned int bar; /* 0x5A Breakpoint address register */
unsigned int dccr; /* 0x5E Double condition code register */
unsigned int brp; /* 0x62 Breakpoint return pointer (pc in caller) */
unsigned int usp; /* 0x66 User mode stack pointer */
} registers;
/* Serial port, reads one character. ETRAX 100 specific. from debugport.c */
int getDebugChar (void);
/* Serial port, writes one character. ETRAX 100 specific. from debugport.c */
void putDebugChar (int val);
void enableDebugIRQ (void);
/******************** Prototypes for global functions. ***********************/
/* The string str is prepended with the GDB printout token and sent. */
void putDebugString (const unsigned char *str, int length); /* used by etrax100ser.c */
/* The hook for both static (compiled) and dynamic breakpoints set by GDB.
ETRAX 100 specific. */
void handle_breakpoint (void); /* used by irq.c */
/* The hook for an interrupt generated by GDB. ETRAX 100 specific. */
void handle_interrupt (void); /* used by irq.c */
/* A static breakpoint to be used at startup. */
void breakpoint (void); /* called by init/main.c */
/* From osys_int.c, executing_task contains the number of the current
executing task in osys. Does not know of object-oriented threads. */
extern unsigned char executing_task;
/* The number of characters used for a 64 bit thread identifier. */
#define HEXCHARS_IN_THREAD_ID 16
/********************************** Packet I/O ******************************/
/* BUFMAX defines the maximum number of characters in
inbound/outbound buffers */
#define BUFMAX 512
/* Run-length encoding maximum length. Send 64 at most. */
#define RUNLENMAX 64
/* The inbound/outbound buffers used in packet I/O */
static char remcomInBuffer[BUFMAX];
static char remcomOutBuffer[BUFMAX];
/* Error and warning messages. */
enum error_type
{
SUCCESS, E01, E02, E03, E04, E05, E06, E07
};
static char *error_message[] =
{
"",
"E01 Set current or general thread - H[c,g] - internal error.",
"E02 Change register content - P - cannot change read-only register.",
"E03 Thread is not alive.", /* T, not used. */
"E04 The command is not supported - [s,C,S,!,R,d,r] - internal error.",
"E05 Change register content - P - the register is not implemented..",
"E06 Change memory content - M - internal error.",
"E07 Change register content - P - the register is not stored on the stack"
};
/********************************* Register image ****************************/
/* Use the order of registers as defined in "AXIS ETRAX CRIS Programmer's
Reference", p. 1-1, with the additional register definitions of the
ETRAX 100LX in cris-opc.h.
There are 16 general 32-bit registers, R0-R15, where R14 is the stack
pointer, SP, and R15 is the program counter, PC.
There are 16 special registers, P0-P15, where three of the unimplemented
registers, P0, P4 and P8, are reserved as zero-registers. A read from
any of these registers returns zero and a write has no effect. */
enum register_name
{
R0, R1, R2, R3,
R4, R5, R6, R7,
R8, R9, R10, R11,
R12, R13, SP, PC,
P0, VR, P2, P3,
P4, CCR, P6, MOF,
P8, IBR, IRP, SRP,
BAR, DCCR, BRP, USP
};
/* The register sizes of the registers in register_name. An unimplemented register
is designated by size 0 in this array. */
static int register_size[] =
{
4, 4, 4, 4,
4, 4, 4, 4,
4, 4, 4, 4,
4, 4, 4, 4,
1, 1, 0, 0,
2, 2, 0, 4,
4, 4, 4, 4,
4, 4, 4, 4
};
/* Contains the register image of the executing thread in the assembler
part of the code in order to avoid horrible addressing modes. */
registers cris_reg;
/* FIXME: Should this be used? Delete otherwise. */
/* Contains the assumed consistency state of the register image. Uses the
enum error_type for state information. */
static int consistency_status = SUCCESS;
/********************************** Handle exceptions ************************/
/* The variable cris_reg contains the register image associated with the
current_thread_c variable. It is a complete register image created at
entry. The reg_g contains a register image of a task where the general
registers are taken from the stack and all special registers are taken
from the executing task. It is associated with current_thread_g and used
in order to provide access mainly for 'g', 'G' and 'P'.
