--- /dev/null
+/****************************************************************************
+
+ THIS SOFTWARE IS NOT COPYRIGHTED
+
+ HP offers the following for use in the public domain. HP makes no
+ warranty with regard to the software or it's performance and the
+ user accepts the software "AS IS" with all faults.
+
+ HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
+ TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+
+****************************************************************************/
+
+/****************************************************************************
+ * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
+ *
+ * Module name: remcom.c $
+ * Revision: 1.34 $
+ * Date: 91/03/09 12:29:49 $
+ * Contributor: Lake Stevens Instrument Division$
+ *
+ * Description: low level support for gdb debugger. $
+ *
+ * Considerations: only works on target hardware $
+ *
+ * Written by: Glenn Engel $
+ * ModuleState: Experimental $
+ *
+ * NOTES: See Below $
+ *
+ * Modified for SPARC by Stu Grossman, Cygnus Support.
+ * Based on sparc-stub.c, it's modified for SPARClite Debug Unit hardware
+ * breakpoint support to create sparclite-stub.c, by Kung Hsu, Cygnus Support.
+ *
+ * This code has been extensively tested on the Fujitsu SPARClite demo board.
+ *
+ * To enable debugger support, two things need to happen. One, a
+ * call to set_debug_traps() 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(). Breakpoint()
+ * simulates a breakpoint by executing a trap #1.
+ *
+ *************
+ *
+ * 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 "defs.h"
+#include <string.h>
+#include <signal.h>
+
+/************************************************************************
+ *
+ * external low-level support routines
+ */
+
+extern putDebugChar(); /* write a single character */
+extern getDebugChar(); /* read and return a single char */
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+#define BUFMAX 2048
+
+static int initialized = 0; /* !0 means we've been initialized */
+
+extern void breakinst();
+static void hw_breakpoint();
+static void set_mem_fault_trap();
+static void get_in_break_mode();
+
+static const char hexchars[]="0123456789abcdef";
+
+#define NUMREGS 80
+
+/* Number of bytes of registers. */
+#define NUMREGBYTES (NUMREGS * 4)
+enum regnames {G0, G1, G2, G3, G4, G5, G6, G7,
+ O0, O1, O2, O3, O4, O5, SP, O7,
+ L0, L1, L2, L3, L4, L5, L6, L7,
+ I0, I1, I2, I3, I4, I5, FP, I7,
+
+ F0, F1, F2, F3, F4, F5, F6, F7,
+ F8, F9, F10, F11, F12, F13, F14, F15,
+ F16, F17, F18, F19, F20, F21, F22, F23,
+ F24, F25, F26, F27, F28, F29, F30, F31,
+ Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR,
+ DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR };
+
+/*************************** ASSEMBLY CODE MACROS *************************/
+/* */
+
+extern void trap_low();
+
+asm("
+ .reserve trapstack, 1000 * 4, \"bss\", 8
+
+ .data
+ .align 4
+
+in_trap_handler:
+ .word 0
+
+ .text
+ .align 4
+
+! This function is called when any SPARC trap (except window overflow or
+! underflow) occurs. It makes sure that the invalid register window is still
+! available before jumping into C code. It will also restore the world if you
+! return from handle_exception.
+
+ .globl _trap_low
+_trap_low:
+ mov %psr, %l0
+ mov %wim, %l3
+
+ srl %l3, %l0, %l4 ! wim >> cwp
+ cmp %l4, 1
+ bne window_fine ! Branch if not in the invalid window
+ nop
+
+! Handle window overflow
+
+ mov %g1, %l4 ! Save g1, we use it to hold the wim
+ srl %l3, 1, %g1 ! Rotate wim right
+ tst %g1
+ bg good_wim ! Branch if new wim is non-zero
+
+! At this point, we need to bring a 1 into the high order bit of the wim.
+! Since we don't want to make any assumptions about the number of register
+! windows, we figure it out dynamically so as to setup the wim correctly.
+
+ not %g1 ! Fill g1 with ones
+ mov %g1, %wim ! Fill the wim with ones
+ nop
+ nop
+ nop
+ mov %wim, %g1 ! Read back the wim
+ inc %g1 ! Now g1 has 1 just to left of wim
+ srl %g1, 1, %g1 ! Now put 1 at top of wim
+ mov %g0, %wim ! Clear wim so that subsequent save
+ nop ! won't trap
+ nop
+ nop
+
+good_wim:
+ save %g0, %g0, %g0 ! Slip into next window
+ mov %g1, %wim ! Install the new wim
+
+ std %l0, [%sp + 0 * 4] ! save L & I registers
+ std %l2, [%sp + 2 * 4]
+ std %l4, [%sp + 4 * 4]
+ std %l6, [%sp + 6 * 4]
+
+ std %i0, [%sp + 8 * 4]
+ std %i2, [%sp + 10 * 4]
+ std %i4, [%sp + 12 * 4]
+ std %i6, [%sp + 14 * 4]
+
+ restore ! Go back to trap window.
+ mov %l4, %g1 ! Restore %g1
+
+window_fine:
+ sethi %hi(in_trap_handler), %l4
+ ld [%lo(in_trap_handler) + %l4], %l5
+ tst %l5
+ bg recursive_trap
+ inc %l5
+
+ set trapstack+1000*4, %sp ! Switch to trap stack
+
+recursive_trap:
+ st %l5, [%lo(in_trap_handler) + %l4]
+ sub %sp,(16+1+6+1+80)*4,%sp ! Make room for input & locals
+ ! + hidden arg + arg spill
+ ! + doubleword alignment
+ ! + registers[72] local var
+
+ std %g0, [%sp + (24 + 0) * 4] ! registers[Gx]
+ std %g2, [%sp + (24 + 2) * 4]
+ std %g4, [%sp + (24 + 4) * 4]
+ std %g6, [%sp + (24 + 6) * 4]
+
+ std %i0, [%sp + (24 + 8) * 4] ! registers[Ox]
+ std %i2, [%sp + (24 + 10) * 4]
+ std %i4, [%sp + (24 + 12) * 4]
+ std %i6, [%sp + (24 + 14) * 4]
+ ! F0->F31 not implemented
+ mov %y, %l4
+ mov %tbr, %l5
+ st %l4, [%sp + (24 + 64) * 4] ! Y
+ st %l0, [%sp + (24 + 65) * 4] ! PSR
+ st %l3, [%sp + (24 + 66) * 4] ! WIM
+ st %l5, [%sp + (24 + 67) * 4] ! TBR
+ st %l1, [%sp + (24 + 68) * 4] ! PC
+ st %l2, [%sp + (24 + 69) * 4] ! NPC
+ ! CPSR and FPSR not impl
+ or %l0, 0xf20, %l4
+ mov %l4, %psr ! Turn on traps, disable interrupts
+ nop
+ nop
+ nop
+ call _get_in_break_mode
+ nop
+ nop
+ nop
+
+ sethi %hi(0xff00), %l5
+ or %l5, %lo(0xff00), %l5
+
