patch-2.4.2 linux/arch/cris/kernel/kgdb.c
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- Lines: 1541
- Date:
Thu Feb 8 16:32:44 2001
- Orig file:
v2.4.1/linux/arch/cris/kernel/kgdb.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.1/linux/arch/cris/kernel/kgdb.c linux/arch/cris/kernel/kgdb.c
@@ -0,0 +1,1540 @@
+/*!**************************************************************************
+*!
+*! 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
+*!
+*! $Log: kgdb.c,v $
+*! Revision 1.2 2001/01/12 14:22:25 orjanf
+*! Updated kernel debugging support to work with ETRAX 100LX.
+*!
+*! Revision 1.1 2000/07/10 16:25:21 bjornw
+*! Initial revision
+*!
+*! Revision 1.1.1.1 1999/12/03 14:57:31 bjornw
+*! * Initial version of arch/cris, the latest CRIS architecture with an MMU.
+*! Mostly copied from arch/etrax100 with appropriate renames of files.
+*! The mm/ subdir is copied from arch/i386.
+*! This does not compile yet at all.
+*!
+*!
+*! Revision 1.4 1999/07/22 17:25:25 bjornw
+*! Dont wait for + in putpacket if we havent hit the initial breakpoint yet. Added a kgdb_init function which sets up the break and irq vectors.
+*!
+*! Revision 1.3 1999/07/21 19:51:18 bjornw
+*! Check if the interrupting char is a ctrl-C, ignore otherwise.
+*!
+*! Revision 1.2 1999/07/21 18:09:39 bjornw
+*! Ported to eLinux architecture, and added some kgdb documentation.
+*!
+*!
+*!---------------------------------------------------------------------------
+*!
+*! $Id: kgdb.c,v 1.2 2001/01/12 14:22:25 orjanf Exp $
+*!
+*! (C) Copyright 1999, Axis Communications AB, LUND, SWEDEN
+*!
+*!**************************************************************************/
+/* @(#) cris_stub.c 1.3 06/17/99 */
+
+/*
+ * kgdb usage notes:
+ * -----------------
+ *
+ * If you select CONFIG_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. accesing 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 <asm/setup.h>
+#include <asm/ptrace.h>
+
+#include <asm/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;
+
+/************** Prototypes for local library functions ***********************/
+
+/* Copy of strcpy from libc. */
+static char *gdb_cris_strcpy (char *s1, const char *s2);
+
+/* Copy of strlen from libc. */
+static int gdb_cris_strlen (const char *s);
+
+/* Copy of memchr from libc. */
+static void *gdb_cris_memchr (const void *s, int c, int n);
+
+/* Copy of strtol from libc. Does only support base 16. */
+static int gdb_cris_strtol (const char *s, char **endptr, int base);
+
+/********************** Prototypes for local functions. **********************/
+/* Copy the content of a register image into another. The size n is
+ the size of the register image. Due to struct assignment generation of
+ memcpy in libc. */
+static void copy_registers (registers *dptr, registers *sptr, int n);
+
+/* Copy the stored registers from the stack. Put the register contents
+ of thread thread_id in the struct reg. */
+static void copy_registers_from_stack (int thread_id, registers *reg);
+
+/* Copy the registers to the stack. Put the register contents of thread
+ thread_id from struct reg to the stack. */
+static void copy_registers_to_stack (int thread_id, registers *reg);
+
+/* Write a value to a specified register regno in the register image
+ of the current thread. */
+static int write_register (int regno, char *val);
+
+/* Write a value to a specified register in the stack of a thread other
+ than the current thread. */
+static write_stack_register (int thread_id, int regno, char *valptr);
+
+/* Read a value from a specified register in the register image. Returns the
+ status of the read operation. The register value is returned in valptr. */
+static int read_register (char regno, unsigned int *valptr);
+
+/* 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);
+
+/* Returns the character equivalent of a nibble, bit 7, 6, 5, and 4 of a byte,
+ represented by int x. */
+static char highhex (int x);
+
+/* Returns the character equivalent of a nibble, bit 3, 2, 1, and 0 of a byte,
+ represented by int x. */
+static char lowhex (int x);
+
+/* Returns the integer equivalent of a hexadecimal character. */
+static int hex (char ch);
+
+/* 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);
+
+/* 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);
+
+/* 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. */
+static unsigned char *bin2mem (unsigned char *mem, unsigned char *buf, int count);
+
+/* Await the sequence $<data>#<checksum> and store <data> in the array buffer
+ returned. */
+static void getpacket (char *buffer);
+
+/* Send $<data>#<checksum> from the <data> in the array buffer. */
+static void putpacket (char *buffer);
+
+/* Build and send a response packet in order to inform the host the
+ stub is stopped. */
+static void stub_is_stopped (int sigval);
+
+/* All expected commands are sent from remote.c. Send a response according
+ to the description in remote.c. */
+static void handle_exception (int sigval);
+
+/* Performs a complete re-start from scratch. ETRAX specific. */
+static void kill_restart (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
+
+/* Avoid warning as the internal_stack is not used in the C-code. */
+#define USEDVAR(name) { if (name) { ; } }
+#define USEDFUN(name) { void (*pf)(void) = (void *)name; USEDVAR(pf) }
+
+/********************************** 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
+
+/* Definition of all valid hexadecimal characters */
+static const char hexchars[] = "0123456789abcdef";
+
+/* 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. */
+static registers 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 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'.
