patch-2.1.113 linux/arch/m68k/kernel/kgdb.c
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- Lines: 1195
- Date:
Thu Jul 30 11:08:19 1998
- Orig file:
v2.1.112/linux/arch/m68k/kernel/kgdb.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.1.112/linux/arch/m68k/kernel/kgdb.c linux/arch/m68k/kernel/kgdb.c
@@ -0,0 +1,1194 @@
+/*
+ * arch/m68k/kernel/kgdb.c -- Stub for GDB remote debugging protocol
+ *
+ * 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
+ * Modified and extended for Linux/68k by Roman Hodek
+ *
+ * Send complaints, suggestions etc. to
+ * <Roman.Hodek@informatik.uni-erlangen.de>
+ *
+ * Copyright (C) 1996-97 Roman Hodek
+ */
+
+/*
+ * kgdb usage notes:
+ * -----------------
+ *
+ * If you select CONFIG_KGDB in the configuration, the kernel will be built
+ * with different gccc 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 9600bps, for easyness of
+ * implementation.
+ *
+ * Of course, you need a remote machine a suitable gdb there. I.e., it must
+ * have support for a m68k-linux target built in. If the remote machine
+ * doesn't run Linux/68k itself, you have to build a cross gdb. This is done
+ * by
+ * ./configure --target=m68k-linux
+ * in the gdb source directory. Until gdb comes with m68k-linux support by
+ * default, you have to apply some patches before. The remote debugging
+ * protocol itself is always built into gdb anyway, so you don't have to take
+ * special care about it.
+ *
+ * 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.)
+ *
+ * - 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.
+ * (Linux/68k note: Due to the current design, kgdb has to be initialized
+ * after traps and interrupts.)
+ * Two, a breakpoint needs to be generated to begin communication. This
+ * is most easily accomplished by a call to breakpoint(). Breakpoint()
+ * simulates a breakpoint by executing a TRAP #15 instruction.
+ *
+ *
+ * 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/config.h>
+#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/traps.h>
+#include <asm/machdep.h>
+#include <asm/kgdb.h>
+#ifdef CONFIG_ATARI
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+#endif
+#ifdef CONFIG_AMIGA
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+#endif
+
+
+#undef DEBUG
+
+/*
+ * global variable: register structure
+ */
+
+struct gdb_regs kgdb_registers;
+
+/*
+ * serial i/o functions
+ */
+
+static int (*serial_out)( unsigned char c );
+static unsigned char (*serial_in)( void );
+static unsigned char (*serial_intr)( void );
+
+#define putDebugChar(c) serial_out(c)
+#define getDebugChar() serial_in()
+
+
+/***************************** Prototypes *****************************/
+
+static int hex( unsigned char ch);
+static void getpacket( char *buffer);
+static void putpacket( char *buffer, int expect_ack);
+static inline unsigned long *get_vbr( void );
+static int protected_read( char *p, unsigned long *vbr );
+static int protected_write( char *p, char val, unsigned long *vbr );
+static unsigned char *mem2hex( char *mem, char *buf, int count, int
+ may_fault);
+static char *hex2mem( char *buf, char *mem, int count, int may_fault);
+static int computeSignal( int tt);
+static int hexToInt( char **ptr, int *intValue);
+extern asmlinkage void kgdb_intr( int intno, void *data, struct pt_regs *fp );
+static asmlinkage void handle_exception( void );
+static void show_gdbregs( void );
+#ifdef CONFIG_ATARI
+static int atari_mfp_out( unsigned char c );
+static unsigned char atari_mfp_in( void );
+static unsigned char atari_mfp_intr( void );
+static int atari_scc_out( unsigned char c );
+static unsigned char atari_scc_in( void );
+static unsigned char atari_scc_intr( void );
+#endif
+#ifdef CONFIG_AMIGA
+extern int amiga_ser_out( unsigned char c );
+extern unsigned char amiga_ser_in( void );
+#endif
+
+/************************* End of Prototypes **************************/
+
+