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 72) * 4] ! DIA1, debug instr addr 1
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 73) * 4] ! DIA2, debug instr addr 2
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 74) * 4] ! DDA1, debug data addr 1
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 75) * 4] ! DDA2, debug data addr 2
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 76) * 4] ! DDV1, debug data val 1
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 77) * 4] ! DDV2, debug data val 2
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 78) * 4] ! DCR, debug control reg
+ add %l5, 4, %l5
+ lda [%l5]0x1, %l4
+ st %l4, [%sp + (24 + 79) * 4] ! DSR, debug status reg
+ nop
+ nop
+ or %l0, 0xf20, %l4
+ mov %l4, %psr ! Turn on traps, disable interrupts
+ nop
+ nop
+ nop
+ call _handle_exception
+ add %sp, 24 * 4, %o0 ! Pass address of registers
+
+! Reload all of the registers that aren't on the stack
+
+ ld [%sp + (24 + 1) * 4], %g1 ! registers[Gx]
+ ldd [%sp + (24 + 2) * 4], %g2
+ ldd [%sp + (24 + 4) * 4], %g4
+ ldd [%sp + (24 + 6) * 4], %g6
+
+ ldd [%sp + (24 + 8) * 4], %i0 ! registers[Ox]
+ ldd [%sp + (24 + 10) * 4], %i2
+ ldd [%sp + (24 + 12) * 4], %i4
+ ldd [%sp + (24 + 14) * 4], %i6
+
+ sethi %hi(0xff00), %l2
+ or %l2, %lo(0xff00), %l2
+ ldd [%sp + (24 + 72) * 4], %l4 ! DIA1, debug instr addr 1
+ stda %l4, [%l2]0x1
+ nop
+ nop
+ nop
+ nop
+ ldd [%sp + (24 + 74) * 4], %l4 ! DDA1, debug data addr 1
+ add %l2, 8, %l2
+ stda %l4, [%l2]0x1
+ nop
+ nop
+ nop
+ nop
+ ldd [%sp + (24 + 76) * 4], %l4 ! DDV1, debug data value 1
+ add %l2, 8, %l2
+ stda %l4, [%l2]0x1
+ nop
+ nop
+ nop
+ nop
+ ld [%sp + (24 + 78) * 4], %l4 ! DCR, debug control reg
+ ld [%sp + (24 + 79) * 4], %l5 ! DSR, debug control reg
+ add %l2, 8, %l2
+ or %l4, 0x200, %l4
+ sta %l4, [%l2]0x1
+ add %l2, 4, %l2
+ sta %l5, [%l2]0x1
+ nop
+ nop
+ nop
+ nop
+
+ ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR
+ ldd [%sp + (24 + 68) * 4], %l2 ! PC & NPC
+
+ restore ! Ensure that previous window is valid
+ save %g0, %g0, %g0 ! by causing a window_underflow trap
+
+ mov %l0, %y
+ mov %l1, %psr ! Make sure that traps are disabled
+ ! for rett
+ sethi %hi(in_trap_handler), %l4
+ ld [%lo(in_trap_handler) + %l4], %l5
+ dec %l5
+ st %l5, [%lo(in_trap_handler) + %l4]
+
+ jmpl %l2, %g0 ! Restore old PC
+ rett %l3 ! Restore old nPC
+");
+
+/* Convert ch from a hex digit to an int */
+
+static int
+hex(ch)
+ 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 $<data>#<checksum> */
+
+static void
+getpacket(buffer)
+ char *buffer;
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ unsigned char ch;
+
+ do
+ {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = getDebugChar()) != '$') ;
+
+ checksum = 0;
+ xmitcsum = -1;
+
+ count = 0;
+
+ /* now, read until a # or end of buffer is found */
+ 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 0
+ /* Humans shouldn't have to figure out checksums to type to it. */
+ putDebugChar ('+');
+ return;
+#endif
+ if (checksum != xmitcsum)
+ 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(buffer)
+ unsigned char *buffer;
+{
+ unsigned char checksum;
+ int count;
+ unsigned char ch;
+
+ /* $<packet info>#<checksum>. */
+ do
+ {
+ putDebugChar('$');
+ checksum = 0;
+ count = 0;
+
+ while (ch = buffer[count])
+ {
+ if (! putDebugChar(ch))
+ return;
+ checksum += ch;
+ count += 1;
+ }
+
+ putDebugChar('#');
+ putDebugChar(hexchars[checksum >> 4]);
+ putDebugChar(hexchars[checksum & 0xf]);
+
+ }
+ while (getDebugChar() != '+');
+}
+
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
+/* Indicate to caller of mem2hex or hex2mem that there has been an
+ error. */
+static volatile int mem_err = 0;
+
+/* 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(mem, buf, count, may_fault)
+ unsigned char *mem;
+ unsigned char *buf;
+ int count;
+ int may_fault;
+{
+ unsigned char ch;
+
+ set_mem_fault_trap(may_fault);
+
+ while (count-- > 0)
+ {
+ ch = *mem++;
+ if (mem_err)
+ return 0;
+ *buf++ = hexchars[ch >> 4];
+ *buf++ = hexchars[ch & 0xf];
+ }
+
+ *buf = 0;
+
+ set_mem_fault_trap(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(buf, mem, count, may_fault)
+ unsigned char *buf;
+ unsigned char *mem;
+ int count;
+ int may_fault;
+{
+ int i;
+ unsigned char ch;
+
+ set_mem_fault_trap(may_fault);
+
+ for (i=0; i<count; i++)
+ {
+ ch = hex(*buf++) << 4;
+ ch |= hex(*buf++);
+ *mem++ = ch;
+ if (mem_err)
+ return 0;
+ }
+
+ set_mem_fault_trap(0);
+
+ 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 SPARClite */
+ unsigned char signo; /* Signal that we map this trap into */
+} hard_trap_info[] = {
+ {1, SIGSEGV}, /* instruction access error */
+ {2, SIGILL}, /* privileged instruction */
+ {3, SIGILL}, /* illegal instruction */
+ {4, SIGEMT}, /* fp disabled */
+ {36, SIGEMT}, /* cp disabled */
+ {7, SIGBUS}, /* mem address not aligned */
+ {9, SIGSEGV}, /* data access exception */
+ {10, SIGEMT}, /* tag overflow */
+ {128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */
+ {255, SIGTRAP}, /* hardware breakpoint */
+ {0, 0} /* Must be last */
+};
+
+/* Set up exception handlers for tracing and breakpoints */
+
+void
+set_debug_traps()
+{
+ struct hard_trap_info *ht;
+
+ for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+ exceptionHandler(ht->tt, trap_low);
+
+ /* In case GDB is started before us, ack any packets (presumably
+ "$?#xx") sitting there. */
+
+ putDebugChar ('+');
+
+ initialized = 1;
+}
+
+asm ("
+! Trap handler for memory errors. This just sets mem_err to be non-zero. It
+! assumes that %l1 is non-zero. This should be safe, as it is doubtful that
+! 0 would ever contain code that could mem fault. This routine will skip
+! past the faulting instruction after setting mem_err.