+*/
+
+/* Need two task id pointers in order to handle Hct and Hgt commands. */
+static int current_thread_c = 0;
+static int current_thread_g = 0;
+
+/* Need two register images in order to handle Hct and Hgt commands. The
+ variable reg_g is in addition to reg above. */
+static registers reg_g;
+
+/********************************** Breakpoint *******************************/
+/* Use an internal stack in the breakpoint and interrupt response routines */
+#define INTERNAL_STACK_SIZE 1024
+static 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(hexchars, *s1, base)) != NULL; ++s1)
+ x = x * base + (sd - hexchars);
+
+ if (endptr)
+ {
+ /* Unconverted suffix is stored in endptr unless endptr is NULL. */
+ *endptr = s1;
+ }
+
+ return x;
+}
+
+int
+double_this(int x)
+{
+ return 2 * x;
+}
+
+/********************************* Register image ****************************/
+/* Copy the content of a register image into another. The size n is
+ the size of the register image. Due to struct assignment generation of
+ memcpy in libc. */
+static void
+copy_registers (registers *dptr, registers *sptr, int n)
+{
+ unsigned char *dreg;
+ unsigned char *sreg;
+
+ for (dreg = (unsigned char*)dptr, sreg = (unsigned char*)sptr; n > 0; n--)
+ *dreg++ = *sreg++;
+}
+
+#ifdef PROCESS_SUPPORT
+/* Copy the stored registers from the stack. Put the register contents
+ of thread thread_id in the struct reg. */
+static void
+copy_registers_from_stack (int thread_id, registers *regptr)
+{
+ int j;
+ stack_registers *s = (stack_registers *)stack_list[thread_id];
+ unsigned int *d = (unsigned int *)regptr;
+
+ for (j = 13; j >= 0; j--)
+ *d++ = s->r[j];
+ regptr->sp = (unsigned int)stack_list[thread_id];
+ regptr->pc = s->pc;
+ regptr->dccr = s->dccr;
+ regptr->srp = s->srp;
+}
+
+/* Copy the registers to the stack. Put the register contents of thread
+ thread_id from struct reg to the stack. */
+static void
+copy_registers_to_stack (int thread_id, registers *regptr)
+{
+ int i;
+ stack_registers *d = (stack_registers *)stack_list[thread_id];
+ unsigned int *s = (unsigned int *)regptr;
+
+ for (i = 0; i < 14; i++) {
+ d->r[i] = *s++;
+ }
+ d->pc = regptr->pc;
+ d->dccr = regptr->dccr;
+ d->srp = regptr->srp;
+}
+#endif
+
+/* 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 = ®
+
+ 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;
+}
+
+#ifdef PROCESS_SUPPORT
+/* Write a value to a specified register in the stack of a thread other
+ than the current thread. Returns status code SUCCESS or E07. */
+static int
+write_stack_register (int thread_id, int regno, char *valptr)
+{
+ int status = SUCCESS;
+ stack_registers *d = (stack_registers *)stack_list[thread_id];
+ unsigned int val;
+
+ hex2mem ((unsigned char *)&val, valptr, sizeof(unsigned int));
+ if (regno >= R0 && regno < SP) {
+ d->r[regno] = val;
+ }
+ else if (regno == SP) {
+ stack_list[thread_id] = val;
+ }
+ else if (regno == PC) {
+ d->pc = val;
+ }
+ else if (regno == SRP) {
+ d->srp = val;
+ }
+ else if (regno == DCCR) {
+ d->dccr = val;
+ }
+ else {
+ /* Do not support registers in the current thread. */
+ status = E07;
+ }
+ return status;
+}
+#endif
+
+/* 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 = ®
+
+ 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;
+ }
+}
+
+/********************************** Packet I/O ******************************/
+/* Returns the character equivalent of a nibble, bit 7, 6, 5, and 4 of a byte,
+ represented by int x. */
+static inline char
+highhex(int x)
+{
+ return hexchars[(x >> 4) & 0xf];
+}
+
+/* Returns the character equivalent of a nibble, bit 3, 2, 1, and 0 of a byte,
+ represented by int x. */
+static inline char