+int kgdb_initialized = 0; /* !0 means we've been initialized */
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound buffers
+ * at least NUMREGBYTES*2 are needed for register packets
+ */
+#define BUFMAX 2048
+
+static char input_buffer[BUFMAX];
+static char output_buffer[BUFMAX];
+static const char hexchars[]="0123456789abcdef";
+/* debug > 0 prints ill-formed commands in valid packets & checksum errors */
+static int remote_debug = 0;
+
+/* sizes (in bytes) of CPU stack frames */
+static int frame_sizes[16] = {
+ 8, 8, 12, 12, /* $0..$3 */
+ 16, 8, 8, 60, /* $4..$7 */
+ 8, 20, 32, 92, /* $8..$B */
+ 12, 4, 4, 4 /* $C..$F */
+};
+
+/*
+ * Convert ch from a hex digit to an int
+ */
+static int hex(unsigned 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;
+}
+
+/*
+ * scan for the sequence $<data>#<checksum>
+ */
+static void getpacket(char *buffer)
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ unsigned char ch;
+
+ do {
+ /*
+ * wait around for the start character,
+ * ignore all other characters
+ */
+ while ((ch = (getDebugChar() & 0x7f)) != '$') ;
+
+ checksum = 0;
+ xmitcsum = -1;
+ count = 0;
+
+ /*
+ * now, read until a # or end of buffer is found
+ */
+ while (count < BUFMAX) {
+ ch = getDebugChar() & 0x7f;
+ if (ch == '#')
+ break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+
+ if (count >= BUFMAX)
+ continue;
+
+ buffer[count] = 0;
+#ifdef DEBUG
+ printk( "kgdb: received packet %s\n", buffer );
+#endif
+
+ if (ch == '#') {
+ xmitcsum = hex(getDebugChar() & 0x7f) << 4;
+ xmitcsum |= hex(getDebugChar() & 0x7f);
+
+ if (checksum != xmitcsum) {
+ if (remote_debug)
+ printk( "kgdb: bad checksum. count = 0x%x sent=0x%x "
+ "buf=%s\n", checksum, xmitcsum, buffer );
+ putDebugChar('-'); /* failed checksum */
+ }
+ else {
+ putDebugChar('+'); /* successful transfer */
+
+ /*
+ * if a sequence char is present,
+ * reply the sequence ID
+ */
+ if (buffer[2] == ':') {
+ putDebugChar(buffer[0]);
+ putDebugChar(buffer[1]);
+
+ /*
+ * remove sequence chars from buffer
+ */
+ count = strlen(buffer);
+ for (i=3; i <= count; i++)
+ buffer[i-3] = buffer[i];
+ }
+ }
+ }
+ }
+ while (checksum != xmitcsum);
+}
+
+/*
+ * send the packet in buffer.
+ */
+static void putpacket(char *buffer, int expect_ack)
+{
+ unsigned char checksum;
+ int count;
+ unsigned char ch;
+
+ /*
+ * $<packet info>#<checksum>.
+ */
+
+#ifdef DEBUG
+ printk( "kgdb: sending packet %s\n", buffer );
+#endif
+ do {
+ putDebugChar('$');
+ checksum = 0;
+ count = 0;
+
+ while ((ch = buffer[count]) != 0) {
+ if (!(putDebugChar(ch)))
+ return;
+ checksum += ch;
+ count += 1;
+ }
+
+ putDebugChar('#');
+ putDebugChar(hexchars[checksum >> 4]);
+ putDebugChar(hexchars[checksum & 0xf]);
+
+ }
+ while (expect_ack && (getDebugChar() & 0x7f) != '+');
+}
+
+
+static inline unsigned long *get_vbr( void )
+
+{ unsigned long *vbr;
+
+ __asm__ __volatile__ ( "movec %/vbr,%0" : "=d" (vbr) : );
+ return( vbr );
+}
+
+static int protected_read( char *p, unsigned long *vbr )
+
+{ unsigned char val;
+ int rv;
+
+ __asm__ __volatile__
+ ( "movel %3@(8),%/a0\n\t"
+ "movel #Lberr1,%3@(8)\n\t"
+ "movel %/sp,%/a1\n\t"
+ "moveq #1,%1\n\t"
+ "moveb %2@,%0\n"
+ "nop \n\t"
+ "moveq #0,%1\n\t"
+ "Lberr1:\t"
+ "movel %/a1,%/sp\n\t"
+ "movel %/a0,%3@(8)"
+ : "=&d" (val), "=&r" (rv)
+ : "a" (p), "a" (vbr)
+ : "a0", "a1" );
+
+ return( rv ? -1 : val );
+}
+
+static int protected_write( char *p, char val, unsigned long *vbr )
+
+{ int rv;
+
+ __asm__ __volatile__
+ ( "movel %3@(8),%/a0\n\t"
+ "movel #Lberr2,%3@(8)\n\t"
+ "movel %/sp,%/a1\n\t"
+ "moveq #1,%0\n\t"
+ "moveb %2,%1@\n"
+ "nop \n\t"
+ "moveq #0,%0\n\t"
+ "Lberr2:\t"
+ "movel %/a1,%/sp\n\t"
+ "movel %/a0,%3@(8)"
+ : "=&r" (rv)
+ : "a" (p), "d" (val), "a" (vbr)
+ : "a0", "a1" );
+
+ return( rv );
+}
+
+/*
+ * Convert the memory pointed to by mem into hex, placing result in buf.
+ * Return a pointer to the last char put in buf (null), in case of mem fault,
+ * return 0.
