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+/****************************************************************************
+
+ 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
+ * P set the value of a single CPU register OK or P01 (???)
+ *
+ * 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 <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 */
+static int remote_debug = 0; /* turn on verbose debugging */
+
+extern void breakinst();
+void _cprint();
+static void hw_breakpoint();
+static void set_mem_fault_trap();
+static void get_in_break_mode();
+static unsigned char *mem2hex();
+
+static const char hexchars[]="0123456789abcdef";
+
+#define NUMREGS 121
+
+static unsigned long saved_stack_pointer;
+
+/* 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,
+ CCSR, CCPR, CCCRCR, CCOR, CCOBR, CCIBR, CCIR, UNUSED1,
+
+ ASR1, ASR15, ASR17, ASR18, ASR19, ASR20, ASR21, ASR22,
+ /* the following not actually implemented */
+ AWR0, AWR1, AWR2, AWR3, AWR4, AWR5, AWR6, AWR7,
+ AWR8, AWR9, AWR10, AWR11, AWR12, AWR13, AWR14, AWR15,
+ AWR16, AWR17, AWR18, AWR19, AWR20, AWR21, AWR22, AWR23,
+ AWR24, AWR25, AWR26, AWR27, AWR28, AWR29, AWR30, AWR31,
+ APSR
+};
+
+/*************************** 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.
+!
+! On entry, trap_low expects l1 and l2 to contain pc and npc respectivly.
+
+ .globl _trap_low
+_trap_low:
+ mov %psr, %l0
+ mov %wim, %l3
+
+ srl %l3, %l0, %l4 ! wim >> cwp
+ and %l4, 0xff, %l4 ! Mask off windows 28, 29
+ 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
+ and %g1, 0xff, %g1 ! Mask off windows 28, 29
+ tst %g1
+ bg good_wim ! Branch if new wim is non-zero
+ nop
+
+! 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.
+
+ ! The normal way doesn't work on the sparclet as register windows
+ ! 28 and 29 are special purpose windows.
+ !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 0x80, %g1 ! Hack for sparclet
+
+ ! This doesn't work on the sparclet.
+ !mov %g0, %wim ! Clear wim so that subsequent save
+ ! won't trap
+ andn %l3, 0xff, %l5 ! Clear wim but not windows 28, 29
+ mov %l5, %wim
+ nop
+ 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+88)*4,%sp ! Make room for input & locals
+ ! + hidden arg + arg spill
+ ! + doubleword alignment
+ ! + registers[121]
+
+ 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]
+
+ ! FP regs (sparclet doesn't have fpu)
+
+ 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
+
+! Save coprocessor state.
+! See SK/demo/hdlc_demo/ldc_swap_context.S.
+
+ mov %psr, %l0
+ sethi %hi(0x2000), %l5 ! EC bit in PSR
+ or %l5, %l0, %l5
+ mov %l5, %psr ! enable coprocessor
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+ crdcxt %ccsr, %l1 ! capture CCSR
+ mov 0x6, %l2
+ cwrcxt %l2, %ccsr ! set CCP state machine for CCFR
+ crdcxt %ccfr, %l2 ! capture CCOR
+ cwrcxt %l2, %ccfr ! tickle CCFR
+ crdcxt %ccfr, %l3 ! capture CCOBR
+ cwrcxt %l3, %ccfr ! tickle CCFR
+ crdcxt %ccfr, %l4 ! capture CCIBR
+ cwrcxt %l4, %ccfr ! tickle CCFR
+ crdcxt %ccfr, %l5 ! capture CCIR
+ cwrcxt %l5, %ccfr ! tickle CCFR
+ crdcxt %ccpr, %l6 ! capture CCPR
+ crdcxt %cccrcr, %l7 ! capture CCCRCR
+ st %l1, [%sp + (24 + 72) * 4] ! save CCSR
+ st %l2, [%sp + (24 + 75) * 4] ! save CCOR
+ st %l3, [%sp + (24 + 76) * 4] ! save CCOBR
+ st %l4, [%sp + (24 + 77) * 4] ! save CCIBR
+ st %l5, [%sp + (24 + 78) * 4] ! save CCIR
+ st %l6, [%sp + (24 + 73) * 4] ! save CCPR
+ st %l7, [%sp + (24 + 74) * 4] ! save CCCRCR
+ mov %l0, %psr ! restore original PSR
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+
+! End of saving coprocessor state.
+! Save asr regs
+
+! Part of this is silly -- we should not display ASR15 or ASR19 at all.