+
+ .text
+ .align 4
+
+_fltr_set_mem_err:
+ sethi %hi(_mem_err), %l0
+ st %l1, [%l0 + %lo(_mem_err)]
+ jmpl %l2, %g0
+ rett %l2+4
+");
+
+static void
+set_mem_fault_trap(enable)
+ int enable;
+{
+ extern void fltr_set_mem_err();
+ mem_err = 0;
+
+ if (enable)
+ exceptionHandler(9, fltr_set_mem_err);
+ else
+ exceptionHandler(9, trap_low);
+}
+
+asm ("
+ .text
+ .align 4
+
+_dummy_hw_breakpoint:
+ jmpl %l2, %g0
+ rett %l2+4
+ nop
+ nop
+");
+
+static void
+set_hw_breakpoint_trap(enable)
+ int enable;
+{
+ extern void dummy_hw_breakpoint();
+
+ if (enable)
+ exceptionHandler(255, dummy_hw_breakpoint);
+ else
+ exceptionHandler(255, trap_low);
+}
+
+static void
+get_in_break_mode()
+{
+ set_hw_breakpoint_trap(1);
+
+ asm("
+ sethi %hi(0xff10), %l4
+ or %l4, %lo(0xff10), %l4
+ sta %g0, [%l4]0x1
+ nop
+ nop
+ nop
+ ");
+
+ set_hw_breakpoint_trap(0);
+}
+
+/* Convert the SPARC hardware trap type code to a unix signal number. */
+
+static int
+computeSignal(tt)
+ 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 function does all command procesing for interfacing to gdb. It
+ * returns 1 if you should skip the instruction at the trap address, 0
+ * otherwise.
+ */
+
+
+static void
+handle_exception (registers)
+ unsigned long *registers;
+{
+ int tt; /* Trap type */
+ int sigval;
+ int addr;
+ int length;
+ char *ptr;
+ unsigned long *sp;
+ unsigned long dsr;
+
+/* First, we must force all of the windows to be spilled out */
+
+ asm(" save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ save %sp, -64, %sp
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+ restore
+");
+
+ if (registers[PC] == (unsigned long)breakinst)
+ {
+ registers[PC] = registers[NPC];
+ registers[NPC] += 4;
+ }
+ sp = (unsigned long *)registers[SP];
+
+ dsr = (unsigned long)registers[DSR];
+ if (dsr & 0x3c)
+ {
+ tt = 255;
+ }
+ else
+ {
+ tt = (registers[TBR] >> 4) & 0xff;
+ }
+
+ /* reply to host that an exception has occurred */
+ sigval = computeSignal(tt);
+ ptr = remcomOutBuffer;
+
+ *ptr++ = 'T';
+ *ptr++ = hexchars[sigval >> 4];
+ *ptr++ = hexchars[sigval & 0xf];
+
+ *ptr++ = hexchars[PC >> 4];
+ *ptr++ = hexchars[PC & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)®isters[PC], ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[FP >> 4];
+ *ptr++ = hexchars[FP & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[SP >> 4];
+ *ptr++ = hexchars[SP & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&sp, ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[NPC >> 4];
+ *ptr++ = hexchars[NPC & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)®isters[NPC], ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[O7 >> 4];
+ *ptr++ = hexchars[O7 & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)®isters[O7], ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = 0;
+
+ putpacket(remcomOutBuffer);
+
+ while (1)
+ {
+ remcomOutBuffer[0] = 0;
+
+ getpacket(remcomInBuffer);
+ switch (remcomInBuffer[0])
+ {
+ case '?':
+ remcomOutBuffer[0] = 'S';
+ remcomOutBuffer[1] = hexchars[sigval >> 4];
+ remcomOutBuffer[2] = hexchars[sigval & 0xf];
+ remcomOutBuffer[3] = 0;
+ break;
+
+ case 'd':
+ /* toggle debug flag */
+ break;
+
+ case 'g': /* return the value of the CPU registers */
+ {
+ ptr = remcomOutBuffer;
+ ptr = mem2hex((char *)registers, ptr, 16 * 4, 0); /* G & O regs */
+ ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */
+ memset(ptr, '0', 32 * 8); /* Floating point */
+ ptr = mem2hex((char *)®isters[Y],
+ ptr + 32 * 4 * 2,
+ 8 * 4,
+ 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ mem2hex((char *)®isters[DIA1], ptr,
+ 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */
+ }
+ break;
+
+ case 'G': /* set the value of the CPU registers - return OK */
+ {
+ unsigned long *newsp, psr;
+
+ psr = registers[PSR];
+
+ ptr = &remcomInBuffer[1];
+ hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */
+ hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */
+ hex2mem(ptr + 64 * 4 * 2, (char *)®isters[Y],
+ 8 * 4, 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ hex2mem(ptr + 72 * 4 * 2, (char *)®isters[DIA1],
+ 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */
+
+ /* See if the stack pointer has moved. If so, then copy the saved
+ locals and ins to the new location. This keeps the window
+ overflow and underflow routines happy. */
+
+ newsp = (unsigned long *)registers[SP];
+ if (sp != newsp)
+ sp = memcpy(newsp, sp, 16 * 4);
+
+ /* Don't allow CWP to be modified. */
+
+ if (psr != registers[PSR])
+ registers[PSR] = (psr & 0x1f) | (registers[PSR] & ~0x1f);
+
+ strcpy(remcomOutBuffer,"OK");
+ }
+ break;
+
+ case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
+ /* Try to read %x,%x. */
+
+ ptr = &remcomInBuffer[1];
+
+ if (hexToInt(&ptr, &addr)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length))
+ {
+ if (mem2hex((char *)addr, remcomOutBuffer, length, 1))
+ break;
+
+ strcpy (remcomOutBuffer, "E03");
+ }
+ else
+ strcpy(remcomOutBuffer,"E01");
+ break;
+
+ case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
+ /* Try to read '%x,%x:'. */
+
+ ptr = &remcomInBuffer[1];
+
+ if (hexToInt(&ptr, &addr)
+ && *ptr++ == ','
+ && hexToInt(&ptr, &length)
+ && *ptr++ == ':')
+ {
+ if (hex2mem(ptr, (char *)addr, length, 1))
+ strcpy(remcomOutBuffer, "OK");
+ else
+ strcpy(remcomOutBuffer, "E03");
+ }
+ else
+ strcpy(remcomOutBuffer, "E02");
+ break;
+
+ case 'c': /* cAA..AA Continue at address AA..AA(optional) */
+ /* try to read optional parameter, pc unchanged if no parm */
+
+ ptr = &remcomInBuffer[1];
+ if (hexToInt(&ptr, &addr))
+ {
+ registers[PC] = addr;
+ registers[NPC] = addr + 4;
+ }
+
+/* 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.
