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Diffstat (limited to 'arch/cris/arch-v32/kernel/kgdb.c')
| -rw-r--r-- | arch/cris/arch-v32/kernel/kgdb.c | 1660 |
1 files changed, 1660 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/kernel/kgdb.c b/arch/cris/arch-v32/kernel/kgdb.c new file mode 100644 index 00000000000..480e56348be --- /dev/null +++ b/arch/cris/arch-v32/kernel/kgdb.c @@ -0,0 +1,1660 @@ +/* + * arch/cris/arch-v32/kernel/kgdb.c + * + * CRIS v32 version by Orjan Friberg, Axis Communications AB. + * + * S390 version + * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), + * + * Originally written by Glenn Engel, Lake Stevens Instrument Division + * + * Contributed by HP Systems + * + * Modified for SPARC by Stu Grossman, Cygnus Support. + * + * Modified for Linux/MIPS (and MIPS in general) by Andreas Busse + * Send complaints, suggestions etc. to <andy@waldorf-gmbh.de> + * + * Copyright (C) 1995 Andreas Busse + */ + +/* FIXME: Check the documentation. */ + +/* + * 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 <asm/irq.h> +#include <asm/arch/hwregs/reg_map.h> +#include <asm/arch/hwregs/reg_rdwr.h> +#include <asm/arch/hwregs/intr_vect_defs.h> +#include <asm/arch/hwregs/ser_defs.h> + +/* From entry.S. */ +extern void gdb_handle_exception(void); +/* From kgdb_asm.S. */ +extern void kgdb_handle_exception(void); + +static int kgdb_started = 0; + +/********************************* Register image ****************************/ + +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 (if any) */ + unsigned int r9; /* 0x24 */ + unsigned int r10; /* 0x28 */ + unsigned int r11; /* 0x2C */ + unsigned int r12; /* 0x30 */ + unsigned int r13; /* 0x34 */ + unsigned int sp; /* 0x38; R14, Stack pointer */ + unsigned int acr; /* 0x3C; R15, Address calculation register. */ + + unsigned char bz; /* 0x40; P0, 8-bit zero register */ + unsigned char vr; /* 0x41; P1, Version register (8-bit) */ + unsigned int pid; /* 0x42; P2, Process ID */ + unsigned char srs; /* 0x46; P3, Support register select (8-bit) */ + unsigned short wz; /* 0x47; P4, 16-bit zero register */ + unsigned int exs; /* 0x49; P5, Exception status */ + unsigned int eda; /* 0x4D; P6, Exception data address */ + unsigned int mof; /* 0x51; P7, Multiply overflow register */ + unsigned int dz; /* 0x55; P8, 32-bit zero register */ + unsigned int ebp; /* 0x59; P9, Exception base pointer */ + unsigned int erp; /* 0x5D; P10, Exception return pointer. Contains the PC we are interested in. */ + unsigned int srp; /* 0x61; P11, Subroutine return pointer */ + unsigned int nrp; /* 0x65; P12, NMI return pointer */ + unsigned int ccs; /* 0x69; P13, Condition code stack */ + unsigned int usp; /* 0x6D; P14, User mode stack pointer */ + unsigned int spc; /* 0x71; P15, Single step PC */ + unsigned int pc; /* 0x75; Pseudo register (for the most part set to ERP). */ + +} registers; + +typedef +struct bp_register_image +{ + /* Support register bank 0. */ + unsigned int s0_0; + unsigned int s1_0; + unsigned int s2_0; + unsigned int s3_0; + unsigned int s4_0; + unsigned int s5_0; + unsigned int s6_0; + unsigned int s7_0; + unsigned int s8_0; + unsigned int s9_0; + unsigned int s10_0; + unsigned int s11_0; + unsigned int s12_0; + unsigned int s13_0; + unsigned int s14_0; + unsigned int s15_0; + + /* Support register bank 1. */ + unsigned int s0_1; + unsigned int s1_1; + unsigned int s2_1; + unsigned int s3_1; + unsigned int s4_1; + unsigned int s5_1; + unsigned int s6_1; + unsigned int s7_1; + unsigned int s8_1; + unsigned int s9_1; + unsigned int s10_1; + unsigned int s11_1; + unsigned int s12_1; + unsigned int s13_1; + unsigned int s14_1; + unsigned int s15_1; + + /* Support register bank 2. */ + unsigned int s0_2; + unsigned int s1_2; + unsigned int s2_2; + unsigned int s3_2; + unsigned int s4_2; + unsigned int s5_2; + unsigned int s6_2; + unsigned int s7_2; + unsigned int s8_2; + unsigned int s9_2; + unsigned int s10_2; + unsigned int s11_2; + unsigned int s12_2; + unsigned int s13_2; + unsigned int s14_2; + unsigned int s15_2; + + /* Support register bank 3. */ + unsigned int s0_3; /* BP_CTRL */ + unsigned int s1_3; /* BP_I0_START */ + unsigned int s2_3; /* BP_I0_END */ + unsigned int s3_3; /* BP_D0_START */ + unsigned int s4_3; /* BP_D0_END */ + unsigned int s5_3; /* BP_D1_START */ + unsigned int s6_3; /* BP_D1_END */ + unsigned int s7_3; /* BP_D2_START */ + unsigned int s8_3; /* BP_D2_END */ + unsigned int s9_3; /* BP_D3_START */ + unsigned int s10_3; /* BP_D3_END */ + unsigned int s11_3; /* BP_D4_START */ + unsigned int s12_3; /* BP_D4_END */ + unsigned int s13_3; /* BP_D5_START */ + unsigned int s14_3; /* BP_D5_END */ + unsigned int s15_3; /* BP_RESERVED */ + +} support_registers; + +enum register_name +{ + R0, R1, R2, R3, + R4, R5, R6, R7, + R8, R9, R10, R11, + R12, R13, SP, ACR, + + BZ, VR, PID, SRS, + WZ, EXS, EDA, MOF, + DZ, EBP, ERP, SRP, + NRP, CCS, USP, SPC, + PC, + + S0, S1, S2, S3, + S4, S5, S6, S7, + S8, S9, S10, S11, + S12, S13, S14, S15 + +}; + +/* 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, 4, 1, + 2, 4, 4, 4, + 4, 4, 4, 4, + 4, 4, 4, 4, + + 4, + + 4, 4, 4, 4, + 4, 4, 4, 4, + 4, 4, 4, 4, + 4, 4, 4 + +}; + +/* Contains the register image of the kernel. + (Global so that they can be reached from assembler code.) */ +registers reg; +support_registers sreg; + +/************** 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. **********************/ + +/* Write a value to a specified register regno in the register image + of the current thread. */ +static int write_register(int regno, char *val); + +/* 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); + +#ifdef CONFIG_ETRAXFS_SIM +int getDebugChar(void) +{ + return socketread(); +} +#endif + +/* Serial port, writes one character. ETRAX 100 specific. from debugport.c */ +void putDebugChar(int val); + +#ifdef CONFIG_ETRAXFS_SIM +void putDebugChar(int val) +{ + socketwrite((char *)&val, 1); +} +#endif + +/* 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. Not static since it needs to be reached + from assembler code. */ +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 len); + +/* A static breakpoint to be used at startup. */ +void breakpoint(void); + +/* 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 */ +/* FIXME: How do we know it's enough? */ +#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 input_buffer[BUFMAX]; +static char output_buffer[BUFMAX]; + +/* Error and warning messages. */ +enum error_type +{ + SUCCESS, E01, E02, E03, E04, E05, E06, +}; + +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.", +}; + +/********************************** Breakpoint *******************************/ +/* Use an internal stack in the breakpoint and interrupt response routines. + FIXME: How do we know the size of this stack is enough? + Global so it can be reached from assembler code. */ +#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 + ERP as it is whereas a dynamic breakpoint requires subtraction with 2 + in order to execute the instruction. The first breakpoint is static; all + following are assumed to be dynamic. */ +static int dynamic_bp = 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; +} + +/********************************* Register image ****************************/ + +/* Write a value to a specified register in the register image of the current + thread. Returns status code SUCCESS, E02 or E05. */ +static int +write_register(int regno, char *val) +{ + int status = SUCCESS; + + if (regno >= R0 && regno <= ACR) { + /* Consecutive 32-bit registers. */ + hex2mem((unsigned char *)®.r0 + (regno - R0) * sizeof(unsigned int), + val, sizeof(unsigned int)); + + } else if (regno == BZ || regno == VR || regno == WZ || regno == DZ) { + /* Read-only registers. */ + status = E02; + + } else if (regno == PID) { + /* 32-bit register. (Even though we already checked SRS and WZ, we cannot + combine this with the EXS - SPC write since SRS and WZ have different size.) */ + hex2mem((unsigned char *)®.pid, val, sizeof(unsigned int)); + + } else if (regno == SRS) { + /* 8-bit register. */ + hex2mem((unsigned char *)®.srs, val, sizeof(unsigned char)); + + } else if (regno >= EXS && regno <= SPC) { + /* Consecutive 32-bit registers. */ + hex2mem((unsigned char *)®.exs + (regno - EXS) * sizeof(unsigned int), + val, sizeof(unsigned