*/
/********************************** Breakpoint *******************************/
/* Use an internal stack in the breakpoint and interrupt response routines */
#define INTERNAL_STACK_SIZE 1024
char internal_stack[INTERNAL_STACK_SIZE];
/* Due to the breakpoint return pointer, a state variable is needed to keep
track of whether it is a static (compiled) or dynamic (gdb-invoked)
breakpoint to be handled. A static breakpoint uses the content of register
BRP as it is whereas a dynamic breakpoint requires subtraction with 2
in order to execute the instruction. The first breakpoint is static. */
static unsigned char is_dyn_brkp = 0;
/********************************* String library ****************************/
/* Single-step over library functions creates trap loops. */
/* Copy char s2[] to s1[]. */
static char*
gdb_cris_strcpy (char *s1, const char *s2)
{
char *s = s1;
for (s = s1; (*s++ = *s2++) != '\0'; )
;
return (s1);
}
/* Find length of s[]. */
static int
gdb_cris_strlen (const char *s)
{
const char *sc;
for (sc = s; *sc != '\0'; sc++)
;
return (sc - s);
}
/* Find first occurrence of c in s[n]. */
static void*
gdb_cris_memchr (const void *s, int c, int n)
{
const unsigned char uc = c;
const unsigned char *su;
for (su = s; 0 < n; ++su, --n)
if (*su == uc)
return ((void *)su);
return (NULL);
}
/******************************* Standard library ****************************/
/* Single-step over library functions creates trap loops. */
/* Convert string to long. */
static int
gdb_cris_strtol (const char *s, char **endptr, int base)
{
char *s1;
char *sd;
int x = 0;
for (s1 = (char*)s; (sd = gdb_cris_memchr(hex_asc, *s1, base)) != NULL; ++s1)
x = x * base + (sd - hex_asc);
if (endptr)
{
/* Unconverted suffix is stored in endptr unless endptr is NULL. */
*endptr = s1;
}
return x;
}
/********************************** Packet I/O ******************************/
/* Returns the integer equivalent of a hexadecimal character. */
static int
hex (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);
}
/* Convert the memory, pointed to by mem into hexadecimal representation.
Put the result in buf, and return a pointer to the last character
in buf (null). */
static char *
mem2hex(char *buf, unsigned char *mem, int count)
{
int i;
int ch;
if (mem == NULL) {
/* Bogus read from m0. FIXME: What constitutes a valid address? */
for (i = 0; i < count; i++) {
*buf++ = '0';
*buf++ = '0';
}
} else {
/* Valid mem address. */
for (i = 0; i < count; i++) {
ch = *mem++;
buf = hex_byte_pack(buf, ch);
}
}
/* Terminate properly. */
*buf = '\0';
return (buf);
}
/* Convert the array, in hexadecimal representation, pointed to by buf into
binary representation. Put the result in mem, and return a pointer to
the character after the last byte written. */
static unsigned char*
hex2mem (unsigned char *mem, char *buf, int count)
{
int i;
unsigned char ch;
for (i = 0; i < count; i++) {
ch = hex (*buf++) << 4;
ch = ch + hex (*buf++);
*mem++ = ch;
}
return (mem);
}
/* Put the content of the array, in binary representation, pointed to by buf
into memory pointed to by mem, and return a pointer to the character after
the last byte written.