+ */
+
+ flush_i_cache();
+ return;
+
+ /* kill the program */
+ case 'k' : /* do nothing */
+ break;
+#if 0
+ case 't': /* Test feature */
+ asm (" std %f30,[%sp]");
+ break;
+#endif
+ case 'r': /* Reset */
+ asm ("call 0
+ nop ");
+ break;
+
+#if 0
+Disabled until we can unscrew this properly
+
+ case 'b': /* bBB... Set baud rate to BB... */
+ {
+ int baudrate;
+ extern void set_timer_3();
+
+ ptr = &remcomInBuffer[1];
+ if (!hexToInt(&ptr, &baudrate))
+ {
+ strcpy(remcomOutBuffer,"B01");
+ break;
+ }
+
+ /* Convert baud rate to uart clock divider */
+ switch (baudrate)
+ {
+ case 38400:
+ baudrate = 16;
+ break;
+ case 19200:
+ baudrate = 33;
+ break;
+ case 9600:
+ baudrate = 65;
+ break;
+ default:
+ strcpy(remcomOutBuffer,"B02");
+ goto x1;
+ }
+
+ putpacket("OK"); /* Ack before changing speed */
+ set_timer_3(baudrate); /* Set it */
+ }
+x1: break;
+#endif
+ } /* switch */
+
+ /* reply to the request */
+ putpacket(remcomOutBuffer);
+ }
+}
+
+/* This function will generate a breakpoint exception. It is used at the
+ beginning of a program to sync up with a debugger and can be used
+ otherwise as a quick means to stop program execution and "break" into
+ the debugger. */
+
+void
+breakpoint()
+{
+ if (!initialized)
+ return;
+
+ asm(" .globl _breakinst
+
+ _breakinst: ta 1
+ ");
+}
+
+static void
+hw_breakpoint()
+{
+ asm("
+ ta 127
+ ");
+}
--- /dev/null
+/* Target-dependent code for the Fujitsu SPARCLITE for GDB, the GNU debugger.
+ Copyright 1994 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "defs.h"
+#include "gdbcore.h"
+#include "breakpoint.h"
+
+#define DDA2_SUP_ASI 0xb000000
+#define DDA1_SUP_ASI 0xb0000
+
+#define DDA2_ASI_MASK 0xff000000
+#define DDA1_ASI_MASK 0xff0000
+#define DIA2_SUP_MODE 0x8000
+#define DIA1_SUP_MODE 0x4000
+#define DDA2_ENABLE 0x100
+#define DDA1_ENABLE 0x80
+#define DIA2_ENABLE 0x40
+#define DIA1_ENABLE 0x20
+#define DSINGLE_STEP 0x10
+#define DDV_TYPE_MASK 0xc
+#define DDV_TYPE_LOAD 0x0
+#define DDV_TYPE_STORE 0x4
+#define DDV_TYPE_ACCESS 0x8
+#define DDV_TYPE_ALWAYS 0xc
+#define DDV_COND 0x2
+#define DDV_MASK 0x1
+
+int
+sparclite_insert_watchpoint(addr, len, type)
+ CORE_ADDR addr;
+ int len;
+ int type;
+{
+CORE_ADDR dcr;
+
+ dcr = read_register (DCR_REGNUM);
+
+ if (!(dcr & DDA1_ENABLE))
+ {
+ write_register (DDA1_REGNUM, addr);
+ dcr &= ~(DDA1_ASI_MASK | DDV_TYPE_MASK);
+ dcr |= (DDA1_SUP_ASI | DDA1_ENABLE);
+ if (type == 1)
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_LOAD & (~DDV_COND & ~DDV_MASK));
+ }
+ else if (type == 0)
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_STORE & (~DDV_COND & ~DDV_MASK));
+ }
+ else
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_ACCESS);
+ }
+ write_register (DCR_REGNUM, dcr);
+ }
+ else if (!(dcr & DDA2_ENABLE))
+ {
+ write_register (DDA2_REGNUM, addr);
+ dcr &= ~(DDA2_ASI_MASK & DDV_TYPE_MASK);
+ dcr |= (DDA2_SUP_ASI | DDA2_ENABLE);
+ if (type == 1)
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_LOAD & ~DDV_COND & ~DDV_MASK);
+ }
+ else if (type == 0)
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_STORE & ~DDV_COND & ~DDV_MASK);
+ }
+ else
+ {
+ write_register (DDV1_REGNUM, 0);
+ write_register (DDV2_REGNUM, 0xffffffff);
+ dcr |= (DDV_TYPE_ACCESS);
+ }
+ write_register (DCR_REGNUM, dcr);
+ }
+ else
+ return -1;
+
+ return 0;
+}
+
+int
+sparclite_remove_watchpoint(addr, len, type)
+ CORE_ADDR addr;
+ int len;
+ int type;
+{
+CORE_ADDR dcr, dda1, dda2;
+
+ dcr = read_register (DCR_REGNUM);
+ dda1 = read_register (DDA1_REGNUM);
+ dda2 = read_register (DDA2_REGNUM);
+
+ if ((dcr & DDA1_ENABLE) && addr == dda1) {
+ write_register (DCR_REGNUM, (dcr & ~DDA1_ENABLE));
+ }
+ else if ((dcr & DDA2_ENABLE) && addr == dda2) {
+ write_register (DCR_REGNUM, (dcr & ~DDA2_ENABLE));
+ }
+ else
+ return -1;
+
+ return 0;
+}
+
+int
+sparclite_insert_hw_breakpoint(addr, len)
+ CORE_ADDR addr;
+ int len;
+{
+CORE_ADDR dcr;
+
+ dcr = read_register (DCR_REGNUM);
+
+ if (!(dcr & DIA1_ENABLE)) {
+ write_register (DIA1_REGNUM, addr);
+ write_register (DCR_REGNUM, (dcr | DIA1_ENABLE | DIA1_SUP_MODE));
+ }
+ else if (!(dcr & DIA2_ENABLE)) {
+ write_register (DIA2_REGNUM, addr);
+ write_register (DCR_REGNUM, (dcr | DIA2_ENABLE | DIA2_SUP_MODE));
+ }
+ else
+ return -1;
+
+ return 0;
+}
+
+int
+sparclite_remove_hw_breakpoint(addr, shadow)
+ CORE_ADDR addr;
+ int shadow;
+{
+CORE_ADDR dcr, dia1, dia2;
+
+ dcr = read_register (DCR_REGNUM);
+ dia1 = read_register (DIA1_REGNUM);
+ dia2 = read_register (DIA2_REGNUM);
+
+ if ((dcr & DIA1_ENABLE) && addr == dia1) {
+ write_register (DCR_REGNUM, (dcr & ~DIA1_ENABLE));
+ }
+ else if ((dcr & DIA2_ENABLE) && addr == dia2) {
+ write_register (DCR_REGNUM, (dcr & ~DIA2_ENABLE));
+ }
+ else
+ return -1;
+
+ return 0;
+}
+
+int
+sparclite_check_watch_resources(type, cnt, ot)
+ int type;
+ int cnt;
+ int ot;
+{
+ if (type == bp_hardware_breakpoint) {
+ if (TARGET_HW_BREAK_LIMIT == 0) return 0;
+ else if (cnt <= TARGET_HW_BREAK_LIMIT) return 1;
+ }
+ else {
+ if (TARGET_HW_WATCH_LIMIT == 0) return 0;
+ else if (ot) return -1;
+ else if (cnt <= TARGET_HW_WATCH_LIMIT) return 1;
+ }
+ return -1;
+}
+
+CORE_ADDR
+sparclite_stopped_data_address()
+{
+ CORE_ADDR dsr, dda1, dda2;
+
+ dsr = read_register (DSR_REGNUM);
+ dda1 = read_register (DDA1_REGNUM);
+ dda2 = read_register (DDA2_REGNUM);
+
+ if (dsr & 0x10) return dda1;
+ else if (dsr & 0x20) return dda2;
+ else return 0;
+}
-/****************************************************************************
-
- THIS SOFTWARE IS NOT COPYRIGHTED
-
- HP offers the following for use in the public domain. HP makes no
- warranty with regard to the software or it's performance and the
- user accepts the software "AS IS" with all faults.