int)); + + } else if (regno == PC) { + /* Pseudo-register. Treat as read-only. */ + status = E02; + + } else if (regno >= S0 && regno <= S15) { + /* 32-bit registers. */ + hex2mem((unsigned char *)&sreg.s0_0 + (reg.srs * 16 * sizeof(unsigned int)) + (regno - S0) * sizeof(unsigned int), val, sizeof(unsigned int)); + } else { + /* Non-existing register. */ + status = E05; + } + return status; +} + +/* Read a value from a specified register in the register image. Returns the + value in the register or -1 for non-implemented registers. */ +static int +read_register(char regno, unsigned int *valptr) +{ + int status = SUCCESS; + + /* We read the zero registers from the register struct (instead of just returning 0) + to catch errors. */ + + if (regno >= R0 && regno <= ACR) { + /* Consecutive 32-bit registers. */ + *valptr = *(unsigned int *)((char *)®.r0 + (regno - R0) * sizeof(unsigned int)); + + } else if (regno == BZ || regno == VR) { + /* Consecutive 8-bit registers. */ + *valptr = (unsigned int)(*(unsigned char *) + ((char *)®.bz + (regno - BZ) * sizeof(char))); + + } else if (regno == PID) { + /* 32-bit register. */ + *valptr = *(unsigned int *)((char *)®.pid); + + } else if (regno == SRS) { + /* 8-bit register. */ + *valptr = (unsigned int)(*(unsigned char *)((char *)®.srs)); + + } else if (regno == WZ) { + /* 16-bit register. */ + *valptr = (unsigned int)(*(unsigned short *)(char *)®.wz); + + } else if (regno >= EXS && regno <= PC) { + /* Consecutive 32-bit registers. */ + *valptr = *(unsigned int *)((char *)®.exs + (regno - EXS) * sizeof(unsigned int)); + + } else if (regno >= S0 && regno <= S15) { + /* Consecutive 32-bit registers, located elsewhere. */ + *valptr = *(unsigned int *)((char *)&sreg.s0_0 + (reg.srs * 16 * sizeof(unsigned int)) + (regno - S0) * sizeof(unsigned int)); + + } else { + /* Non-existing register. */ + status = E05; + } + return status; + +} + +/********************************** 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 char * +mem2hex(char *buf, unsigned char *mem, int count) +{ + int i; + int ch; + + if (mem == NULL) { + /* Invalid address, caught by 'm' packet handler. */ + 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; +} + +/* Same as mem2hex, but puts it in network byte order. */ +static char * +mem2hex_nbo(char *buf, unsigned char *mem, int count) +{ + int i; + int ch; + + mem += count - 1; + 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; + } + + if (count >= BUFMAX) + continue; + + 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 len) +{ + /* Move SPC forward if we are single-stepping. */ + asm("spchere:"); + asm("move $spc, $r10"); + asm("cmp.d spchere, $r10"); + asm("bne nosstep"); + asm("nop"); + asm("move.d spccont, $r10"); + asm("move $r10, $spc"); + asm("nosstep:"); + + output_buffer[0] = 'O'; + mem2hex(&output_buffer[1], (unsigned char *)str, len); + putpacket(output_buffer); + + asm("spccont:"); +} + +/********************************** 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 = output_buffer; + unsigned int reg_cont; + + /* Send trap type (converted to signal) */ + + *ptr++ = 'T'; + *ptr++ = highhex(sigval); + *ptr++ = lowhex(sigval); + + if (((reg.exs & 0xff00) >> 8) == 0xc) { + + /* Some kind of hardware watchpoint triggered. Find which one + and determine its type (read/write/access). */ + int S, bp, trig_bits = 0, rw_bits = 0; + int trig_mask = 0; + unsigned int *bp_d_regs = &sreg.s3_3; + /* In a lot of cases, the stopped data address will simply be EDA. + In some cases, we adjust it to match the watched data range. + (We don't want to change the actual EDA though). */ + unsigned int stopped_data_address; + /* The S field of EXS. */ + S = (reg.exs & 0xffff0000) >> 16; + + if (S & 1) { + /* Instruction watchpoint. */ + /* FIXME: Check against, and possibly adjust reported EDA. */ + } else { + /* Data watchpoint. Find the one that triggered. */ + for (bp = 0; bp < 6; bp++) { + + /* Dx_RD, Dx_WR in the S field of EXS for this BP. */ + int bitpos_trig = 1 + bp * 2; + /* Dx_BPRD, Dx_BPWR in BP_CTRL for this BP. */ + int bitpos_config = 2 + bp * 4; + + /* Get read/write trig bits for this BP. */ + trig_bits = (S & (3 << bitpos_trig)) >> bitpos_trig; + + /* Read/write config bits for this BP. */ + rw_bits = (sreg.s0_3 & (3 << bitpos_config)) >> bitpos_config; + if (trig_bits) { + /* Sanity check: the BP shouldn't trigger for accesses + that it isn't configured for. */ + if ((rw_bits == 0x1 && trig_bits != 0x1) || + (rw_bits == 0x2 && trig_bits != 0x2)) + panic("Invalid r/w trigging for this BP"); + + /* Mark this BP as trigged for future reference. */ + trig_mask |= (1 << bp); + + if (reg.eda >= bp_d_regs[bp * 2] && + reg.eda <= bp_d_regs[bp * 2 + 1]) { + /* EDA withing range for this BP; it must be the one + we're looking for. */ + stopped_data_address = reg.eda; + break; + } + } + } + if (bp < 6) { + /* Found a trigged BP with EDA within its configured data range. */ + } else if (trig_mask) { + /* Something triggered, but EDA doesn't match any BP's range. */ + for (bp = 0; bp < 6; bp++) { + /* Dx_BPRD, Dx_BPWR in BP_CTRL for this BP. */ + int bitpos_config = 2 + bp * 4; + + /* Read/write config bits for this BP (needed later). */ + rw_bits = (sreg.s0_3 & (3 << bitpos_config)) >> bitpos_config; + + if (trig_mask & (1 << bp)) { + /* EDA within 31 bytes of the configured start address? */ + if (reg.eda + 31 >= bp_d_regs[bp * 2]) { + /* Changing the reported address to match + the start address of the first applicable BP. */ + stopped_data_address = bp_d_regs[bp * 2]; + break; + } else { + /* We continue since we might find another useful BP. */ + printk("EDA doesn't match trigged BP's range"); + } + } + } + } + + /* No match yet? */ + BUG_ON(bp >= 6); + /* Note that we report the type according to what the BP is configured + for (otherwise we'd never report an 'awatch'), not according to how + it trigged. We did check that the trigged bits match what the BP is + configured for though. */ + if (rw_bits == 0x1) { + /* read */ + strncpy(ptr, "rwatch", 6); + ptr += 6; + } else if (rw_bits == 0x2) { + /* write */ + strncpy(ptr, "watch", 5); + ptr += 5; + } else if (rw_bits == 0x3) { + /* access */ + strncpy(ptr, "awatch", 6); + ptr += 6; + } else { + panic("Invalid r/w bits for this BP."); + } + + *ptr++ = ':'; + /* Note that we don't read_register(EDA, ...) */ + ptr = mem2hex_nbo(ptr, (unsigned char *)&stopped_data_address, register_size[EDA]); + *ptr++ = ';'; + } + } + /* Only send PC, frame and stack pointer. */ + read_register(PC, ®_cont); + *ptr++ = highhex(PC); + *ptr++ = lowhex(PC); + *ptr++ = ':'; + ptr = mem2hex(ptr, (unsigned char *)®_cont, register_size[PC]); + *ptr++ = ';'; + + read_register(R8, ®_cont); + *ptr++ = highhex(R8); + *ptr++ = lowhex(R8); + *ptr++ = ':'; + ptr = mem2hex(ptr, (unsigned char *)®_cont, register_size[R8]); + *ptr++ = ';'; + + read_register(SP, ®_cont); + *ptr++ = highhex(SP); + *ptr++ = lowhex(SP); + *ptr++ = ':'; + ptr = mem2hex(ptr, (unsigned char *)®_cont, register_size[SP]); + *ptr++ = ';'; + + /* Send ERP as well; this will save us an entire register fetch in some cases. */ + read_register(ERP, ®_cont); + *ptr++ = highhex(ERP); + *ptr++ = lowhex(ERP); + *ptr++ = ':'; + ptr = mem2hex(ptr, (unsigned char *)®_cont, register_size[ERP]); + *ptr++ = ';'; + + /* null-terminate and send it off */ + *ptr = 0; + putpacket(output_buffer); +} + +/* Returns the size of an instruction that has a delay slot. */ + +int insn_size(unsigned long pc) +{ + unsigned short opcode = *(unsigned short *)pc; + int size = 0; + + switch ((opcode & 0x0f00) >> 8) { + case 0x0: + case 0x9: + case 0xb: + size = 2; + break; + case 0xe: + case 0xf: + size = 6; + break; + case 0xd: + /* Could be 4 or 6; check more bits. */ + if ((opcode & 0xff) == 0xff) + size = 4; + else + size = 6; + break; + default: + panic("Couldn't find size of opcode 0x%x at 0x%lx\n", opcode, pc); + } + + return size; +} + +void register_fixup(int sigval) +{ + /* Compensate for ACR push at the beginning of exception handler. */ + reg.sp += 4; + + /* Standard case. */ + reg.pc = reg.erp; + if (reg.erp & 0x1) { + /* Delay slot bit set. Report as stopped on proper instruction. */ + if (reg.spc) { + /* Rely on SPC if set. */ + reg.pc = reg.spc; + } else { + /* Calculate the PC from the size of the instruction |