Gdb will escape $, #, and the escape char (0x7d). */
static unsigned char*
bin2mem (unsigned char *mem, unsigned char *buf, int count)
{
int i;
unsigned char *next;
for (i = 0; i < count; i++) {
/* Check for any escaped characters. Be paranoid and
only unescape chars that should be escaped. */
if (*buf == 0x7d) {
next = buf + 1;
if (*next == 0x3 || *next == 0x4 || *next == 0x5D) /* #, $, ESC */
{
buf++;
*buf += 0x20;
}
}
*mem++ = *buf++;
}
return (mem);
}
/* Await the sequence $<data>#<checksum> and store <data> in the array buffer
returned. */
static void
getpacket (char *buffer)
{
unsigned char checksum;
unsigned char xmitcsum;
int i;
int count;
char ch;
do {
while ((ch = getDebugChar ()) != '$')
/* Wait for the start character $ and ignore all other characters */;
checksum = 0;
xmitcsum = -1;
count = 0;
/* Read until a # or the end of the buffer is reached */
while (count < BUFMAX - 1) {
ch = getDebugChar ();
if (ch == '#')
break;
checksum = checksum + ch;
buffer[count] = ch;
count = count + 1;
}
buffer[count] = '\0';
if (ch == '#') {
xmitcsum = hex (getDebugChar ()) << 4;
xmitcsum += hex (getDebugChar ());
if (checksum != xmitcsum) {
/* Wrong checksum */
putDebugChar ('-');
}
else {
/* Correct checksum */
putDebugChar ('+');
/* If sequence characters are received, reply with them */
if (buffer[2] == ':') {
putDebugChar (buffer[0]);
putDebugChar (buffer[1]);
/* Remove the sequence characters from the buffer */
count = gdb_cris_strlen (buffer);
for (i = 3; i <= count; i++)
buffer[i - 3] = buffer[i];
}
}
}
} while (checksum != xmitcsum);
}
/* Send $<data>#<checksum> from the <data> in the array buffer. */
static void
putpacket(char *buffer)
{
int checksum;
int runlen;
int encode;
do {
char *src = buffer;
putDebugChar ('$');
checksum = 0;
while (*src) {
/* Do run length encoding */
putDebugChar (*src);
checksum += *src;
runlen = 0;
while (runlen < RUNLENMAX && *src == src[runlen]) {
runlen++;
}
if (runlen > 3) {
/* Got a useful amount */
putDebugChar ('*');
checksum += '*';
encode = runlen + ' ' - 4;
putDebugChar (encode);
checksum += encode;
src += runlen;
}
else {
src++;
}
}
putDebugChar('#');
putDebugChar(hex_asc_hi(checksum));
putDebugChar(hex_asc_lo(checksum));
} while(kgdb_started && (getDebugChar() != '+'));
}
/* The string str is prepended with the GDB printout token and sent. Required
in traditional implementations. */
void
putDebugString (const unsigned char *str, int length)
{
remcomOutBuffer[0] = 'O';
mem2hex(&remcomOutBuffer[1], (unsigned char *)str, length);
putpacket(remcomOutBuffer);
}
/********************************* Register image ****************************/
/* Write a value to a specified register in the register image of the current
thread. Returns status code SUCCESS, E02 or E05. */
static int
write_register (int regno, char *val)
{
int status = SUCCESS;
registers *current_reg = &cris_reg;
if (regno >= R0 && regno <= PC) {
/* 32-bit register with simple offset. */
hex2mem ((unsigned char *)current_reg + regno * sizeof(unsigned int),
val, sizeof(unsigned int));
}
else if (regno == P0 || regno == VR || regno == P4 || regno == P8) {
/* Do not support read-only registers. */
status = E02;
}
else if (regno == CCR) {
/* 16 bit register with complex offset. (P4 is read-only, P6 is not implemented,
and P7 (MOF) is 32 bits in ETRAX 100LX. */
hex2mem ((unsigned char *)&(current_reg->ccr) + (regno-CCR) * sizeof(unsigned short),
val, sizeof(unsigned short));
}
else if (regno >= MOF && regno <= USP) {
/* 32 bit register with complex offset. (P8 has been taken care of.) */
hex2mem ((unsigned char *)&(current_reg->ibr) + (regno-IBR) * sizeof(unsigned int),
val, sizeof(unsigned int));
}
else {
/* Do not support nonexisting or unimplemented registers (P2, P3, and P6). */
status = E05;
}
return status;
}
/* Read a value from a specified register in the register image. Returns the
value in the register or -1 for non-implemented registers.
