cregit-Linux how code gets into the kernel

Release 4.7 arch/cris/arch-v10/kernel/kgdb.c

/*!**************************************************************************
*!
*! 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, E08
};

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",
	"E08 Invalid parameter"
};
/********************************* 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 __used is_dyn_brkp;

/********************************* 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); }

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/* Find length of s[]. */
static int gdb_cris_strlen (const char *s) { const char *sc; for (sc = s; *sc != '\0'; sc++) ; return (sc - s); }

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/* 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); }

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/******************************* 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; }

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/********************************** Packet I/O ******************************/ /* 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); }

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/* 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); }

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/* 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_to_bin(getDebugChar()) << 4; xmitcsum += hex_to_bin(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); }

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/* 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() != '+')); }

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/* 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); }

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/********************************* Register image ****************************/ /* Write a value to a specified register in the register image of the current thread. Returns status code SUCCESS, E02, E05 or E08. */
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. */ if (hex2bin((unsigned char *)current_reg + regno * sizeof(unsigned int), val, sizeof(unsigned int))) status = E08; } 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. */ if (hex2bin((unsigned char *)&(current_reg->ccr) + (regno-CCR) * sizeof(unsigned short), val, sizeof(unsigned short))) status = E08; } else if (regno >= MOF && regno <= USP) { /* 32 bit register with complex offset. (P8 has been taken care of.) */ if (hex2bin((unsigned char *)&(current_reg->ibr) + (regno-IBR) * sizeof(unsigned int), val, sizeof(unsigned int))) status = E08; } else { /* Do not support nonexisting or unimplemented registers (P2, P3, and P6). */ status = E05; } return status; }

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/* 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; } }

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/********************************** 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); }

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/* Performs a complete re-start from scratch. */
static void kill_restart (void) { machine_restart(""); }

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Total13100.00%1100.00%

/* 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: E08. */ if (hex2bin((char *)&cris_reg, &remcomInBuffer[1], sizeof(registers))) gdb_cris_strcpy (remcomOutBuffer, error_message[E08]); else 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, E08 */ { 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; case E08: /* Invalid parameter. */ gdb_cris_strcpy (remcomOutBuffer, error_message[E08]); 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: E08. */ { 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') { if (hex2bin(addr, dataptr + 1, length)) gdb_cris_strcpy (remcomOutBuffer, error_message[E08]); else gdb_cris_strcpy (remcomOutBuffer, "OK"); } 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); } }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds53389.88%120.00%
andy shevchenkoandy shevchenko549.11%120.00%
geert uytterhoevengeert uytterhoeven40.67%240.00%
harvey harrisonharvey harrison20.34%120.00%
Total593100.00%5100.00%

/********************************** 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 $bar,[cris_reg+0x5A] ; P12,\n" " ; P13, register DCCR already saved\n" ";; Due to the old assembler-versions BRP might not be recognized\n" " .word 0xE670 ; move brp,r0\n" ";; Static (compiled) breakpoints must return to the next instruction in order\n" ";; to avoid infinite loops. Dynamic (gdb-invoked) must restore the instruction\n" ";; in order to execute it when execution is continued.\n" " test.b [is_dyn_brkp] ; Is this a dynamic breakpoint?\n" " beq is_static ; No, a static breakpoint\n" " nop\n" " subq 2,$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 $bar,[cris_reg+0x5A] ; P12,\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. */ }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds20100.00%1100.00%
Total20100.00%1100.00%

/* 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(); }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds19100.00%2100.00%
Total19100.00%2100.00%

/****************************** End of file **********************************/

Overall Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds165462.34%211.76%
geert uytterhoevengeert uytterhoeven89633.77%423.53%
andy shevchenkoandy shevchenko843.17%211.76%
harvey harrisonharvey harrison60.23%15.88%
gang chengang chen30.11%211.76%
mikael starvikmikael starvik30.11%15.88%
wanlong gaowanlong gao30.11%15.88%
jesper nilssonjesper nilsson20.08%211.76%
steven colesteven cole10.04%15.88%
jean delvarejean delvare10.04%15.88%
Total2653100.00%17100.00%
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