+
+ sethi %hi(0x01000000), %l6
+ st %l6, [%sp + (24 + 81) * 4] ! ASR15 == NOP
+ sethi %hi(0xdeadc0de), %l6
+ or %l6, %lo(0xdeadc0de), %l6
+ st %l6, [%sp + (24 + 84) * 4] ! ASR19 == DEADC0DE
+
+ rd %asr1, %l4
+ st %l4, [%sp + (24 + 80) * 4]
+! rd %asr15, %l4 ! must not read ASR15
+! st %l4, [%sp + (24 + 81) * 4] ! (illegal instr trap)
+ rd %asr17, %l4
+ st %l4, [%sp + (24 + 82) * 4]
+ rd %asr18, %l4
+ st %l4, [%sp + (24 + 83) * 4]
+! rd %asr19, %l4 ! must not read asr19
+! st %l4, [%sp + (24 + 84) * 4] ! (halts the CPU)
+ rd %asr20, %l4
+ st %l4, [%sp + (24 + 85) * 4]
+ rd %asr21, %l4
+ st %l4, [%sp + (24 + 86) * 4]
+ rd %asr22, %l4
+ st %l4, [%sp + (24 + 87) * 4]
+
+! End of saving asr regs
+
+ 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
+
+ ! FP regs (sparclet doesn't have fpu)
+
+! Update the coprocessor registers.
+! See SK/demo/hdlc_demo/ldc_swap_context.S.
+
+ mov %psr, %l0
+ sethi %hi(0x2000), %l5 ! EC bit in PSR
+ or %l5, %l0, %l5
+ mov %l5, %psr ! enable coprocessor
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+
+ mov 0x6, %l2
+ cwrcxt %l2, %ccsr ! set CCP state machine for CCFR
+
+ ld [%sp + (24 + 72) * 4], %l1 ! saved CCSR
+ ld [%sp + (24 + 75) * 4], %l2 ! saved CCOR
+ ld [%sp + (24 + 76) * 4], %l3 ! saved CCOBR
+ ld [%sp + (24 + 77) * 4], %l4 ! saved CCIBR
+ ld [%sp + (24 + 78) * 4], %l5 ! saved CCIR
+ ld [%sp + (24 + 73) * 4], %l6 ! saved CCPR
+ ld [%sp + (24 + 74) * 4], %l7 ! saved CCCRCR
+
+ cwrcxt %l2, %ccfr ! restore CCOR
+ cwrcxt %l3, %ccfr ! restore CCOBR
+ cwrcxt %l4, %ccfr ! restore CCIBR
+ cwrcxt %l5, %ccfr ! restore CCIR
+ cwrcxt %l6, %ccpr ! restore CCPR
+ cwrcxt %l7, %cccrcr ! restore CCCRCR
+ cwrcxt %l1, %ccsr ! restore CCSR
+
+ mov %l0, %psr ! restore PSR
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+
+! End of coprocessor handling stuff.
+! Update asr regs
+
+ ld [%sp + (24 + 80) * 4], %l4
+ wr %l4, %asr1
+! ld [%sp + (24 + 81) * 4], %l4 ! can't write asr15
+! wr %l4, %asr15
+ ld [%sp + (24 + 82) * 4], %l4
+ wr %l4, %asr17
+ ld [%sp + (24 + 83) * 4], %l4
+ wr %l4, %asr18
+! ld [%sp + (24 + 84) * 4], %l4 ! can't write asr19
+! wr %l4, %asr19
+! ld [%sp + (24 + 85) * 4], %l4 ! can't write asr20
+! wr %l4, %asr20
+! ld [%sp + (24 + 86) * 4], %l4 ! can't write asr21
+! wr %l4, %asr21
+ ld [%sp + (24 + 87) * 4], %l4
+ wr %l4, %asr22
+
+! End of restoring asr regs
+
+
+ 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
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+
+ 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 $<data>#<checksum> */
+
+static void
+getpacket(buffer)
+ char *buffer;
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int i;
+ int count;
+ unsigned char ch;
+
+ do
+ {
+ /* wait around for the start character, ignore all other characters */
+ while ((ch = (getDebugChar() & 0x7f)) != '$')
+ ;
+
+ 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;
+
+ if (ch == '#')
+ {
+ xmitcsum = hex(ch = getDebugChar() & 0x7f) << 4;
+ xmitcsum |= hex(ch = getDebugChar() & 0x7f);
+
+ 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() & 0x7f) != '+');
+}
+
+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 exception */
+ {0x3b, SIGSEGV}, /* instruction access error */
+ {2, SIGILL}, /* illegal instruction */
+ {3, SIGILL}, /* privileged instruction */
+ {4, SIGEMT}, /* fp disabled */