Should check consistency_status after a call which may be E05 after changes
in the implementation. */
static int
read_register (char regno, unsigned int *valptr)
{
registers *current_reg = &cris_reg;
if (regno >= R0 && regno <= PC) {
/* 32-bit register with simple offset. */
*valptr = *(unsigned int *)((char *)current_reg + regno * sizeof(unsigned int));
return SUCCESS;
}
else if (regno == P0 || regno == VR) {
/* 8 bit register with complex offset. */
*valptr = (unsigned int)(*(unsigned char *)
((char *)&(current_reg->p0) + (regno-P0) * sizeof(char)));
return SUCCESS;
}
else if (regno == P4 || regno == CCR) {
/* 16 bit register with complex offset. */
*valptr = (unsigned int)(*(unsigned short *)
((char *)&(current_reg->p4) + (regno-P4) * sizeof(unsigned short)));
return SUCCESS;
}
else if (regno >= MOF && regno <= USP) {
/* 32 bit register with complex offset. */
*valptr = *(unsigned int *)((char *)&(current_reg->p8)
+ (regno-P8) * sizeof(unsigned int));
return SUCCESS;
}
else {
/* Do not support nonexisting or unimplemented registers (P2, P3, and P6). */
consistency_status = E05;
return E05;
}
}
/********************************** Handle exceptions ************************/
/* Build and send a response packet in order to inform the host the
stub is stopped. TAAn...:r...;n...:r...;n...:r...;
AA = signal number
n... = register number (hex)
r... = register contents
n... = `thread'
r... = thread process ID. This is a hex integer.
n... = other string not starting with valid hex digit.
gdb should ignore this n,r pair and go on to the next.
This way we can extend the protocol. */
static void
stub_is_stopped(int sigval)
{
char *ptr = remcomOutBuffer;
int regno;
unsigned int reg_cont;
int status;
/* Send trap type (converted to signal) */
*ptr++ = 'T';
ptr = hex_byte_pack(ptr, sigval);
/* Send register contents. We probably only need to send the
* PC, frame pointer and stack pointer here. Other registers will be
* explicitly asked for. But for now, send all.
*/
for (regno = R0; regno <= USP; regno++) {
/* Store n...:r...; for the registers in the buffer. */
status = read_register (regno, &reg_cont);
if (status == SUCCESS) {
ptr = hex_byte_pack(ptr, regno);
*ptr++ = ':';
ptr = mem2hex(ptr, (unsigned char *)&reg_cont,
register_size[regno]);
*ptr++ = ';';
}
}
/* null-terminate and send it off */
*ptr = 0;
putpacket (remcomOutBuffer);
}
/* Performs a complete re-start from scratch. */
static void
kill_restart (void)
{
machine_restart("");
}
/* All expected commands are sent from remote.c. Send a response according
to the description in remote.c. */
void
handle_exception (int sigval)
{
/* Send response. */
stub_is_stopped (sigval);
for (;;) {
remcomOutBuffer[0] = '\0';
getpacket (remcomInBuffer);
switch (remcomInBuffer[0]) {
case 'g':
/* Read registers: g
Success: Each byte of register data is described by two hex digits.
Registers are in the internal order for GDB, and the bytes
in a register are in the same order the machine uses.
Failure: void. */
mem2hex(remcomOutBuffer, (char *)&cris_reg, sizeof(registers));
break;
case 'G':
/* Write registers. GXX..XX
Each byte of register data is described by two hex digits.
Success: OK
Failure: void. */
hex2mem((char *)&cris_reg, &remcomInBuffer[1], sizeof(registers));
gdb_cris_strcpy (remcomOutBuffer, "OK");
break;
case 'P':
/* Write register. Pn...=r...
Write register n..., hex value without 0x, with value r...,
which contains a hex value without 0x and two hex digits
for each byte in the register (target byte order). P1f=11223344 means
set register 31 to 44332211.