-
- HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD
- TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES
- OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
-
-****************************************************************************/
-
-/****************************************************************************
- * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $
- *
- * Module name: remcom.c $
- * Revision: 1.34 $
- * Date: 91/03/09 12:29:49 $
- * Contributor: Lake Stevens Instrument Division$
- *
- * Description: low level support for gdb debugger. $
- *
- * Considerations: only works on target hardware $
- *
- * Written by: Glenn Engel $
- * ModuleState: Experimental $
- *
- * NOTES: See Below $
- *
- * Modified for SPARC by Stu Grossman, Cygnus Support.
- * Based on sparc-stub.c, it's modified for SPARClite Debug Unit hardware
- * breakpoint support to create sparclite-stub.c, by Kung Hsu, Cygnus Support.
- *
- * This code has been extensively tested on the Fujitsu SPARClite demo board.
- *
- * To enable debugger support, two things need to happen. One, a
- * call to set_debug_traps() 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(). Breakpoint()
- * simulates a breakpoint by executing a trap #1.
- *
- *************
- *
- * 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 "defs.h"
-#include <string.h>
-#include <signal.h>
-
-/************************************************************************
- *
- * external low-level support routines
- */
-
-extern putDebugChar(); /* write a single character */
-extern getDebugChar(); /* read and return a single char */
-
-/************************************************************************/
-/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
-/* at least NUMREGBYTES*2 are needed for register packets */
-#define BUFMAX 2048
-
-static int initialized = 0; /* !0 means we've been initialized */
-
-extern void breakinst();
-static void hw_breakpoint();
-static void set_mem_fault_trap();
-static void get_in_break_mode();
-
-static const char hexchars[]="0123456789abcdef";
-
-#define NUMREGS 80
-
-/* Number of bytes of registers. */
-#define NUMREGBYTES (NUMREGS * 4)
-enum regnames {G0, G1, G2, G3, G4, G5, G6, G7,
- O0, O1, O2, O3, O4, O5, SP, O7,
- L0, L1, L2, L3, L4, L5, L6, L7,
- I0, I1, I2, I3, I4, I5, FP, I7,
-
- F0, F1, F2, F3, F4, F5, F6, F7,
- F8, F9, F10, F11, F12, F13, F14, F15,
- F16, F17, F18, F19, F20, F21, F22, F23,
- F24, F25, F26, F27, F28, F29, F30, F31,
- Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR,
- DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR };
-
-/*************************** ASSEMBLY CODE MACROS *************************/
-/* */
-
-extern void trap_low();
-
-asm("
- .reserve trapstack, 1000 * 4, \"bss\", 8
-
- .data
- .align 4
-
-in_trap_handler:
- .word 0
-
- .text
- .align 4
-
-! This function is called when any SPARC trap (except window overflow or
-! underflow) occurs. It makes sure that the invalid register window is still
-! available before jumping into C code. It will also restore the world if you
-! return from handle_exception.
-
- .globl _trap_low
-_trap_low:
- mov %psr, %l0
- mov %wim, %l3
-
- srl %l3, %l0, %l4 ! wim >> cwp
- cmp %l4, 1
- bne window_fine ! Branch if not in the invalid window
- nop
-
-! Handle window overflow
-
- mov %g1, %l4 ! Save g1, we use it to hold the wim
- srl %l3, 1, %g1 ! Rotate wim right
- tst %g1
- bg good_wim ! Branch if new wim is non-zero
-
-! At this point, we need to bring a 1 into the high order bit of the wim.
-! Since we don't want to make any assumptions about the number of register
-! windows, we figure it out dynamically so as to setup the wim correctly.
-
- not %g1 ! Fill g1 with ones
- mov %g1, %wim ! Fill the wim with ones
- nop
- nop
- nop
- mov %wim, %g1 ! Read back the wim
- inc %g1 ! Now g1 has 1 just to left of wim
- srl %g1, 1, %g1 ! Now put 1 at top of wim
- mov %g0, %wim ! Clear wim so that subsequent save
- nop ! won't trap
- nop
- nop
-
-good_wim:
- save %g0, %g0, %g0 ! Slip into next window
- mov %g1, %wim ! Install the new wim
-
- std %l0, [%sp + 0 * 4] ! save L & I registers
- std %l2, [%sp + 2 * 4]
- std %l4, [%sp + 4 * 4]
- std %l6, [%sp + 6 * 4]
-
- std %i0, [%sp + 8 * 4]
- std %i2, [%sp + 10 * 4]
- std %i4, [%sp + 12 * 4]
- std %i6, [%sp + 14 * 4]
-
- restore ! Go back to trap window.
- mov %l4, %g1 ! Restore %g1
-
-window_fine:
- sethi %hi(in_trap_handler), %l4
- ld [%lo(in_trap_handler) + %l4], %l5
- tst %l5
- bg recursive_trap
- inc %l5
-
- set trapstack+1000*4, %sp ! Switch to trap stack
-
-recursive_trap:
- st %l5, [%lo(in_trap_handler) + %l4]
- sub %sp,(16+1+6+1+80)*4,%sp ! Make room for input & locals
- ! + hidden arg + arg spill
- ! + doubleword alignment
- ! + registers[72] local var
-
- std %g0, [%sp + (24 + 0) * 4] ! registers[Gx]
- std %g2, [%sp + (24 + 2) * 4]
- std %g4, [%sp + (24 + 4) * 4]
- std %g6, [%sp + (24 + 6) * 4]
-
- std %i0, [%sp + (24 + 8) * 4] ! registers[Ox]
- std %i2, [%sp + (24 + 10) * 4]
- std %i4, [%sp + (24 + 12) * 4]
- std %i6, [%sp + (24 + 14) * 4]
- ! F0->F31 not implemented
- mov %y, %l4
- mov %tbr, %l5
- st %l4, [%sp + (24 + 64) * 4] ! Y
- st %l0, [%sp + (24 + 65) * 4] ! PSR
- st %l3, [%sp + (24 + 66) * 4] ! WIM
- st %l5, [%sp + (24 + 67) * 4] ! TBR
- st %l1, [%sp + (24 + 68) * 4] ! PC
- st %l2, [%sp + (24 + 69) * 4] ! NPC
- ! CPSR and FPSR not impl
- or %l0, 0xf20, %l4
- mov %l4, %psr ! Turn on traps, disable interrupts
- nop
- nop
- nop
- call _get_in_break_mode
- nop
- nop
- nop
-
- sethi %hi(0xff00), %l5
- or %l5, %lo(0xff00), %l5
-
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 72) * 4] ! DIA1, debug instr addr 1