+lowhex(int x)
+{
+ return hexchars[x & 0xf];
+}
+
+/* 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 int do_printk = 0;
+
+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++ = highhex (ch);
+ *buf++ = lowhex (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) {
+ 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 (highhex (checksum));
+ putDebugChar (lowhex (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);
+}
+
+/********************************** 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++ = highhex (sigval);
+ *ptr++ = lowhex (sigval);
+
+ /* Send register contents. We probably only need to send the
+ * PC, frame pointer and stack pointer here. Other registers will be
+ * explicitely 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, ®_cont);
+
+ if (status == SUCCESS) {
+
+ *ptr++ = highhex (regno);
+ *ptr++ = lowhex (regno);
+ *ptr++ = ':';
+
+ ptr = mem2hex(ptr, (unsigned char *)®_cont,
+ register_size[regno]);
+ *ptr++ = ';';
+ }
+
+ }
+
+#ifdef PROCESS_SUPPORT
+ /* Store the registers of the executing thread. Assume that both step,
+ continue, and register content requests are with respect to this
+ thread. The executing task is from the operating system scheduler. */
+
+ current_thread_c = executing_task;
+ current_thread_g = executing_task;
+
+ /* A struct assignment translates into a libc memcpy call. Avoid
+ all libc functions in order to prevent recursive break points. */
+ copy_registers (®_g, ®, sizeof(registers));
+
+ /* Store thread:r...; with the executing task TID. */
+ gdb_cris_strcpy (&remcomOutBuffer[pos], "thread:");
+ pos += gdb_cris_strlen ("thread:");
+ remcomOutBuffer[pos++] = highhex (executing_task);
+ remcomOutBuffer[pos++] = lowhex (executing_task);
+ gdb_cris_strcpy (&remcomOutBuffer[pos], ";");
+#endif
+
+ /* null-terminate and send it off */
+
+ *ptr = 0;
+
+ putpacket (remcomOutBuffer);
+}
+
+/* All expected commands are sent from remote.c. Send a response according
+ to the description in remote.c. */
+static void
+handle_exception (int sigval)
+{
+ /* Avoid warning of not used. */
+
+ USEDFUN(handle_exception);
+ USEDVAR(internal_stack[0]);
+
+ /* 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. */
+
+ {
+#ifdef PROCESS_SUPPORT
+ /* Use the special register content in the executing thread. */
+ copy_registers (®_g, ®, sizeof(registers));
+ /* Replace the content available on the stack. */
+ if (current_thread_g != executing_task) {
+ copy_registers_from_stack (current_thread_g, ®_g);
+ }
+ mem2hex ((unsigned char *)remcomOutBuffer, (unsigned char *)®_g, sizeof(registers));
+#else
+ mem2hex(remcomOutBuffer, (char *)®, sizeof(registers));
+#endif
+ }
+ break;
+
+ case 'G':
+ /* Write registers. GXX..XX
+ Each byte of register data is described by two hex digits.
+ Success: OK
+ Failure: void. */
+#ifdef PROCESS_SUPPORT
+ hex2mem ((unsigned char *)®_g, &remcomInBuffer[1], sizeof(registers));
+ if (current_thread_g == executing_task) {
+ copy_registers (®, ®_g, sizeof(registers));
+ }
+ else {
+ copy_registers_to_stack(current_thread_g, ®_g);
+ }
+#else
+ hex2mem((char *)®, &remcomInBuffer[1], sizeof(registers));
+#endif
+ 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;
+#ifdef PROCESS_SUPPORT
+ if (current_thread_g =! executing_task)
+ status = write_stack_register (current_thread_g, regno, suffix+1);
+ else
+#endif
+ 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') {
+ 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] = highhex (sigval);
+ remcomOutBuffer[2] = lowhex (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;
+#ifdef PROCESS_SUPPORT
+
+ case 'T':
+ /* Thread alive. TXX
+ Is thread XX alive?