Success: OK
Failure: E02, E05 */
{
char *suffix;
int regno = gdb_cris_strtol (&remcomInBuffer[1], &suffix, 16);
int status;
status = write_register (regno, suffix+1);
switch (status) {
case E02:
/* Do not support read-only registers. */
gdb_cris_strcpy (remcomOutBuffer, error_message[E02]);
break;
case E05:
/* Do not support non-existing registers. */
gdb_cris_strcpy (remcomOutBuffer, error_message[E05]);
break;
case E07:
/* Do not support non-existing registers on the stack. */
gdb_cris_strcpy (remcomOutBuffer, error_message[E07]);
break;
default:
/* Valid register number. */
gdb_cris_strcpy (remcomOutBuffer, "OK");
break;
}
}
break;
case 'm':
/* Read from memory. mAA..AA,LLLL
AA..AA is the address and LLLL is the length.
Success: XX..XX is the memory content. Can be fewer bytes than
requested if only part of the data may be read. m6000120a,6c means
retrieve 108 byte from base address 6000120a.
Failure: void. */
{
char *suffix;
unsigned char *addr = (unsigned char *)gdb_cris_strtol(&remcomInBuffer[1],
&suffix, 16); int length = gdb_cris_strtol(suffix+1, 0, 16);
mem2hex(remcomOutBuffer, addr, length);
}
break;
case 'X':
/* Write to memory. XAA..AA,LLLL:XX..XX
AA..AA is the start address, LLLL is the number of bytes, and
XX..XX is the binary data.
Success: OK
Failure: void. */
case 'M':
/* Write to memory. MAA..AA,LLLL:XX..XX
AA..AA is the start address, LLLL is the number of bytes, and
XX..XX is the hexadecimal data.
Success: OK
Failure: void. */
{
char *lenptr;
char *dataptr;
unsigned char *addr = (unsigned char *)gdb_cris_strtol(&remcomInBuffer[1],
&lenptr, 16);
int length = gdb_cris_strtol(lenptr+1, &dataptr, 16);
if (*lenptr == ',' && *dataptr == ':') {
if (remcomInBuffer[0] == 'M') {
hex2mem(addr, dataptr + 1, length);
}
else /* X */ {
bin2mem(addr, dataptr + 1, length);
}
gdb_cris_strcpy (remcomOutBuffer, "OK");
}
else {
gdb_cris_strcpy (remcomOutBuffer, error_message[E06]);
}
}
break;
case 'c':
/* Continue execution. cAA..AA
AA..AA is the address where execution is resumed. If AA..AA is
omitted, resume at the present address.
Success: return to the executing thread.
Failure: will never know. */
if (remcomInBuffer[1] != '\0') {
cris_reg.pc = gdb_cris_strtol (&remcomInBuffer[1], 0, 16);
}
enableDebugIRQ();
return;
case 's':
/* Step. sAA..AA
AA..AA is the address where execution is resumed. If AA..AA is
omitted, resume at the present address. Success: return to the
executing thread. Failure: will never know.
Should never be invoked. The single-step is implemented on
the host side. If ever invoked, it is an internal error E04. */
gdb_cris_strcpy (remcomOutBuffer, error_message[E04]);
putpacket (remcomOutBuffer);
return;
case '?':
/* The last signal which caused a stop. ?
Success: SAA, where AA is the signal number.
Failure: void. */
remcomOutBuffer[0] = 'S';
remcomOutBuffer[1] = hex_asc_hi(sigval);
remcomOutBuffer[2] = hex_asc_lo(sigval);
remcomOutBuffer[3] = 0;
break;
case 'D':
/* Detach from host. D
Success: OK, and return to the executing thread.
Failure: will never know */
putpacket ("OK");
return;
case 'k':
case 'r':
/* kill request or reset request.
Success: restart of target.
Failure: will never know. */
kill_restart ();
break;
case 'C':
case 'S':
case '!':
case 'R':
case 'd':
/* Continue with signal sig. Csig;AA..AA
Step with signal sig. Ssig;AA..AA
Use the extended remote protocol. !