+ * If MAY_FAULT is non-zero, then we will handle memory faults by returning
+ * a 0, else treat a fault like any other fault in the stub.
+ */
+static unsigned char *mem2hex(char *mem, char *buf, int count, int may_fault)
+{
+ int ch;
+ unsigned long *vbr = get_vbr();
+
+ for( ; count-- > 0; ++mem ) {
+ if ((ch = protected_read( mem, vbr )) < 0) {
+ /* bus error happened */
+ if (may_fault)
+ return 0;
+ else {
+ /* ignore, but print a warning */
+ printk( "Bus error on read from %p\n", mem );
+ ch = 0;
+ }
+ }
+ *buf++ = hexchars[(ch >> 4) & 0xf];
+ *buf++ = hexchars[ch & 0xf];
+ }
+
+ *buf = 0;
+
+ return buf;
+}
+
+/*
+ * convert the hex array pointed to by buf into binary to be placed in mem
+ * return a pointer to the character AFTER the last byte written
+ */
+static char *hex2mem(char *buf, char *mem, int count, int may_fault)
+{
+ int i;
+ unsigned char ch;
+ unsigned long *vbr = get_vbr();
+
+ for( i = 0; i < count; i++, mem++ ) {
+ ch = hex(*buf++) << 4;
+ ch |= hex(*buf++);
+ if (protected_write( mem, ch, vbr )) {
+ /* bus error happened */
+ if (may_fault)
+ return 0;
+ else
+ /* ignore, but print a warning */
+ printk( "Bus error on write to %p\n", mem );
+ }
+ }
+
+ return mem;
+}
+
+/*
+ * This table contains the mapping between SPARC hardware trap types, and
+ * signals, which are primarily what GDB understands. It also indicates
+ * which hardware traps we need to commandeer when initializing the stub.
+ */
+static struct hard_trap_info
+{
+ unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
+ unsigned char signo; /* Signal that we map this trap into */
+} hard_trap_info[] = {
+ { 1, SIGINT }, /* excep. 1 is used to fake SIGINT */
+ { VEC_BUSERR, SIGSEGV }, /* bus/access error */
+ { VEC_ADDRERR, SIGBUS }, /* address error */
+ { VEC_ILLEGAL, SIGILL }, /* illegal insn */
+ { VEC_ZERODIV, SIGFPE }, /* (integer) divison by zero */
+ { VEC_CHK, SIGILL }, /* CHK insn */
+ { VEC_TRAP, SIGFPE }, /* [F]TRAPcc insn */
+ { VEC_PRIV, SIGILL }, /* priviledge violation (cannot happen) */
+ { VEC_TRACE, SIGTRAP }, /* trace trap (single-stepping) */
+ { VEC_LINE10, SIGILL }, /* A-line insn */
+ { VEC_LINE11, SIGILL }, /* F-line insn */
+ { VEC_COPROC, SIGIOT }, /* coprocessor protocol error */
+ { VEC_FORMAT, SIGIOT }, /* frame format error */
+ { VEC_UNINT, SIGIOT }, /* uninitialized intr. (should not happen) */
+ { VEC_SYS, SIGILL }, /* TRAP #0 = system call (illegal in kernel) */
+ { VEC_TRAP1, SIGILL }, /* TRAP #1 */
+ { VEC_TRAP2, SIGILL }, /* TRAP #2 */
+ { VEC_TRAP3, SIGILL }, /* TRAP #3 */
+ { VEC_TRAP4, SIGILL }, /* TRAP #4 */
+ { VEC_TRAP5, SIGILL }, /* TRAP #5 */
+ { VEC_TRAP6, SIGILL }, /* TRAP #6 */
+ { VEC_TRAP7, SIGILL }, /* TRAP #7 */
+ { VEC_TRAP8, SIGILL }, /* TRAP #8 */
+ { VEC_TRAP9, SIGILL }, /* TRAP #9 */
+ { VEC_TRAP10, SIGILL }, /* TRAP #10 */
+ { VEC_TRAP11, SIGILL }, /* TRAP #11 */
+ { VEC_TRAP12, SIGILL }, /* TRAP #12 */
+ { VEC_TRAP13, SIGILL }, /* TRAP #13 */
+ { VEC_TRAP14, SIGABRT }, /* TRAP #14 (used by kgdb_abort) */
+ { VEC_TRAP15, SIGTRAP }, /* TRAP #15 (breakpoint) */
+ { VEC_FPBRUC, SIGFPE }, /* FPU */
+ { VEC_FPIR, SIGFPE }, /* FPU */
+ { VEC_FPDIVZ, SIGFPE }, /* FPU */
+ { VEC_FPUNDER, SIGFPE }, /* FPU */
+ { VEC_FPOE, SIGFPE }, /* FPU */
+ { VEC_FPOVER, SIGFPE }, /* FPU */
+ { VEC_FPNAN, SIGFPE }, /* FPU */
+ { VEC_FPUNSUP, SIGFPE }, /* FPU */
+ { VEC_UNIMPEA, SIGILL }, /* unimpl. effective address */
+ { VEC_UNIMPII, SIGILL }, /* unimpl. integer insn */
+
+ { 0, 0 } /* Must be last */
+};
+
+
+/*
+ * Set up exception handlers for tracing and breakpoints
+ */
+void kgdb_init(void)
+{
+ extern char m68k_debug_device[];
+
+ /* fake usage to avoid gcc warnings about unused stuff (they're used in
+ * assembler code) The local variables will be optimized away... */
+ void (*fake1)(void) = handle_exception;
+ int *fake2 = frame_sizes;
+ (void)fake1; (void)fake2;
+
+ /* We don't modify the real exception vectors here for the m68k.