+ Success: OK, thread XX is alive.
+ Failure: E03, thread XX is dead. */
+ {
+ int thread_id = (int)gdb_cris_strtol (&remcomInBuffer[1], 0, 16);
+ /* Cannot tell whether it is alive or not. */
+ if (thread_id >= 0 && thread_id < number_of_tasks)
+ gdb_cris_strcpy (remcomOutBuffer, "OK");
+ }
+ break;
+
+ case 'H':
+ /* Set thread for subsequent operations: Hct
+ c = 'c' for thread used in step and continue;
+ t can be -1 for all threads.
+ c = 'g' for thread used in other operations.
+ t = 0 means pick any thread.
+ Success: OK
+ Failure: E01 */
+ {
+ int thread_id = gdb_cris_strtol (&remcomInBuffer[2], 0, 16);
+ if (remcomInBuffer[1] == 'c') {
+ /* c = 'c' for thread used in step and continue */
+ /* Do not change current_thread_c here. It would create a mess in
+ the scheduler. */
+ gdb_cris_strcpy (remcomOutBuffer, "OK");
+ }
+ else if (remcomInBuffer[1] == 'g') {
+ /* c = 'g' for thread used in other operations.
+ t = 0 means pick any thread. Impossible since the scheduler does
+ not allow that. */
+ if (thread_id >= 0 && thread_id < number_of_tasks) {
+ current_thread_g = thread_id;
+ gdb_cris_strcpy (remcomOutBuffer, "OK");
+ }
+ else {
+ /* Not expected - send an error message. */
+ gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
+ }
+ }
+ else {
+ /* Not expected - send an error message. */
+ gdb_cris_strcpy (remcomOutBuffer, error_message[E01]);
+ }
+ }
+ break;
+
+ case 'q':
+ case 'Q':
+ /* Query of general interest. qXXXX
+ Set general value XXXX. QXXXX=yyyy */
+ {
+ int pos;
+ int nextpos;
+ int thread_id;
+
+ switch (remcomInBuffer[1]) {
+ case 'C':
+ /* Identify the remote current thread. */
+ gdb_cris_strcpy (&remcomOutBuffer[0], "QC");
+ remcomOutBuffer[2] = highhex (current_thread_c);
+ remcomOutBuffer[3] = lowhex (current_thread_c);
+ remcomOutBuffer[4] = '\0';
+ break;
+ case 'L':
+ gdb_cris_strcpy (&remcomOutBuffer[0], "QM");
+ /* Reply with number of threads. */
+ if (os_is_started()) {
+ remcomOutBuffer[2] = highhex (number_of_tasks);
+ remcomOutBuffer[3] = lowhex (number_of_tasks);
+ }
+ else {
+ remcomOutBuffer[2] = highhex (0);
+ remcomOutBuffer[3] = lowhex (1);
+ }
+ /* Done with the reply. */
+ remcomOutBuffer[4] = lowhex (1);
+ pos = 5;
+ /* Expects the argument thread id. */
+ for (; pos < (5 + HEXCHARS_IN_THREAD_ID); pos++)
+ remcomOutBuffer[pos] = remcomInBuffer[pos];
+ /* Reply with the thread identifiers. */
+ if (os_is_started()) {
+ /* Store the thread identifiers of all tasks. */
+ for (thread_id = 0; thread_id < number_of_tasks; thread_id++) {
+ nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
+ for (; pos < nextpos; pos ++)
+ remcomOutBuffer[pos] = lowhex (0);
+ remcomOutBuffer[pos++] = lowhex (thread_id);
+ }
+ }
+ else {
+ /* Store the thread identifier of the boot task. */
+ nextpos = pos + HEXCHARS_IN_THREAD_ID - 1;
+ for (; pos < nextpos; pos ++)
+ remcomOutBuffer[pos] = lowhex (0);
+ remcomOutBuffer[pos++] = lowhex (current_thread_c);
+ }
+ remcomOutBuffer[pos] = '\0';
+ break;
+ default:
+ /* Not supported: "" */
+ /* Request information about section offsets: qOffsets. */
+ remcomOutBuffer[0] = 0;
+ break;
+ }
+ }
+ break;
+#endif /* PROCESS_SUPPORT */
+
+ 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);