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 73) * 4] ! DIA2, debug instr addr 2
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 74) * 4] ! DDA1, debug data addr 1
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 75) * 4] ! DDA2, debug data addr 2
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 76) * 4] ! DDV1, debug data val 1
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 77) * 4] ! DDV2, debug data val 2
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 78) * 4] ! DCR, debug control reg
- add %l5, 4, %l5
- lda [%l5]0x1, %l4
- st %l4, [%sp + (24 + 79) * 4] ! DSR, debug status reg
- nop
- nop
- or %l0, 0xf20, %l4
- mov %l4, %psr ! Turn on traps, disable interrupts
- nop
- nop
- nop
- call _handle_exception
- add %sp, 24 * 4, %o0 ! Pass address of registers
-
-! Reload all of the registers that aren't on the stack
-
- ld [%sp + (24 + 1) * 4], %g1 ! registers[Gx]
- ldd [%sp + (24 + 2) * 4], %g2
- ldd [%sp + (24 + 4) * 4], %g4
- ldd [%sp + (24 + 6) * 4], %g6
-
- ldd [%sp + (24 + 8) * 4], %i0 ! registers[Ox]
- ldd [%sp + (24 + 10) * 4], %i2
- ldd [%sp + (24 + 12) * 4], %i4
- ldd [%sp + (24 + 14) * 4], %i6
-
- sethi %hi(0xff00), %l2
- or %l2, %lo(0xff00), %l2
- ldd [%sp + (24 + 72) * 4], %l4 ! DIA1, debug instr addr 1
- stda %l4, [%l2]0x1
- nop
- nop
- nop
- nop
- ldd [%sp + (24 + 74) * 4], %l4 ! DDA1, debug data addr 1
- add %l2, 8, %l2
- stda %l4, [%l2]0x1
- nop
- nop
- nop
- nop
- ldd [%sp + (24 + 76) * 4], %l4 ! DDV1, debug data value 1
- add %l2, 8, %l2
- stda %l4, [%l2]0x1
- nop
- nop
- nop
- nop
- ld [%sp + (24 + 78) * 4], %l4 ! DCR, debug control reg
- ld [%sp + (24 + 79) * 4], %l5 ! DSR, debug control reg
- add %l2, 8, %l2
- or %l4, 0x200, %l4
- sta %l4, [%l2]0x1
- add %l2, 4, %l2
- sta %l5, [%l2]0x1
- nop
- nop
- nop
- nop
-
- ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR
- ldd [%sp + (24 + 68) * 4], %l2 ! PC & NPC
-
- restore ! Ensure that previous window is valid
- save %g0, %g0, %g0 ! by causing a window_underflow trap
-
- mov %l0, %y
- mov %l1, %psr ! Make sure that traps are disabled
- ! for rett
- sethi %hi(in_trap_handler), %l4
- ld [%lo(in_trap_handler) + %l4], %l5
- dec %l5
- st %l5, [%lo(in_trap_handler) + %l4]
-
- jmpl %l2, %g0 ! Restore old PC
- rett %l3 ! Restore old nPC
-");
-
-/* Convert ch from a hex digit to an int */
-
-static int
-hex(ch)
- 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 $<data>#<checksum> */
-
-static void
-getpacket(buffer)
- char *buffer;
-{
- unsigned char checksum;
- unsigned char xmitcsum;
- int i;
- int count;
- unsigned char ch;
-
- do
- {
- /* wait around for the start character, ignore all other characters */
- while ((ch = getDebugChar()) != '$') ;
-
- checksum = 0;
- xmitcsum = -1;
-
- count = 0;
-
- /* now, read until a # or end of buffer is found */
- 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 0
- /* Humans shouldn't have to figure out checksums to type to it. */
- putDebugChar ('+');
- return;
-#endif
- if (checksum != xmitcsum)
- 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(buffer)
- unsigned char *buffer;
-{
- unsigned char checksum;
- int count;
- unsigned char ch;
-
- /* $<packet info>#<checksum>. */
- do
- {
- putDebugChar('$');
- checksum = 0;
- count = 0;
-
- while (ch = buffer[count])
- {
- if (! putDebugChar(ch))
- return;
- checksum += ch;
- count += 1;
- }
-
- putDebugChar('#');
- putDebugChar(hexchars[checksum >> 4]);
- putDebugChar(hexchars[checksum & 0xf]);
-
- }
- while (getDebugChar() != '+');
-}
-
-static char remcomInBuffer[BUFMAX];
-static char remcomOutBuffer[BUFMAX];
-
-/* Indicate to caller of mem2hex or hex2mem that there has been an
- error. */
-static volatile int mem_err = 0;
-
-/* 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(mem, buf, count, may_fault)
- unsigned char *mem;
- unsigned char *buf;
- int count;
- int may_fault;
-{
- unsigned char ch;
-
- set_mem_fault_trap(may_fault);
-
- while (count-- > 0)
- {
- ch = *mem++;
- if (mem_err)
- return 0;
- *buf++ = hexchars[ch >> 4];
- *buf++ = hexchars[ch & 0xf];
- }
-
- *buf = 0;
-
- set_mem_fault_trap(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(buf, mem, count, may_fault)
- unsigned char *buf;
- unsigned char *mem;
- int count;
- int may_fault;
-{
- int i;
- unsigned char ch;
-
- set_mem_fault_trap(may_fault);
-
- for (i=0; i<count; i++)
- {
- ch = hex(*buf++) << 4;
- ch |= hex(*buf++);
- *mem++ = ch;
- if (mem_err)
- return 0;
- }
-
- set_mem_fault_trap(0);
-
- 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 SPARClite */
- unsigned char signo; /* Signal that we map this trap into */
-} hard_trap_info[] = {
- {1, SIGSEGV}, /* instruction access error */
- {2, SIGILL}, /* privileged instruction */
- {3, SIGILL}, /* illegal instruction */
- {4, SIGEMT}, /* fp disabled */
- {36, SIGEMT}, /* cp disabled */
- {7, SIGBUS}, /* mem address not aligned */
- {9, SIGSEGV}, /* data access exception */
- {10, SIGEMT}, /* tag overflow */
- {128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */
- {255, SIGTRAP}, /* hardware breakpoint */
- {0, 0} /* Must be last */
-};
-
-/* Set up exception handlers for tracing and breakpoints */
-
-void
-set_debug_traps()
-{
- struct hard_trap_info *ht;
-
- for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
- exceptionHandler(ht->tt, trap_low);
-
- /* In case GDB is started before us, ack any packets (presumably
- "$?#xx") sitting there. */
-
- putDebugChar ('+');
-
- initialized = 1;
-}
-
-asm ("
-! Trap handler for memory errors. This just sets mem_err to be non-zero. It
-! assumes that %l1 is non-zero. This should be safe, as it is doubtful that
-! 0 would ever contain code that could mem fault. This routine will skip
-! past the faulting instruction after setting mem_err.