+ * handle_exception() will be called from bad_kernel_trap() or
+ * die_if_kernel() as needed. */
+
+ /*
+ * Initialize the serial port (name in 'm68k_debug_device')
+ */
+
+ serial_in = NULL;
+ serial_out = NULL;
+ serial_intr = NULL;
+
+#ifdef CONFIG_ATARI
+ if (MACH_IS_ATARI) {
+ if (!strcmp( m68k_debug_device, "ser" )) {
+ /* defaults to ser2 for a Falcon and ser1 otherwise */
+ strcpy( m68k_debug_device,
+ ((atari_mch_cookie>>16) == ATARI_MCH_FALCON) ?
+ "ser2" : "ser1" );
+ }
+
+ if (!strcmp( m68k_debug_device, "ser1" )) {
+ /* ST-MFP Modem1 serial port init */
+ mfp.trn_stat &= ~0x01; /* disable TX */
+ mfp.rcv_stat &= ~0x01; /* disable RX */
+ mfp.usart_ctr = 0x88; /* clk 1:16, 8N1 */
+ mfp.tim_ct_cd &= 0x70; /* stop timer D */
+ mfp.tim_dt_d = 2; /* 9600 bps */
+ mfp.tim_ct_cd |= 0x01; /* start timer D, 1:4 */
+ mfp.trn_stat |= 0x01; /* enable TX */
+ mfp.rcv_stat |= 0x01; /* enable RX */
+
+ /* set function pointers */
+ serial_in = atari_mfp_in;
+ serial_out = atari_mfp_out;
+ serial_intr = atari_mfp_intr;
+
+ /* allocate interrupt */
+ request_irq( IRQ_MFP_RECFULL, kgdb_intr, IRQ_TYPE_FAST, "kgdb",
+ NULL );
+ }
+ else if (!strcmp( m68k_debug_device, "ser2" )) {
+ extern int atari_SCC_reset_done;
+
+ /* SCC Modem2 serial port init */
+ static unsigned char *p, scc_table[] = {
+ 9, 0xc0, /* Reset */
+ 4, 0x44, /* x16, 1 stopbit, no parity */
+ 3, 0xc0, /* receiver: 8 bpc */
+ 5, 0xe2, /* transmitter: 8 bpc, assert dtr/rts */
+ 2, 0x60, /* base int vector */
+ 9, 0x09, /* int enab, with status low */
+ 10, 0, /* NRZ */
+ 11, 0x50, /* use baud rate generator */
+ 12, 24, 13, 0, /* 9600 baud */
+ 14, 2, 14, 3, /* use master clock for BRG, enable */
+ 3, 0xc1, /* enable receiver */
+ 5, 0xea, /* enable transmitter */
+ 15, 0, /* no stat ints */
+ 1, 0x10, /* Rx int every char, other ints off */
+ 0
+ };
+
+ (void)scc.cha_b_ctrl; /* reset reg pointer */
+ MFPDELAY();
+ for( p = scc_table; *p != 0; ) {
+ scc.cha_b_ctrl = *p++;
+ MFPDELAY();
+ scc.cha_b_ctrl = *p++;
+ MFPDELAY();
+ if (p[-2] == 9)
+ udelay(40); /* extra delay after WR9 access */
+ }
+ /* avoid that atari_SCC.c resets the whole SCC again */
+ atari_SCC_reset_done = 1;
+
+ /* set function pointers */
+ serial_in = atari_scc_in;
+ serial_out = atari_scc_out;
+ serial_intr = atari_scc_intr;
+
+ /* allocate rx and spcond ints */
+ request_irq( IRQ_SCCB_RX, kgdb_intr, IRQ_TYPE_FAST, "kgdb", NULL );
+ request_irq( IRQ_SCCB_SPCOND, kgdb_intr, IRQ_TYPE_FAST, "kgdb",
+ NULL );
+ }
+ }
+#endif
+
+#ifdef CONFIG_AMIGA
+ if (MACH_IS_AMIGA) {
+ /* always use built-in serial port, no init required */
+ serial_in = amiga_ser_in;
+ serial_out = amiga_ser_out;
+ }
+#endif
+
+#ifdef CONFIG_ATARI
+ if (!serial_in || !serial_out) {
+ if (*m68k_debug_device)
+ printk( "kgdb_init failed: no valid serial device!\n" );
+ else
+ printk( "kgdb not enabled\n" );
+ return;
+ }
+#endif
+
+ /*
+ * In case GDB is started before us, ack any packets
+ * (presumably "$?#xx") sitting there.