+ }
+}
+
+/* The jump is to the address 0x00000002. Performs a complete re-start
+ from scratch. */
+static void
+kill_restart ()
+{
+ __asm__ volatile ("jump 2");
+}
+
+/********************************** 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 ("
+ .global _kgdb_handle_breakpoint
+_kgdb_handle_breakpoint:
+;;
+;; Response to the break-instruction
+;;
+;; Create a register image of the caller
+;;
+ move dccr,[_reg+0x5E] ; Save the flags in DCCR before disable interrupts
+ di ; Disable interrupts
+ move.d r0,[_reg] ; Save R0
+ move.d r1,[_reg+0x04] ; Save R1
+ move.d r2,[_reg+0x08] ; Save R2
+ move.d r3,[_reg+0x0C] ; Save R3
+ move.d r4,[_reg+0x10] ; Save R4
+ move.d r5,[_reg+0x14] ; Save R5
+ move.d r6,[_reg+0x18] ; Save R6
+ move.d r7,[_reg+0x1C] ; Save R7
+ move.d r8,[_reg+0x20] ; Save R8
+ move.d r9,[_reg+0x24] ; Save R9
+ move.d r10,[_reg+0x28] ; Save R10
+ move.d r11,[_reg+0x2C] ; Save R11
+ move.d r12,[_reg+0x30] ; Save R12
+ move.d r13,[_reg+0x34] ; Save R13
+ move.d sp,[_reg+0x38] ; Save SP (R14)
+;; Due to the old assembler-versions BRP might not be recognized
+ .word 0xE670 ; move brp,r0
+ subq 2,r0 ; Set to address of previous instruction.
+ move.d r0,[_reg+0x3c] ; Save the address in PC (R15)
+ clear.b [_reg+0x40] ; Clear P0
+ move vr,[_reg+0x41] ; Save special register P1
+ clear.w [_reg+0x42] ; Clear P4
+ move ccr,[_reg+0x44] ; Save special register CCR
+ move mof,[_reg+0x46] ; P7
+ clear.d [_reg+0x4A] ; Clear P8
+ move ibr,[_reg+0x4E] ; P9,
+ move irp,[_reg+0x52] ; P10,
+ move srp,[_reg+0x56] ; P11,
+ move dtp0,[_reg+0x5A] ; P12, register BAR, assembler might not know BAR
+ ; P13, register DCCR already saved
+;; Due to the old assembler-versions BRP might not be recognized
+ .word 0xE670 ; move brp,r0
+;; Static (compiled) breakpoints must return to the next instruction in order
+;; to avoid infinite loops. Dynamic (gdb-invoked) must restore the instruction
+;; in order to execute it when execution is continued.
+ test.b [_is_dyn_brkp] ; Is this a dynamic breakpoint?
+ beq is_static ; No, a static breakpoint
+ nop
+ subq 2,r0 ; rerun the instruction the break replaced
+is_static:
+ moveq 1,r1
+ move.b r1,[_is_dyn_brkp] ; Set the state variable to dynamic breakpoint
+ move.d r0,[_reg+0x62] ; Save the return address in BRP
+ move usp,[_reg+0x66] ; USP
+;;
+;; Handle the communication
+;;
+ move.d _internal_stack+1020,sp ; Use the internal stack which grows upward
+ moveq 5,r10 ; SIGTRAP
+ jsr _handle_exception ; Interactive routine
+;;
+;; Return to the caller
+;;
+ move.d [_reg],r0 ; Restore R0
+ move.d [_reg+0x04],r1 ; Restore R1
+ move.d [_reg+0x08],r2 ; Restore R2
+ move.d [_reg+0x0C],r3 ; Restore R3
+ move.d [_reg+0x10],r4 ; Restore R4
+ move.d [_reg+0x14],r5 ; Restore R5
+ move.d [_reg+0x18],r6 ; Restore R6
+ move.d [_reg+0x1C],r7 ; Restore R7
+ move.d [_reg+0x20],r8 ; Restore R8
+ move.d [_reg+0x24],r9 ; Restore R9
+ move.d [_reg+0x28],r10 ; Restore R10
+ move.d [_reg+0x2C],r11 ; Restore R11
+ move.d [_reg+0x30],r12 ; Restore R12
+ move.d [_reg+0x34],r13 ; Restore R13
+;;
+;; FIXME: Which registers should be restored?
+;;
+ move.d [_reg+0x38],sp ; Restore SP (R14)
+ move [_reg+0x56],srp ; Restore the subroutine return pointer.