-
- .text
- .align 4
-
-_fltr_set_mem_err:
- sethi %hi(_mem_err), %l0
- st %l1, [%l0 + %lo(_mem_err)]
- jmpl %l2, %g0
- rett %l2+4
-");
-
-static void
-set_mem_fault_trap(enable)
- int enable;
-{
- extern void fltr_set_mem_err();
- mem_err = 0;
-
- if (enable)
- exceptionHandler(9, fltr_set_mem_err);
- else
- exceptionHandler(9, trap_low);
-}
-
-asm ("
- .text
- .align 4
-
-_dummy_hw_breakpoint:
- jmpl %l2, %g0
- rett %l2+4
- nop
- nop
-");
-
-static void
-set_hw_breakpoint_trap(enable)
- int enable;
-{
- extern void dummy_hw_breakpoint();
-
- if (enable)
- exceptionHandler(255, dummy_hw_breakpoint);
- else
- exceptionHandler(255, trap_low);
-}
-
-static void
-get_in_break_mode()
-{
- set_hw_breakpoint_trap(1);
-
- asm("
- sethi %hi(0xff10), %l4
- or %l4, %lo(0xff10), %l4
- sta %g0, [%l4]0x1
- nop
- nop
- nop
- ");
-
- set_hw_breakpoint_trap(0);
-}
-
-/* Convert the SPARC hardware trap type code to a unix signal number. */
-
-static int
-computeSignal(tt)
- 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 function does all command procesing for interfacing to gdb. It
- * returns 1 if you should skip the instruction at the trap address, 0
- * otherwise.
- */
-
-
-static void
-handle_exception (registers)
- unsigned long *registers;
-{
- int tt; /* Trap type */
- int sigval;
- int addr;
- int length;
- char *ptr;
- unsigned long *sp;
- unsigned long dsr;
-
-/* First, we must force all of the windows to be spilled out */
-
- asm(" save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- save %sp, -64, %sp
- restore
- restore
- restore
- restore
- restore
- restore
- restore
- restore
-");
-
- if (registers[PC] == (unsigned long)breakinst)
- {
- registers[PC] = registers[NPC];
- registers[NPC] += 4;
- }
- sp = (unsigned long *)registers[SP];
-
- dsr = (unsigned long)registers[DSR];
- if (dsr & 0x3c)
- {
- tt = 255;
- }
- else
- {
- tt = (registers[TBR] >> 4) & 0xff;
- }
-
- /* reply to host that an exception has occurred */
- sigval = computeSignal(tt);
- ptr = remcomOutBuffer;
-
- *ptr++ = 'T';
- *ptr++ = hexchars[sigval >> 4];
- *ptr++ = hexchars[sigval & 0xf];
-
- *ptr++ = hexchars[PC >> 4];
- *ptr++ = hexchars[PC & 0xf];
- *ptr++ = ':';
- ptr = mem2hex((char *)®isters[PC], ptr, 4, 0);
- *ptr++ = ';';
-
- *ptr++ = hexchars[FP >> 4];
- *ptr++ = hexchars[FP & 0xf];
- *ptr++ = ':';
- ptr = mem2hex(sp + 8 + 6, ptr, 4, 0); /* FP */
- *ptr++ = ';';
-
- *ptr++ = hexchars[SP >> 4];
- *ptr++ = hexchars[SP & 0xf];
- *ptr++ = ':';
- ptr = mem2hex((char *)&sp, ptr, 4, 0);
- *ptr++ = ';';
-
- *ptr++ = hexchars[NPC >> 4];
- *ptr++ = hexchars[NPC & 0xf];
- *ptr++ = ':';
- ptr = mem2hex((char *)®isters[NPC], ptr, 4, 0);
- *ptr++ = ';';
-
- *ptr++ = hexchars[O7 >> 4];
- *ptr++ = hexchars[O7 & 0xf];
- *ptr++ = ':';
- ptr = mem2hex((char *)®isters[O7], ptr, 4, 0);
- *ptr++ = ';';
-
- *ptr++ = 0;
-
- putpacket(remcomOutBuffer);
-
- while (1)
- {
- remcomOutBuffer[0] = 0;
-
- getpacket(remcomInBuffer);
- switch (remcomInBuffer[0])
- {
- case '?':
- remcomOutBuffer[0] = 'S';
- remcomOutBuffer[1] = hexchars[sigval >> 4];
- remcomOutBuffer[2] = hexchars[sigval & 0xf];
- remcomOutBuffer[3] = 0;
- break;
-
- case 'd':
- /* toggle debug flag */
- break;
-
- case 'g': /* return the value of the CPU registers */
- {
- ptr = remcomOutBuffer;
- ptr = mem2hex((char *)registers, ptr, 16 * 4, 0); /* G & O regs */
- ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */
- memset(ptr, '0', 32 * 8); /* Floating point */
- ptr = mem2hex((char *)®isters[Y],
- ptr + 32 * 4 * 2,
- 8 * 4,
- 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
- mem2hex((char *)®isters[DIA1], ptr,
- 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */
- }
- break;
-
- case 'G': /* set the value of the CPU registers - return OK */
- {
- unsigned long *newsp, psr;
-
- psr = registers[PSR];
-
- ptr = &remcomInBuffer[1];
- hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */
- hex2mem(ptr + 16 * 4 * 2, sp + 0, 16 * 4, 0); /* L & I regs */
- hex2mem(ptr + 64 * 4 * 2, (char *)®isters[Y],
- 8 * 4, 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
- hex2mem(ptr + 72 * 4 * 2, (char *)®isters[DIA1],
- 8 * 4, 0); /* DIA1, DIA2, DDA1, DDA2, DDV1, DDV2, DCR, DSR */
-
- /* See if the stack pointer has moved. If so, then copy the saved
- locals and ins to the new location. This keeps the window
- overflow and underflow routines happy. */
-
- newsp = (unsigned long *)registers[SP];
- if (sp != newsp)
- sp = memcpy(newsp, sp, 16 * 4);
-
- /* Don't allow CWP to be modified. */
-
- if (psr != registers[PSR])
- registers[PSR] = (psr & 0x1f) | (registers[PSR] & ~0x1f);
-
- strcpy(remcomOutBuffer,"OK");
- }
- break;
-
- case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
- /* Try to read %x,%x. */
-
- ptr = &remcomInBuffer[1];
-
- if (hexToInt(&ptr, &addr)
- && *ptr++ == ','
- && hexToInt(&ptr, &length))
- {
- if (mem2hex((char *)addr, remcomOutBuffer, length, 1))
- break;
-
- strcpy (remcomOutBuffer, "E03");
- }
- else
- strcpy(remcomOutBuffer,"E01");
- break;
-
- case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA return OK */
- /* Try to read '%x,%x:'. */
-
- ptr = &remcomInBuffer[1];
-
- if (hexToInt(&ptr, &addr)
- && *ptr++ == ','
- && hexToInt(&ptr, &length)
- && *ptr++ == ':')
- {
- if (hex2mem(ptr, (char *)addr, length, 1))
- strcpy(remcomOutBuffer, "OK");
- else
- strcpy(remcomOutBuffer, "E03");
- }
- else
- strcpy(remcomOutBuffer, "E02");
- break;
-
- case 'c': /* cAA..AA Continue at address AA..AA(optional) */
- /* try to read optional parameter, pc unchanged if no parm */
-
- ptr = &remcomInBuffer[1];
- if (hexToInt(&ptr, &addr))
- {
- registers[PC] = addr;
- registers[NPC] = addr + 4;
- }
-
-/* 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.