+ */
+
+ putDebugChar ('+');
+ kgdb_initialized = 1;
+ printk( KERN_INFO "kgdb initialized.\n" );
+}
+
+
+/*
+ * Convert the MIPS hardware trap type code to a unix signal number.
+ */
+static int computeSignal(int tt)
+{
+ struct hard_trap_info *ht;
+
+ for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+ if (ht->tt == tt)
+ return ht->signo;
+
+ return SIGHUP; /* default for things we don't know about */
+}
+
+/*
+ * While we find nice hex chars, build an int.
+ * Return number of chars processed.
+ */
+static int hexToInt(char **ptr, int *intValue)
+{
+ int numChars = 0;
+ int hexValue;
+
+ *intValue = 0;
+
+ while (**ptr)
+ {
+ hexValue = hex(**ptr);
+ if (hexValue < 0)
+ break;
+
+ *intValue = (*intValue << 4) | hexValue;
+ numChars ++;
+
+ (*ptr)++;
+ }
+
+ return (numChars);
+}
+
+
+/*
+ * This assembler stuff copies a struct frame (passed as argument) into struct
+ * gdb_regs registers and then calls handle_exception. After return from
+ * there, register and the like are restored from 'registers', the stack is
+ * set up and execution is continued where registers->pc tells us.
+ */
+
+/* offsets in struct frame */
+#define FRAMEOFF_D1 "0" /* d1..d5 */
+#define FRAMEOFF_A0 "5*4" /* a0..a2 */
+#define FRAMEOFF_D0 "8*4"
+#define FRAMEOFF_SR "11*4"
+#define FRAMEOFF_PC "11*4+2"
+#define FRAMEOFF_VECTOR "12*4+2"
+
+/* offsets in struct gdb_regs */
+#define GDBOFF_D0 "0"
+#define GDBOFF_D1 "1*4"
+#define GDBOFF_D6 "6*4"
+#define GDBOFF_A0 "8*4"
+#define GDBOFF_A3 "11*4"
+#define GDBOFF_A7 "15*4"
+#define GDBOFF_VECTOR "16*4"
+#define GDBOFF_SR "16*4+2"
+#define GDBOFF_PC "17*4"
+#define GDBOFF_FP0 "18*4"
+#define GDBOFF_FPCTL "42*4"
+
+__asm__
+( " .globl " SYMBOL_NAME_STR(enter_kgdb) "\n"
+ SYMBOL_NAME_STR(enter_kgdb) ":\n"
+ /* return if not initialized */
+ " tstl "SYMBOL_NAME_STR(kgdb_initialized)"\n"
+ " bne 1f\n"
+ " rts \n"
+ "1: orw #0x700,%sr\n" /* disable interrupts while in stub */
+ " tstl %sp@+\n" /* pop off return address */
+ " movel %sp@+,%a0\n" /* get pointer to fp->ptregs (param) */
+ " movel #"SYMBOL_NAME_STR(kgdb_registers)",%a1\n" /* destination */
+ /* copy d0-d5/a0-a1 into gdb_regs */
+ " movel %a0@("FRAMEOFF_D0"),%a1@("GDBOFF_D0")\n"
+ " moveml %a0@("FRAMEOFF_D1"),%d1-%d5\n"
+ " moveml %d1-%d5,%a1@("GDBOFF_D1")\n"
+ " moveml %a0@("FRAMEOFF_A0"),%d0-%d2\n"
+ " moveml %d0-%d2,%a1@("GDBOFF_A0")\n"
+ /* copy sr and pc */
+ " movel %a0@("FRAMEOFF_PC"),%a1@("GDBOFF_PC")\n"
+ " movew %a0@("FRAMEOFF_SR"),%a1@("GDBOFF_SR")\n"
+ /* copy format/vector word */
+ " movew %a0@("FRAMEOFF_VECTOR"),%a1@("GDBOFF_VECTOR")\n"
+ /* save FPU regs */
+ " fmovemx %fp0-%fp7,%a1@("GDBOFF_FP0")\n"
+ " fmoveml %fpcr/%fpsr/%fpiar,%a1@("GDBOFF_FPCTL")\n"
+
+ /* set stack to CPU frame */