+ move [_reg+0x5E],dccr ; Restore DCCR
+ move [_reg+0x66],usp ; Restore USP
+ jump [_reg+0x62] ; A jump to the content in register BRP works.
+ nop ;
+");
+
+/* 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 ("
+ .global _kgdb_handle_serial
+_kgdb_handle_serial:
+;;
+;; Response to a serial interrupt
+;;
+
+ move dccr,[_reg+0x5E] ; Save the flags in DCCR
+ di ; Disable interrupts
+ move.d r0,[_reg] ; Save R0
+ move.d r1,[_reg+0x04] ; Save R1
+ move.d r2,[_reg+0x08] ; Save R2
+ move.d r3,[_reg+0x0C] ; Save R3
+ move.d r4,[_reg+0x10] ; Save R4
+ move.d r5,[_reg+0x14] ; Save R5
+ move.d r6,[_reg+0x18] ; Save R6
+ move.d r7,[_reg+0x1C] ; Save R7
+ move.d r8,[_reg+0x20] ; Save R8
+ move.d r9,[_reg+0x24] ; Save R9
+ move.d r10,[_reg+0x28] ; Save R10
+ move.d r11,[_reg+0x2C] ; Save R11
+ move.d r12,[_reg+0x30] ; Save R12
+ move.d r13,[_reg+0x34] ; Save R13
+ move.d sp,[_reg+0x38] ; Save SP (R14)
+ move irp,[_reg+0x3c] ; Save the address in PC (R15)
+ clear.b [_reg+0x40] ; Clear P0
+ move vr,[_reg+0x41] ; Save special register P1,
+ clear.w [_reg+0x42] ; Clear P4
+ move ccr,[_reg+0x44] ; Save special register CCR
+ move mof,[_reg+0x46] ; P7
+ clear.d [_reg+0x4A] ; Clear P8
+ move ibr,[_reg+0x4E] ; P9,
+ move irp,[_reg+0x52] ; P10,
+ move srp,[_reg+0x56] ; P11,
+ move dtp0,[_reg+0x5A] ; P12, register BAR, assembler might not know BAR
+ ; P13, register DCCR already saved
+;; Due to the old assembler-versions BRP might not be recognized
+ .word 0xE670 ; move brp,r0
+ move.d r0,[_reg+0x62] ; Save the return address in BRP
+ move usp,[_reg+0x66] ; USP
+
+;; get the serial character (from debugport.c) and check if its a ctrl-c
+
+ jsr _getDebugChar
+ cmp.b 3, r10
+ bne goback
+ nop
+
+;;
+;; Handle the communication
+;;
+ move.d _internal_stack+1020,sp ; Use the internal stack
+ moveq 2,r10 ; SIGINT
+ jsr _handle_exception ; Interactive routine
+
+goback:
+;;
+;; Return to the caller
+;;
+ move.d [_reg],r0 ; Restore R0
+ move.d [_reg+0x04],r1 ; Restore R1
+ move.d [_reg+0x08],r2 ; Restore R2
+ move.d [_reg+0x0C],r3 ; Restore R3
+ move.d [_reg+0x10],r4 ; Restore R4
+ move.d [_reg+0x14],r5 ; Restore R5
+ move.d [_reg+0x18],r6 ; Restore R6
+ move.d [_reg+0x1C],r7 ; Restore R7
+ move.d [_reg+0x20],r8 ; Restore R8
+ move.d [_reg+0x24],r9 ; Restore R9
+ move.d [_reg+0x28],r10 ; Restore R10
+ move.d [_reg+0x2C],r11 ; Restore R11
+ move.d [_reg+0x30],r12 ; Restore R12
+ move.d [_reg+0x34],r13 ; Restore R13
+;;
+;; FIXME: Which registers should be restored?
+;;
+ move.d [_reg+0x38],sp ; Restore SP (R14)
+ move [_reg+0x56],srp ; Restore the subroutine return pointer.
+ move [_reg+0x5E],dccr ; Restore DCCR
+ move [_reg+0x66],usp ; Restore USP
+ reti ; Return from the interrupt routine
+ nop
+");
+
+/* 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... */
+
+ set_break_vector(8, kgdb_handle_breakpoint);
+ set_int_vector(8, kgdb_handle_serial, 0);
+
+ enableDebugIRQ();
+}
+
+/****************************** End of file **********************************/
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)