Restart the target system. R0
Toggle debug flag. d
Search backwards. tAA:PP,MM
Not supported: E04 */
gdb_cris_strcpy (remcomOutBuffer, error_message[E04]);
break;
default:
/* The stub should ignore other request and send an empty
response ($#<checksum>). This way we can extend the protocol and GDB
can tell whether the stub it is talking to uses the old or the new. */
remcomOutBuffer[0] = 0;
break;
}
putpacket(remcomOutBuffer);
}
}
/********************************** Breakpoint *******************************/
/* The hook for both a static (compiled) and a dynamic breakpoint set by GDB.
An internal stack is used by the stub. The register image of the caller is
stored in the structure register_image.
Interactive communication with the host is handled by handle_exception and
finally the register image is restored. */
void kgdb_handle_breakpoint(void);
asm ("\n"
" .global kgdb_handle_breakpoint\n"
"kgdb_handle_breakpoint:\n"
";;\n"
";; Response to the break-instruction\n"
";;\n"
";; Create a register image of the caller\n"
";;\n"
" move $dccr,[cris_reg+0x5E] ; Save the flags in DCCR before disable interrupts\n"
" di ; Disable interrupts\n"
" move.d $r0,[cris_reg] ; Save R0\n"
" move.d $r1,[cris_reg+0x04] ; Save R1\n"
" move.d $r2,[cris_reg+0x08] ; Save R2\n"
" move.d $r3,[cris_reg+0x0C] ; Save R3\n"
" move.d $r4,[cris_reg+0x10] ; Save R4\n"
" move.d $r5,[cris_reg+0x14] ; Save R5\n"
" move.d $r6,[cris_reg+0x18] ; Save R6\n"
" move.d $r7,[cris_reg+0x1C] ; Save R7\n"
" move.d $r8,[cris_reg+0x20] ; Save R8\n"
" move.d $r9,[cris_reg+0x24] ; Save R9\n"
" move.d $r10,[cris_reg+0x28] ; Save R10\n"
" move.d $r11,[cris_reg+0x2C] ; Save R11\n"
" move.d $r12,[cris_reg+0x30] ; Save R12\n"
" move.d $r13,[cris_reg+0x34] ; Save R13\n"
" move.d $sp,[cris_reg+0x38] ; Save SP (R14)\n"
";; Due to the old assembler-versions BRP might not be recognized\n"
" .word 0xE670 ; move brp,$r0\n"
" subq 2,$r0 ; Set to address of previous instruction.\n"
" move.d $r0,[cris_reg+0x3c] ; Save the address in PC (R15)\n"
" clear.b [cris_reg+0x40] ; Clear P0\n"
" move $vr,[cris_reg+0x41] ; Save special register P1\n"
" clear.w [cris_reg+0x42] ; Clear P4\n"
" move $ccr,[cris_reg+0x44] ; Save special register CCR\n"
" move $mof,[cris_reg+0x46] ; P7\n"
" clear.d [cris_reg+0x4A] ; Clear P8\n"
" move $ibr,[cris_reg+0x4E] ; P9,\n"
" move $irp,[cris_reg+0x52] ; P10,\n"
" move $srp,[cris_reg+0x56] ; P11,\n"
" move $dtp0,[cris_reg+0x5A] ; P12, register BAR, assembler might not know BAR\n"
" ; P13, register DCCR already saved\n"
";; Due to the old assembler-versions BRP might not be recognized\n"
" .word 0xE670 ; move brp,r0\n"
";; Static (compiled) breakpoints must return to the next instruction in order\n"
";; to avoid infinite loops. Dynamic (gdb-invoked) must restore the instruction\n"
";; in order to execute it when execution is continued.\n"
" test.b [is_dyn_brkp] ; Is this a dynamic breakpoint?\n"