+ " addl #"FRAMEOFF_SR",%a0\n"
+ " movel %a0,%sp\n"
+ " movew %sp@(6),%d0\n"
+ " andl #0xf000,%d0\n"
+ " lsrl #8,%d0\n"
+ " lsrl #2,%d0\n" /* get frame format << 2 */
+ " lea "SYMBOL_NAME_STR(frame_sizes)",%a2\n"
+ " addl %a2@(%d0),%sp\n"
+ " movel %sp,%a1@("GDBOFF_A7")\n" /* save a7 now */
+
+ /* call handle_exception() now that the stack is set up */
+ "Lcall_handle_excp:"
+ " jsr "SYMBOL_NAME_STR(handle_exception)"\n"
+
+ /* after return, first restore FPU registers */
+ " movel #"SYMBOL_NAME_STR(kgdb_registers)",%a0\n" /* source */
+ " fmovemx %a0@("GDBOFF_FP0"),%fp0-%fp7\n"
+ " fmoveml %a0@("GDBOFF_FPCTL"),%fpcr/%fpsr/%fpiar\n"
+ /* set new stack pointer */
+ " movel %a0@("GDBOFF_A7"),%sp\n"
+ " clrw %sp@-\n" /* fake format $0 frame */
+ " movel %a0@("GDBOFF_PC"),%sp@-\n" /* new PC into frame */
+ " movew %a0@("GDBOFF_SR"),%sp@-\n" /* new SR into frame */
+ /* restore general registers */
+ " moveml %a0@("GDBOFF_D0"),%d0-%d7/%a0-%a6\n"
+ /* and jump to new PC */
+ " rte"
+ );
+
+
+/*
+ * This is the entry point for the serial interrupt handler. It calls the
+ * machine specific function pointer 'serial_intr' to get the char that
+ * interrupted. If that was C-c, the stub is entered as above, but based on
+ * just a struct intframe, not a struct frame.
+ */
+
+__asm__
+( SYMBOL_NAME_STR(kgdb_intr) ":\n"
+ /* return if not initialized */
+ " tstl "SYMBOL_NAME_STR(kgdb_initialized)"\n"
+ " bne 1f\n"
+ "2: rts \n"
+ "1: movel "SYMBOL_NAME_STR(serial_intr)",%a0\n"
+ " jsr (%a0)\n" /* get char from serial */
+ " cmpb #3,%d0\n" /* is it C-c ? */
+ " bne 2b\n" /* no -> just ignore */
+ " orw #0x700,%sr\n" /* disable interrupts */
+ " subql #1,"SYMBOL_NAME_STR(local_irq_count)"\n"
+ " movel %sp@(12),%sp\n" /* revert stack to where 'inthandler' set
+ * it up */
+ /* restore regs from frame */
+ " moveml %sp@+,%d1-%d5/%a0-%a2\n"
+ " movel %sp@+,%d0\n"
+ " addql #8,%sp\n" /* throw away orig_d0 and stkadj */
+ /* save them into 'registers' */
+ " moveml %d0-%d7/%a0-%a6,"SYMBOL_NAME_STR(kgdb_registers)"\n"
+ " movel #"SYMBOL_NAME_STR(kgdb_registers)",%a1\n" /* destination */
+ /* copy sr and pc */
+ " movel %sp@(2),%a1@("GDBOFF_PC")\n"
+ " movew %sp@,%a1@("GDBOFF_SR")\n"
+ /* fake format 0 and vector 1 (translated to SIGINT) */
+ " movew #4,%a1@("GDBOFF_VECTOR")\n"
+ /* save FPU regs */
+ " fmovemx %fp0-%fp7,%a1@("GDBOFF_FP0")\n"
+ " fmoveml %fpcr/%fpsr/%fpiar,%a1@("GDBOFF_FPCTL")\n"
+ /* pop off the CPU stack frame */
+ " addql #8,%sp\n"
+ " movel %sp,%a1@("GDBOFF_A7")\n" /* save a7 now */
+ /* proceed as in enter_kgdb */
+ " jbra Lcall_handle_excp\n"
+ );
+
+/*
+ * This function does all command processing for interfacing to gdb. It
+ * returns 1 if you should skip the instruction at the trap address, 0
+ * otherwise.
