*
* Modified for SPARC by Stu Grossman, 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.
*
* ? 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
*
#include <string.h>
#include <signal.h>
-#include <memory.h>
/************************************************************************
*
* external low-level support routines
*/
-extern putDebugChar(); /* write a single character */
-extern getDebugChar(); /* read and return a single char */
+extern void putDebugChar(); /* write a single character */
+extern int 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; /* boolean flag. != 0 means we've been initialized */
+static int initialized = 0; /* !0 means we've been initialized */
static void set_mem_fault_trap();
/*************************** ASSEMBLY CODE MACROS *************************/
/* */
-#define BREAKPOINT() asm(" ta 1");
-
-extern unsigned long rdtbr();
+extern void trap_low();
asm("
- .text
- .align 4
+ .reserve trapstack, 1000 * 4, \"bss\", 8
-! Read the TBR.
+ .data
+ .align 4
- .globl _rdtbr
-_rdtbr:
- retl
- mov %tbr, %o0
+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.
-trap_low:
+ .globl _trap_low
+_trap_low:
mov %psr, %l0
mov %wim, %l3
mov %g1, %l4 ! Save g1, we use it to hold the wim
srl %l3, 1, %g1 ! Rotate wim right
- sll %l3, 8-1, %l5
- or %l5, %g1, %g1
+ 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.
+
+ 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
mov %l4, %g1 ! Restore %g1
window_fine:
- sub %fp, (16+1+6+1+72)*4, %sp ! Make room for input & locals
+ 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+72)*4,%sp ! Make room for input & locals
! + hidden arg + arg spill
! + doubleword alignment
! + registers[72] local var
- std %g0, [%fp + (-72 + 0) * 4] ! registers[Gx]
- std %g2, [%fp + (-72 + 2) * 4]
- std %g4, [%fp + (-72 + 4) * 4]
- std %g6, [%fp + (-72 + 6) * 4]
+ 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, [%fp + (-72 + 8) * 4] ! registers[Ox]
- std %i2, [%fp + (-72 + 10) * 4]
- std %i4, [%fp + (-72 + 12) * 4]
- std %i6, [%fp + (-72 + 14) * 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, [%fp + (-72 + 64) * 4] ! Y
- st %l0, [%fp + (-72 + 65) * 4] ! PSR
- st %l3, [%fp + (-72 + 66) * 4] ! WIM
- st %l5, [%fp + (-72 + 67) * 4] ! TBR
- st %l1, [%fp + (-72 + 68) * 4] ! PC
- st %l2, [%fp + (-72 + 69) * 4] ! NPC
+ 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
mov %l4, %psr ! Turn on traps, disable interrupts
call _handle_exception
- add %fp, -72 * 4, %o0 ! Pass address of registers
-
- restore ! Ensure that previous window is valid
- save %g0, %g0, %g0 ! by causing a window_underflow trap
+ add %sp, 24 * 4, %o0 ! Pass address of registers
! Reload all of the registers that aren't on the stack
- ld [%fp + (-72 + 1) * 4], %g1 ! registers[Gx]
- ldd [%fp + (-72 + 2) * 4], %g2
- ldd [%fp + (-72 + 4) * 4], %g4
- ldd [%fp + (-72 + 6) * 4], %g6
+ 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 [%fp + (-72 + 8) * 4], %o0 ! registers[Ox]
- ldd [%fp + (-72 + 10) * 4], %o2
- ldd [%fp + (-72 + 12) * 4], %o4
- ldd [%fp + (-72 + 14) * 4], %o6
+ 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
+
+ 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
- ldd [%fp + (-72 + 64) * 4], %l0 ! Y & PSR
- ldd [%fp + (-72 + 68) * 4], %l2 ! PC & NPC
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;
+hex (unsigned char ch)
{
if (ch >= 'a' && ch <= 'f')
return ch-'a'+10;
return -1;
}
+static char remcomInBuffer[BUFMAX];
+static char remcomOutBuffer[BUFMAX];
+
/* scan for the sequence $<data>#<checksum> */
-static void
-getpacket(buffer)
- char *buffer;
+unsigned char *
+getpacket (void)
{
+ unsigned char *buffer = &remcomInBuffer[0];
unsigned char checksum;
unsigned char xmitcsum;
- int i;
int count;
- unsigned char ch;
+ char ch;
- do
+ while (1)
{
/* wait around for the start character, ignore all other characters */
- while ((ch = getDebugChar()) != '$') ;
+ while ((ch = getDebugChar ()) != '$')
+ ;
+retry:
checksum = 0;
xmitcsum = -1;
-
count = 0;
/* now, read until a # or end of buffer is found */
- while (count < BUFMAX)
+ while (count < BUFMAX - 1)
{
- ch = getDebugChar();
+ ch = getDebugChar ();
+ if (ch == '$')
+ goto retry;
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 1
- /* Humans shouldn't have to figure out checksums to type to it. */
- putDebugChar ('+');
- return;
-#endif
+ ch = getDebugChar ();
+ xmitcsum = hex (ch) << 4;
+ ch = getDebugChar ();
+ xmitcsum += hex (ch);
+
if (checksum != xmitcsum)
- putDebugChar('-'); /* failed checksum */
+ {
+ putDebugChar ('-'); /* failed checksum */
+ }
else
{
- putDebugChar('+'); /* successful transfer */
+ 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];
