diff options
Diffstat (limited to 'arch/cris/arch-v10/kernel/kgdb.c')
| -rw-r--r-- | arch/cris/arch-v10/kernel/kgdb.c | 1568 |
1 files changed, 1568 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/kernel/kgdb.c b/arch/cris/arch-v10/kernel/kgdb.c new file mode 100644 index 00000000000..7d368c877ee --- /dev/null +++ b/arch/cris/arch-v10/kernel/kgdb.c @@ -0,0 +1,1568 @@ +/*!************************************************************************** +*! +*! 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 1.5 2004/10/07 13:59:08 starvik +*! Corrected call to set_int_vector +*! +*! Revision 1.4 2003/04/09 05:20:44 starvik +*! Merge of Linux 2.5.67 +*! +*! Revision 1.3 2003/01/21 19:11:08 starvik +*! Modified include path for new dir layout +*! +*! Revision 1.2 2002/11/19 14:35:24 starvik +*! Changes from linux 2.4 +*! Changed struct initializer syntax to the currently prefered notation +*! +*! Revision 1.1 2001/12/17 13:59:27 bjornw +*! Initial revision +*! +*! Revision 1.6 2001/10/09 13:10:03 matsfg +*! Added $ on registers and removed some underscores +*! +*! Revision 1.5 2001/04/17 13:58:39 orjanf +*! * Renamed CONFIG_KGDB to CONFIG_ETRAX_KGDB. +*! +*! Revision 1.4 2001/02/23 13:45:19 bjornw +*! config.h check +*! +*! Revision 1.3 2001/01/31 18:08:23 orjanf +*! Removed kgdb_handle_breakpoint from being the break 8 handler. +*! +*! 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 1.5 2004/10/07 13:59:08 starvik Exp $ +*! +*! (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 <asm/setup.h> +#include <asm/ptrace.h> + +#include <asm/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; + +/************** 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)); |