+ */
+static asmlinkage void handle_exception( void )
+{
+ int trap; /* Trap type */
+ int sigval;
+ int addr;
+ int length;
+ char *ptr;
+
+ trap = kgdb_registers.vector >> 2;
+ sigval = computeSignal(trap);
+ /* clear upper half of vector/sr word */
+ kgdb_registers.vector = 0;
+ kgdb_registers.format = 0;
+
+#ifndef DEBUG
+ if (remote_debug) {
+#endif
+ printk("in handle_exception() trap=%d sigval=%d\n", trap, sigval );
+ show_gdbregs();
+#ifndef DEBUG
+ }
+#endif
+
+ /*
+ * reply to host that an exception has occurred
+ */
+ ptr = output_buffer;
+
+ /*
+ * Send trap type (converted to signal)
+ */
+ *ptr++ = 'T';
+ *ptr++ = hexchars[sigval >> 4];
+ *ptr++ = hexchars[sigval & 0xf];
+
+ /*
+ * Send Error PC
+ */
+ *ptr++ = hexchars[GDBREG_PC >> 4];
+ *ptr++ = hexchars[GDBREG_PC & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&kgdb_registers.pc, ptr, 4, 0);
+ *ptr++ = ';';
+
+ /*
+ * Send frame pointer
+ */
+ *ptr++ = hexchars[GDBREG_A6 >> 4];
+ *ptr++ = hexchars[GDBREG_A6 & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&kgdb_registers.regs[GDBREG_A6], ptr, 4, 0);
+ *ptr++ = ';';
+
+ /*
+ * Send stack pointer
+ */
+ *ptr++ = hexchars[GDBREG_SP >> 4];
+ *ptr++ = hexchars[GDBREG_SP & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&kgdb_registers.regs[GDBREG_SP], ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = 0;
+ putpacket(output_buffer,1); /* send it off... */
+
+ /*
+ * Wait for input from remote GDB
+ */
+ for(;;) {
+ output_buffer[0] = 0;
+ getpacket(input_buffer);
+
+ switch (input_buffer[0]) {
+ case '?':
+ output_buffer[0] = 'S';
+ output_buffer[1] = hexchars[sigval >> 4];
+ output_buffer[2] = hexchars[sigval & 0xf];
+ output_buffer[3] = 0;
+ break;
+
+ case 'd':
+ /* toggle debug flag */
+ remote_debug = !remote_debug;
+ break;
+
+ /*
+ * Return the value of the CPU registers
+ */
+ case 'g':
+ ptr = output_buffer;
+ ptr = mem2hex((char *)&kgdb_registers, ptr, NUMREGSBYTES, 0);
+ break;
+
+ /*
+ * set the value of the CPU registers - return OK
+ */
+ case 'G':
+ ptr = &input_buffer[1];
+ ptr = hex2mem(ptr, (char *)&kgdb_registers, NUMREGSBYTES, 0);
+ strcpy(output_buffer,"OK");
+ break;
+
+ /*
+ * Pn...=r... Write register n
+ */
+ case 'P':
+ ptr = &input_buffer[1];
+ if (hexToInt(&ptr, &addr) && *ptr++ == '=') {
+ if (addr >= 0 && addr <= GDBREG_PC)
+ hex2mem(ptr, (char *)&kgdb_registers.regs[addr], 4, 0);
+ else if (addr >= GDBREG_FP0 && addr <= GDBREG_FP7)
+ hex2mem(ptr, (char *)&kgdb_registers.fpregs[addr-GDBREG_FP0],
+ 12, 0);
+ else if (addr >= GDBREG_FPCR && addr <= GDBREG_FPIAR)
+ hex2mem(ptr, (char *)&kgdb_registers.fpcntl[addr-GDBREG_FPCR],
+ 4, 0);
+ }
+ else
+ strcpy(output_buffer,"E01");
+ break;
+
+ /*
+ * mAA..AA,LLLL Read LLLL bytes at address AA..AA
+ */
+ case 'm':
+ ptr = &input_buffer[1];
+
+ if (hexToInt(&ptr, &addr)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length)) {
+ if (mem2hex((char *)addr, output_buffer, length, 1))
+ break;
+ strcpy (output_buffer, "E03");
+ } else
+ strcpy(output_buffer,"E01");
+ break;
+
+ /*
+ * MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK
+ */
+ case 'M':
+ ptr = &input_buffer[1];
+
+ if (hexToInt(&ptr, &addr)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length)
+ && *ptr++ == ':') {
+ if (hex2mem(ptr, (char *)addr, length, 1))
+ strcpy(output_buffer, "OK");
+ else
+ strcpy(output_buffer, "E03");
+ }
+ else
+ strcpy(output_buffer, "E02");
+ break;
+
+ /*
+ * cAA..AA Continue at address AA..AA(optional)
+ * sAA..AA Step one instruction from AA..AA(optional)
+ */
+ case 'c':
+ case 's':
+ /* try to read optional parameter, pc unchanged if no parm */
+
+ ptr = &input_buffer[1];
+ if (hexToInt(&ptr, &addr))
+ kgdb_registers.pc = addr;
+
+ kgdb_registers.sr &= 0x7fff; /* clear Trace bit */
+ if (input_buffer[0] == 's')
+ kgdb_registers.sr |= 0x8000; /* set it if step command */
+
+ if (remote_debug)
+ printk( "cont; new PC=0x%08lx SR=0x%04x\n",
+ kgdb_registers.pc, kgdb_registers.sr );
+
+ /*
+ * Need to flush the instruction cache here, as we may
+ * have deposited a breakpoint, and the icache probably
+ * has no way of knowing that a data ref to some location
+ * may have changed something that is in the instruction
+ * cache.