+ putDebugChar (buffer[0]);
+ putDebugChar (buffer[1]);
+
+ return &buffer[3];
}
+
+ return &buffer[0];
}
}
}
- while (checksum != xmitcsum);
}
/* send the packet in buffer. */
static void
-putpacket(buffer)
- unsigned char *buffer;
+putpacket (unsigned char *buffer)
{
unsigned char checksum;
int count;
while (ch = buffer[count])
{
- if (! putDebugChar(ch))
- return;
+ putDebugChar(ch);
checksum += ch;
count += 1;
}
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;
*/
static unsigned char *
-mem2hex(mem, buf, count, may_fault)
- unsigned char *mem;
- unsigned char *buf;
- int count;
- int may_fault;
+mem2hex (unsigned char *mem, unsigned char *buf, int count, int may_fault)
{
unsigned char ch;
* 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;
+hex2mem (unsigned char *buf, unsigned char *mem, int count, int may_fault)
{
int i;
unsigned char ch;
{0, 0} /* Must be last */
};
-/* Each entry in the trap vector occupies four words. */
+/* Set up exception handlers for tracing and breakpoints */
-struct trap_entry
+void
+set_debug_traps (void)
{
- unsigned long ti[4];
-};
+ struct hard_trap_info *ht;
-extern struct trap_entry fltr_proto;
-extern struct trap_entry fltr_set_mem_err;
-asm ("
- .data
- .globl _fltr_proto
- .align 4
-_fltr_proto: ! First level trap routine prototype
- sethi %hi(trap_low), %l0
- jmpl %lo(trap_low)+%l0, %g0
- nop
- nop
+ for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+ exceptionHandler(ht->tt, trap_low);
+
+ 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
-
- .text
");
-/* Set up exception handlers for tracing and breakpoints */
-
-void
-set_debug_traps()
-{
- struct trap_entry *tb; /* Trap vector base address */
- struct hard_trap_info *ht;
-
- tb = (struct trap_entry *)(rdtbr() & ~0xfff);
-
- for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
- tb[ht->tt] = fltr_proto;
-
- /* In case GDB is started before us, ack any packets (presumably
- "$?#xx") sitting there. */
-
- putDebugChar ('+');
-
- initialized = 1;
-}
-
static void
-set_mem_fault_trap(enable)
- int enable;
+set_mem_fault_trap (int enable)
{
- struct trap_entry *tb; /* Trap vector base address */
-
+ extern void fltr_set_mem_err();
mem_err = 0;
- tb = (struct trap_entry *)(rdtbr() & ~0xfff);
-
if (enable)
- tb[9] = fltr_set_mem_err;
+ exceptionHandler(9, fltr_set_mem_err);
else
- tb[9] = fltr_proto;
+ exceptionHandler(9, trap_low);
}
/* Convert the SPARC hardware trap type code to a unix signal number. */
static int
-computeSignal(tt)
- int tt;
+computeSignal (int tt)
{
struct hard_trap_info *ht;
*intValue = (*intValue << 4) | hexValue;
numChars ++;
- *ptr++;
+ (*ptr)++;
}
return (numChars);
* otherwise.
*/
+extern void breakinst();
+
static void
-handle_exception (registers)
- unsigned long *registers;
+handle_exception (unsigned long *registers)
{
int tt; /* Trap type */
int sigval;
restore
");
+ if (registers[PC] == (unsigned long)breakinst)
+ {
+ registers[PC] = registers[NPC];
+ registers[NPC] += 4;
+ }
+
sp = (unsigned long *)registers[SP];
tt = (registers[TBR] >> 4) & 0xff;
{
remcomOutBuffer[0] = 0;
- getpacket(remcomInBuffer);
- switch (remcomInBuffer[0])
+ ptr = getpacket();
+ switch (*ptr++)
{
case '?':
remcomOutBuffer[0] = 'S';
remcomOutBuffer[3] = 0;
break;
- case 'd':
- /* toggle debug flag */
+ 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, 8 * 4, 0); /* L regs */
- ptr = mem2hex(sp + 8, ptr, 8 * 4, 0); /* I regs */
+ ptr = mem2hex(sp + 0, ptr, 16 * 4, 0); /* L & I regs */
memset(ptr, '0', 32 * 8); /* Floating point */
mem2hex((char *)®isters[Y],
ptr + 32 * 4 * 2,
case 'G': /* set the value of the CPU registers - return OK */
{
- ptr = &remcomInBuffer[1];
+ unsigned long *newsp, psr;
+
+ psr = registers[PSR];
+
hex2mem(ptr, (char *)registers, 16 * 4, 0); /* G & O regs */
- hex2mem(ptr + 16 * 4 * 2, sp + 0, 8 * 4, 0); /* L regs */
- hex2mem(ptr + 24 * 4 * 2, sp + 8, 8 * 4, 0); /* I 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 */
+
+ /* 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))
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)
break;
case 'c': /* cAA..AA Continue at address AA..AA(optional) */
- case 's': /* sAA..AA Step one instruction from 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
-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;
+ case 't': /* Test feature */
+ asm (" std %f30,[%sp]");
+ break;
#endif
+ case 'r': /* Reset */
+ asm ("call 0
+ nop ");
+ break;
} /* switch */
/* reply to the request */
the debugger. */
void
-breakpoint()
+breakpoint (void)
{
- if (initialized)
- BREAKPOINT();
+ if (!initialized)
+ return;
+
+ asm(" .globl _breakinst
+
+ _breakinst: ta 1
+ ");
}
projects / binutils.git / blobdiff