" beq is_static ; No, a static breakpoint\n"
" nop\n"
" subq 2,$r0 ; rerun the instruction the break replaced\n"
"is_static:\n"
" moveq 1,$r1\n"
" move.b $r1,[is_dyn_brkp] ; Set the state variable to dynamic breakpoint\n"
" move.d $r0,[cris_reg+0x62] ; Save the return address in BRP\n"
" move $usp,[cris_reg+0x66] ; USP\n"
";;\n"
";; Handle the communication\n"
";;\n"
" move.d internal_stack+1020,$sp ; Use the internal stack which grows upward\n"
" moveq 5,$r10 ; SIGTRAP\n"
" jsr handle_exception ; Interactive routine\n"
";;\n"
";; Return to the caller\n"
";;\n"
" move.d [cris_reg],$r0 ; Restore R0\n"
" move.d [cris_reg+0x04],$r1 ; Restore R1\n"
" move.d [cris_reg+0x08],$r2 ; Restore R2\n"
" move.d [cris_reg+0x0C],$r3 ; Restore R3\n"
" move.d [cris_reg+0x10],$r4 ; Restore R4\n"
" move.d [cris_reg+0x14],$r5 ; Restore R5\n"
" move.d [cris_reg+0x18],$r6 ; Restore R6\n"
" move.d [cris_reg+0x1C],$r7 ; Restore R7\n"
" move.d [cris_reg+0x20],$r8 ; Restore R8\n"
" move.d [cris_reg+0x24],$r9 ; Restore R9\n"
" move.d [cris_reg+0x28],$r10 ; Restore R10\n"
" move.d [cris_reg+0x2C],$r11 ; Restore R11\n"
" move.d [cris_reg+0x30],$r12 ; Restore R12\n"
" move.d [cris_reg+0x34],$r13 ; Restore R13\n"
";;\n"
";; FIXME: Which registers should be restored?\n"
";;\n"
" move.d [cris_reg+0x38],$sp ; Restore SP (R14)\n"
" move [cris_reg+0x56],$srp ; Restore the subroutine return pointer.\n"
" move [cris_reg+0x5E],$dccr ; Restore DCCR\n"
" move [cris_reg+0x66],$usp ; Restore USP\n"
" jump [cris_reg+0x62] ; A jump to the content in register BRP works.\n"
" nop ;\n"
"\n");
/* The hook for an interrupt generated by GDB. An internal stack is used
by the stub. The register image of the caller is stored in the structure
register_image. Interactive communication with the host is handled by
handle_exception and finally the register image is restored. Due to the
old assembler which does not recognise the break instruction and the
breakpoint return pointer hex-code is used. */
void kgdb_handle_serial(void);
asm ("\n"
" .global kgdb_handle_serial\n"
"kgdb_handle_serial:\n"
";;\n"
";; Response to a serial interrupt\n"
";;\n"
"\n"
" move $dccr,[cris_reg+0x5E] ; Save the flags in DCCR\n"
" di ; Disable interrupts\n"
" move.d $r0,[cris_reg] ; Save R0\n"
" move.d $r1,[cris_reg+0x04] ; Save R1\n"
" move.d $r2,[cris_reg+0x08] ; Save R2\n"
" move.d $r3,[cris_reg+0x0C] ; Save R3\n"
" move.d $r4,[cris_reg+0x10] ; Save R4\n"
" move.d $r5,[cris_reg+0x14] ; Save R5\n"
" move.d $r6,[cris_reg+0x18] ; Save R6\n"
" move.d $r7,[cris_reg+0x1C] ; Save R7\n"
" move.d $r8,[cris_reg+0x20] ; Save R8\n"
" move.d $r9,[cris_reg+0x24] ; Save R9\n"
" move.d $r10,[cris_reg+0x28] ; Save R10\n"
" move.d $r11,[cris_reg+0x2C] ; Save R11\n"
" move.d $r12,[cris_reg+0x30] ; Save R12\n"
" move.d $r13,[cris_reg+0x34] ; Save R13\n"
" move.d $sp,[cris_reg+0x38] ; Save SP (R14)\n"