+ */
+
+ if (m68k_is040or060)
+ __asm__ __volatile__
+ ( ".word 0xf4f8\n\t" /* CPUSHA I/D */
+ ".word 0xf498" /* CINVA I */
+ );
+ else
+ __asm__ __volatile__
+ ( "movec %/cacr,%/d0\n\t"
+ "oriw #0x0008,%/d0\n\t"
+ "movec %/d0,%/cacr"
+ : : : "d0" );
+
+ return;
+
+ /*
+ * kill the program means reset the machine
+ */
+ case 'k' :
+ case 'r':
+ if (mach_reset) {
+ /* reply OK before actual reset */
+ strcpy(output_buffer,"OK");
+ putpacket(output_buffer,0);
+ mach_reset();
+ }
+ else
+ strcpy(output_buffer,"E01");
+ break;
+
+ /*
+ * Set baud rate (bBB)
+ * FIXME: Needs to be written (in gdb, too...)
+ */
+ case 'b':
+ strcpy(output_buffer,"E01");
+ break;
+
+ } /* switch */
+
+ /*
+ * reply to the request
+ */
+
+ putpacket(output_buffer,1);
+
+ }
+}
+
+
+/*
+ * Print registers (on target console)
+ * Used only to debug the stub...
+ */
+static void show_gdbregs( void )
+{
+ printk( "d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
+ kgdb_registers.regs[0], kgdb_registers.regs[1],
+ kgdb_registers.regs[2], kgdb_registers.regs[3] );
+ printk( "d4: %08lx d5: %08lx d6: %08lx d7: %08lx\n",
+ kgdb_registers.regs[4], kgdb_registers.regs[5],
+ kgdb_registers.regs[6], kgdb_registers.regs[7] );
+ printk( "a0: %08lx a1: %08lx a2: %08lx a3: %08lx\n",
+ kgdb_registers.regs[8], kgdb_registers.regs[9],
+ kgdb_registers.regs[10], kgdb_registers.regs[11] );
+ printk( "a4: %08lx a5: %08lx a6: %08lx a7: %08lx\n",
+ kgdb_registers.regs[12], kgdb_registers.regs[13],
+ kgdb_registers.regs[14], kgdb_registers.regs[15] );
+ printk( "pc: %08lx sr: %04x\n", kgdb_registers.pc, kgdb_registers.sr );
+}
+
+
+/* -------------------- Atari serial I/O -------------------- */
+
+#ifdef CONFIG_ATARI
+
+static int atari_mfp_out( unsigned char c )
+
+{
+ while( !(mfp.trn_stat & 0x80) ) /* wait for tx buf empty */
+ barrier();
+ mfp.usart_dta = c;
+ return( 1 );
+}
+
+
+static unsigned char atari_mfp_in( void )
+
+{
+ while( !(mfp.rcv_stat & 0x80) ) /* wait for rx buf filled */
+ barrier();
+ return( mfp.usart_dta );
+}
+
+
+static unsigned char atari_mfp_intr( void )
+
+{
+ return( mfp.usart_dta );
+}
+
+
+static int atari_scc_out( unsigned char c )
+
+{
+ do {
+ MFPDELAY();
+ } while( !(scc.cha_b_ctrl & 0x04) ); /* wait for tx buf empty */
+ MFPDELAY();
+ scc.cha_b_data = c;
+ return( 1 );
+}
+
+
+static unsigned char atari_scc_in( void )
+
+{
+ do {
+ MFPDELAY();
+ } while( !(scc.cha_b_ctrl & 0x01) ); /* wait for rx buf filled */
+ MFPDELAY();
+ return( scc.cha_b_data );
+}
+
+
+static unsigned char atari_scc_intr( void )
+
+{ unsigned char c, stat;
+
+ MFPDELAY();
+ scc.cha_b_ctrl = 1; /* RR1 */
+ MFPDELAY();
+ stat = scc.cha_b_ctrl;
+ MFPDELAY();
+ c = scc.cha_b_data;
+ MFPDELAY();
+ if (stat & 0x30) {
+ scc.cha_b_ctrl = 0x30; /* error reset for overrun and parity */
+ MFPDELAY();
+ }
+ scc.cha_b_ctrl = 0x38; /* reset highest IUS */
+ MFPDELAY();
+ return( c );
+}
+
+#endif
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