+ {0x24, SIGEMT}, /* cp disabled */
+ {7, SIGBUS}, /* mem address not aligned */
+ {0x29, SIGSEGV}, /* data access exception */
+ {10, SIGEMT}, /* tag overflow */
+ {128+1, SIGTRAP}, /* ta 1 - normal breakpoint instruction */
+ {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(0x29, fltr_set_mem_err);
+ else
+ exceptionHandler(0x29, 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()
+{
+#if 0
+ int x;
+ mesg("get_in_break_mode, sp = ");
+ phex(&x);
+#endif
+ 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("
+ ! Ugh. sparclet has broken save
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-64,%sp
+ !save %sp, -64, %sp
+ save
+ add %fp,-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];
+
+ 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 *)&registers[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 *)&registers[NPC], ptr, 4, 0);
+ *ptr++ = ';';
+
+ *ptr++ = hexchars[O7 >> 4];
+ *ptr++ = hexchars[O7 & 0xf];
+ *ptr++ = ':';
+ ptr = mem2hex((char *)&registers[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':
+ remote_debug = !(remote_debug); /* 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 *)&registers[Y],
+ ptr + 32 * 4 * 2,
+ 8 * 4,
+ 0); /* Y, PSR, WIM, TBR, PC, NPC, FPSR, CPSR */
+ ptr = mem2hex((char *)&registers[CCSR],
+ ptr,
+ 8 * 4,
+ 0); /* CCSR, CCPR, CCCRCR, CCOR, CCOBR, CCIBR, CCIR */
+ ptr = mem2hex((char *)&registers[ASR1],
+ ptr,
+ 8 * 4,
+ 0); /* ASR1,ASR15,ASR17,ASR18,ASR19,ASR20,ASR21,ASR22 */
+#if 0 /* not implemented */
+ ptr = mem2hex((char *) &registers[AWR0],
+ ptr,
+ 32 * 4,
+ 0); /* Alternate Window Registers */
+#endif
+ }
+ break;
+
+ case 'G': /* set value of all the CPU registers - return OK */
+ case 'P': /* set value of one CPU register - return OK */
+ {
+ unsigned long *newsp, psr;
+
+ psr = registers[PSR];
+
+ ptr = &remcomInBuffer[1];
+
+ if (remcomInBuffer[0] == 'P') /* do a single register */
+ {
+ int regno;
+
+ if (hexToInt (&ptr, &regno)
+ && *ptr++ == '=')
+ if (regno >= L0 && regno <= I7)
+ hex2mem (ptr, sp + regno - L0, 4, 0);
+ else
+ hex2mem (ptr, (char *)&registers[regno], 4, 0);
+ else
+ {
+ strcpy (remcomOutBuffer, "P01");
+ break;
+ }
+ }
+ else
+ {
+ 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 *)&registers[Y],
+ 8 * 4, 0); /* Y,PSR,WIM,TBR,PC,NPC,FPSR,CPSR */
+ hex2mem(ptr + 72 * 4 * 2, (char *)&registers[CCSR],
+ 8 * 4, 0); /* CCSR,CCPR,CCCRCR,CCOR,CCOBR,CCIBR,CCIR */
+ hex2mem(ptr + 80 * 4 * 2, (char *)&registers[ASR1],
+ 8 * 4, 0); /* ASR1 ... ASR22 */
+#if 0 /* not implemented */
+ hex2mem(ptr + 88 * 4 * 2, (char *)&registers[AWR0],
+ 8 * 4, 0); /* Alternate Window Registers */
+#endif
+ }
+ /* 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
+ ");
+}
+
+#if 0 /* experimental and never finished, left here for reference */
+static void
+splet_temp(void)
+{
+ asm(" sub %sp,(16+1+6+1+121)*4,%sp ! Make room for input & locals
+ ! + hidden arg + arg spill
+ ! + doubleword alignment
+ ! + registers[121]
+
+! Leave a trail of breadcrumbs! (save register save area for debugging)
+ mov %sp, %l0
+ add %l0, 24*4, %l0
+ sethi %hi(_debug_registers), %l1
+ st %l0, [%lo(_debug_registers) + %l1]
+
+! Save the Alternate Register Set: (not implemented yet)
+! To save the Alternate Register set, we must:
+! 1) Save the current SP in some global location.