" move $irp,[cris_reg+0x3c] ; Save the address in PC (R15)\n"
" clear.b [cris_reg+0x40] ; Clear P0\n"
" move $vr,[cris_reg+0x41] ; Save special register P1,\n"
" clear.w [cris_reg+0x42] ; Clear P4\n"
" move $ccr,[cris_reg+0x44] ; Save special register CCR\n"
" move $mof,[cris_reg+0x46] ; P7\n"
" clear.d [cris_reg+0x4A] ; Clear P8\n"
" move $ibr,[cris_reg+0x4E] ; P9,\n"
" move $irp,[cris_reg+0x52] ; P10,\n"
" move $srp,[cris_reg+0x56] ; P11,\n"
" move $dtp0,[cris_reg+0x5A] ; P12, register BAR, assembler might not know BAR\n"
" ; P13, register DCCR already saved\n"
";; Due to the old assembler-versions BRP might not be recognized\n"
" .word 0xE670 ; move brp,r0\n"
" move.d $r0,[cris_reg+0x62] ; Save the return address in BRP\n"
" move $usp,[cris_reg+0x66] ; USP\n"
"\n"
";; get the serial character (from debugport.c) and check if it is a ctrl-c\n"
"\n"
" jsr getDebugChar\n"
" cmp.b 3, $r10\n"
" bne goback\n"
" nop\n"
"\n"
" move.d [cris_reg+0x5E], $r10 ; Get DCCR\n"
" btstq 8, $r10 ; Test the U-flag.\n"
" bmi goback\n"
" nop\n"
"\n"
";;\n"
";; Handle the communication\n"
";;\n"
" move.d internal_stack+1020,$sp ; Use the internal stack\n"
" moveq 2,$r10 ; SIGINT\n"
" jsr handle_exception ; Interactive routine\n"
"\n"
"goback:\n"
";;\n"
";; Return to the caller\n"
";;\n"
" move.d [cris_reg],$r0 ; Restore R0\n"
" move.d [cris_reg+0x04],$r1 ; Restore R1\n"
" move.d [cris_reg+0x08],$r2 ; Restore R2\n"
" move.d [cris_reg+0x0C],$r3 ; Restore R3\n"
" move.d [cris_reg+0x10],$r4 ; Restore R4\n"
" move.d [cris_reg+0x14],$r5 ; Restore R5\n"
" move.d [cris_reg+0x18],$r6 ; Restore R6\n"
" move.d [cris_reg+0x1C],$r7 ; Restore R7\n"
" move.d [cris_reg+0x20],$r8 ; Restore R8\n"
" move.d [cris_reg+0x24],$r9 ; Restore R9\n"
" move.d [cris_reg+0x28],$r10 ; Restore R10\n"
" move.d [cris_reg+0x2C],$r11 ; Restore R11\n"
" move.d [cris_reg+0x30],$r12 ; Restore R12\n"
" move.d [cris_reg+0x34],$r13 ; Restore R13\n"
";;\n"
";; FIXME: Which registers should be restored?\n"
";;\n"
" move.d [cris_reg+0x38],$sp ; Restore SP (R14)\n"
" move [cris_reg+0x56],$srp ; Restore the subroutine return pointer.\n"
" move [cris_reg+0x5E],$dccr ; Restore DCCR\n"
" move [cris_reg+0x66],$usp ; Restore USP\n"
" reti ; Return from the interrupt routine\n"
" nop\n"
"\n");
/* Use this static breakpoint in the start-up only. */
void
breakpoint(void)
{
kgdb_started = 1;
is_dyn_brkp = 0; /* This is a static, not a dynamic breakpoint. */
__asm__ volatile ("break 8"); /* Jump to handle_breakpoint. */
}
/* initialize kgdb. doesn't break into the debugger, but sets up irq and ports */
void
kgdb_init(void)
{
/* could initialize debug port as well but it's done in head.S already... */
/* breakpoint handler is now set in irq.c */
set_int_vector(8, kgdb_handle_serial);
enableDebugIRQ();
}
/****************************** End of file **********************************/
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