- */
-
- flush_i_cache();
- return;
-
- /* kill the program */
- case 'k' : /* do nothing */
- break;
-#if 0
- case 't': /* Test feature */
- asm (" std %f30,[%sp]");
- break;
-#endif
- case 'r': /* Reset */
- asm ("call 0
- nop ");
- break;
-
-#if 0
-Disabled until we can unscrew this properly
-
- case 'b': /* bBB... Set baud rate to BB... */
- {
- int baudrate;
- extern void set_timer_3();
-
- ptr = &remcomInBuffer[1];
- if (!hexToInt(&ptr, &baudrate))
- {
- strcpy(remcomOutBuffer,"B01");
- break;
- }
-
- /* Convert baud rate to uart clock divider */
- switch (baudrate)
- {
- case 38400:
- baudrate = 16;
- break;
- case 19200:
- baudrate = 33;
- break;
- case 9600:
- baudrate = 65;
- break;
- default:
- strcpy(remcomOutBuffer,"B02");
- goto x1;
- }
-
- putpacket("OK"); /* Ack before changing speed */
- set_timer_3(baudrate); /* Set it */
- }
-x1: break;
-#endif
- } /* switch */
-
- /* reply to the request */
- putpacket(remcomOutBuffer);
- }
-}
-
-/* This function will generate a breakpoint exception. It is used at the
- beginning of a program to sync up with a debugger and can be used
- otherwise as a quick means to stop program execution and "break" into
- the debugger. */
-
-void
-breakpoint()
-{
- if (!initialized)
- return;
-
- asm(" .globl _breakinst
-
- _breakinst: ta 1
- ");
-}
-
-static void
-hw_breakpoint()
-{
- asm("
- ta 127
- ");
-}
-/* Target-dependent code for the Fujitsu SPARCLITE for GDB, the GNU debugger.
- Copyright 1994 Free Software Foundation, Inc.
-
-This file is part of GDB.
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
-
-#include "defs.h"
-#include "gdbcore.h"
-#include "breakpoint.h"
-
-#define DDA2_SUP_ASI 0xb000000
-#define DDA1_SUP_ASI 0xb0000
-
-#define DDA2_ASI_MASK 0xff000000
-#define DDA1_ASI_MASK 0xff0000
-#define DIA2_SUP_MODE 0x8000
-#define DIA1_SUP_MODE 0x4000
-#define DDA2_ENABLE 0x100
-#define DDA1_ENABLE 0x80
-#define DIA2_ENABLE 0x40
-#define DIA1_ENABLE 0x20
-#define DSINGLE_STEP 0x10
-#define DDV_TYPE_MASK 0xc
-#define DDV_TYPE_LOAD 0x0
-#define DDV_TYPE_STORE 0x4
-#define DDV_TYPE_ACCESS 0x8
-#define DDV_TYPE_ALWAYS 0xc
-#define DDV_COND 0x2
-#define DDV_MASK 0x1
-
-int
-sparclite_insert_watchpoint(addr, len, type)
- CORE_ADDR addr;
- int len;
- int type;
-{
-CORE_ADDR dcr;
-
- dcr = read_register (DCR_REGNUM);
-
- if (!(dcr & DDA1_ENABLE))
- {
- write_register (DDA1_REGNUM, addr);
- dcr &= ~(DDA1_ASI_MASK | DDV_TYPE_MASK);
- dcr |= (DDA1_SUP_ASI | DDA1_ENABLE);
- if (type == 1)
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_LOAD & (~DDV_COND & ~DDV_MASK));
- }
- else if (type == 0)
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_STORE & (~DDV_COND & ~DDV_MASK));
- }
- else
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_ACCESS);
- }
- write_register (DCR_REGNUM, dcr);
- }
- else if (!(dcr & DDA2_ENABLE))
- {
- write_register (DDA2_REGNUM, addr);
- dcr &= ~(DDA2_ASI_MASK & DDV_TYPE_MASK);
- dcr |= (DDA2_SUP_ASI | DDA2_ENABLE);
- if (type == 1)
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_LOAD & ~DDV_COND & ~DDV_MASK);
- }
- else if (type == 0)
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_STORE & ~DDV_COND & ~DDV_MASK);
- }
- else
- {
- write_register (DDV1_REGNUM, 0);
- write_register (DDV2_REGNUM, 0xffffffff);
- dcr |= (DDV_TYPE_ACCESS);
- }
- write_register (DCR_REGNUM, dcr);
- }
- else
- return -1;
-
- return 0;
-}
-
-int
-sparclite_remove_watchpoint(addr, len, type)
- CORE_ADDR addr;
- int len;
- int type;
-{
-CORE_ADDR dcr, dda1, dda2;
-
- dcr = read_register (DCR_REGNUM);
- dda1 = read_register (DDA1_REGNUM);
- dda2 = read_register (DDA2_REGNUM);
-
- if ((dcr & DDA1_ENABLE) && addr == dda1) {
- write_register (DCR_REGNUM, (dcr & ~DDA1_ENABLE));
- }
- else if ((dcr & DDA2_ENABLE) && addr == dda2) {
- write_register (DCR_REGNUM, (dcr & ~DDA2_ENABLE));
- }
- else
- return -1;
-
- return 0;
-}
-
-int
-sparclite_insert_hw_breakpoint(addr, len)
- CORE_ADDR addr;
- int len;
-{
-CORE_ADDR dcr;
-
- dcr = read_register (DCR_REGNUM);
-
- if (!(dcr & DIA1_ENABLE)) {
- write_register (DIA1_REGNUM, addr);
- write_register (DCR_REGNUM, (dcr | DIA1_ENABLE | DIA1_SUP_MODE));
- }
- else if (!(dcr & DIA2_ENABLE)) {
- write_register (DIA2_REGNUM, addr);
- write_register (DCR_REGNUM, (dcr | DIA2_ENABLE | DIA2_SUP_MODE));
- }
- else
- return -1;
-
- return 0;
-}
-
-int
-sparclite_remove_hw_breakpoint(addr, shadow)
- CORE_ADDR addr;
- int shadow;
-{
-CORE_ADDR dcr, dia1, dia2;
-
- dcr = read_register (DCR_REGNUM);
- dia1 = read_register (DIA1_REGNUM);
- dia2 = read_register (DIA2_REGNUM);
-
- if ((dcr & DIA1_ENABLE) && addr == dia1) {
- write_register (DCR_REGNUM, (dcr & ~DIA1_ENABLE));
- }
- else if ((dcr & DIA2_ENABLE) && addr == dia2) {
- write_register (DCR_REGNUM, (dcr & ~DIA2_ENABLE));
- }
- else
- return -1;
-
- return 0;
-}
-
-int
-sparclite_check_watch_resources(type, cnt, ot)
- int type;
- int cnt;
- int ot;
-{
- if (type == bp_hardware_breakpoint) {
- if (TARGET_HW_BREAK_LIMIT == 0) return 0;
- else if (cnt <= TARGET_HW_BREAK_LIMIT) return 1;
- }
- else {
- if (TARGET_HW_WATCH_LIMIT == 0) return 0;
- else if (ot) return -1;
- else if (cnt <= TARGET_HW_WATCH_LIMIT) return 1;
- }
- return -1;
-}
-
-CORE_ADDR
-sparclite_stopped_data_address()
-{
- CORE_ADDR dsr, dda1, dda2;
-
- dsr = read_register (DSR_REGNUM);
- dda1 = read_register (DDA1_REGNUM);
- dda2 = read_register (DDA2_REGNUM);
-
- if (dsr & 0x10) return dda1;
- else if (dsr & 0x20) return dda2;
- else return 0;
-}