+! 2) Swap the register sets.
+! 3) Save the Alternate SP in the Y register
+! 4) Fetch the SP that we saved in step 1.
+! 5) Use that to save the rest of the regs (not forgetting ASP in Y)
+! 6) Restore the Alternate SP from Y
+! 7) Swap the registers back.
+
+! 1) Copy the current stack pointer to global _SAVED_STACK_POINTER:
+ sethi %hi(_saved_stack_pointer), %l0
+ st %sp, [%lo(_saved_stack_pointer) + %l0]
+
+! 2) Swap the register sets:
+ mov %psr, %l1
+ sethi %hi(0x10000), %l2
+ xor %l1, %l2, %l1
+ mov %l1, %psr
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+
+! 3) Save Alternate L0 in Y
+ wr %l0, 0, %y
+
+! 4) Load former SP into alternate SP, using L0
+ sethi %hi(_saved_stack_pointer), %l0
+ or %lo(_saved_stack_pointer), %l0, %l0
+ swap [%l0], %sp
+
+! 4.5) Restore alternate L0
+ rd %y, %l0
+
+! 5) Save the Alternate Window Registers
+ st %r0, [%sp + (24 + 88) * 4] ! AWR0
+ st %r1, [%sp + (24 + 89) * 4] ! AWR1
+ st %r2, [%sp + (24 + 90) * 4] ! AWR2
+ st %r3, [%sp + (24 + 91) * 4] ! AWR3
+ st %r4, [%sp + (24 + 92) * 4] ! AWR4
+ st %r5, [%sp + (24 + 93) * 4] ! AWR5
+ st %r6, [%sp + (24 + 94) * 4] ! AWR6
+ st %r7, [%sp + (24 + 95) * 4] ! AWR7
+ st %r8, [%sp + (24 + 96) * 4] ! AWR8
+ st %r9, [%sp + (24 + 97) * 4] ! AWR9
+ st %r10, [%sp + (24 + 98) * 4] ! AWR10
+ st %r11, [%sp + (24 + 99) * 4] ! AWR11
+ st %r12, [%sp + (24 + 100) * 4] ! AWR12
+ st %r13, [%sp + (24 + 101) * 4] ! AWR13
+! st %r14, [%sp + (24 + 102) * 4] ! AWR14 (SP)
+ st %r15, [%sp + (24 + 103) * 4] ! AWR15
+ st %r16, [%sp + (24 + 104) * 4] ! AWR16
+ st %r17, [%sp + (24 + 105) * 4] ! AWR17
+ st %r18, [%sp + (24 + 106) * 4] ! AWR18
+ st %r19, [%sp + (24 + 107) * 4] ! AWR19
+ st %r20, [%sp + (24 + 108) * 4] ! AWR20
+ st %r21, [%sp + (24 + 109) * 4] ! AWR21
+ st %r22, [%sp + (24 + 110) * 4] ! AWR22
+ st %r23, [%sp + (24 + 111) * 4] ! AWR23
+ st %r24, [%sp + (24 + 112) * 4] ! AWR24
+ st %r25, [%sp + (24 + 113) * 4] ! AWR25
+ st %r26, [%sp + (24 + 114) * 4] ! AWR26
+ st %r27, [%sp + (24 + 115) * 4] ! AWR27
+ st %r28, [%sp + (24 + 116) * 4] ! AWR28
+ st %r29, [%sp + (24 + 117) * 4] ! AWR29
+ st %r30, [%sp + (24 + 118) * 4] ! AWR30
+ st %r31, [%sp + (24 + 119) * 4] ! AWR21
+
+! Get the Alternate PSR (I hope...)
+
+ rd %psr, %l2
+ st %l2, [%sp + (24 + 120) * 4] ! APSR
+
+! Don't forget the alternate stack pointer
+
+ rd %y, %l3
+ st %l3, [%sp + (24 + 102) * 4] ! AWR14 (SP)
+
+! 6) Restore the Alternate SP (saved in Y)
+
+ rd %y, %o6
+
+
+! 7) Swap the registers back:
+
+ mov %psr, %l1
+ sethi %hi(0x10000), %l2
+ xor %l1, %l2, %l1
+ mov %l1, %psr
+ nop ! 3 nops after write to %psr (needed?)
+ nop
+ nop
+");
+}
+
+#endif
generated by cgit v1.1 at 2024-11-25 19:19:59 +0000