* sparc-stub.c: Use a seperate stack for our traps.

* Handle recursive traps.
	* Remove all trap init code.  This needs to be done by the
	environment.
	* (set_mem_fault_trap):  Call exceptionHandler() to setup this
	trap.
	* (handle_exception):  See if we are at breakinst, if so, then
	advance PC sp that users can just step out of breakpoint().
	* (case 'G'):  Don't let GDB hack CWP.  Also, copy saved regs to
	new place if SP has changed.
	* (case 's'):  Get rid of this, we can't do it yet.
	* (case 't'):  New command to test any old random feature.
	* (case 'r'):  New command to reset the system.
	* (breakpoint):  Add label to breakpoint trap instruction so that
	handle_exception() can detect where we are and get past the
	breakpoint trivially.
This commit is contained in:
Stu Grossman 1993-01-10 03:46:55 +00:00
parent 7cc2923a8f
commit bfc55a5d7c
2 changed files with 147 additions and 88 deletions

View file

@ -1,7 +1,30 @@
Sat Jan 9 19:31:43 1993 Stu Grossman (grossman at cygnus.com)
* sparc-stub.c: Use a seperate stack for our traps.
* Handle recursive traps.
* Remove all trap init code. This needs to be done by the
environment.
* (set_mem_fault_trap): Call exceptionHandler() to setup this
trap.
* (handle_exception): See if we are at breakinst, if so, then
advance PC sp that users can just step out of breakpoint().
* (case 'G'): Don't let GDB hack CWP. Also, copy saved regs to
new place if SP has changed.
* (case 's'): Get rid of this, we can't do it yet.
* (case 't'): New command to test any old random feature.
* (case 'r'): New command to reset the system.
* (breakpoint): Add label to breakpoint trap instruction so that
handle_exception() can detect where we are and get past the
breakpoint trivially.
Thu Jan 7 13:33:06 1993 Ian Lance Taylor (ian@cygnus.com)
* mips-pinsn.c: Actual work now done by opcodes/mips-dis.c.
Thu Jan 7 09:21:51 1993 david d `zoo' zuhn (zoo at cirdan.cygnus.com)
* configure.in: recognise all sparclite variants
Wed Jan 6 10:14:51 1993 Steve Chamberlain (sac@thepub.cygnus.com)
* symfile.c: If O_BINARY isn't defined, set it to 0, call openp for

View file

@ -99,7 +99,7 @@ extern getDebugChar(); /* read and return a single char */
/* 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();
@ -123,27 +123,27 @@ enum regnames {G0, G1, G2, G3, G4, G5, G6, G7,
/*************************** ASSEMBLY CODE MACROS *************************/
/* */
#define BREAKPOINT() asm(" ta 1");
extern unsigned long rdtbr();
extern void trap_low();
asm("
.reserve trapstack, 1000 * 4, \"bss\", 8
.data
.align 4
in_trap_handler:
.word 0
.text
.align 4
! Read the TBR.
.globl _rdtbr
_rdtbr:
retl
mov %tbr, %o0
! 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
@ -176,29 +176,39 @@ trap_low:
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
@ -206,28 +216,34 @@ window_fine:
mov %l4, %psr ! Turn on traps, disable interrupts
call _handle_exception
add %fp, -72 * 4, %o0 ! Pass address of registers
add %sp, 24 * 4, %o0 ! Pass address of registers
restore ! Ensure that previous window is valid
save %g0, %g0, %g0 ! by causing a window_underflow trap
! 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 [%fp + (-72 + 64) * 4], %l0 ! Y & PSR
ldd [%fp + (-72 + 68) * 4], %l2 ! PC & NPC
ldd [%sp + (24 + 64) * 4], %l0 ! Y & PSR
ldd [%sp + (24 + 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
");
@ -289,6 +305,11 @@ getpacket(buffer)
{
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
@ -434,51 +455,15 @@ static struct hard_trap_info
{0, 0} /* Must be last */
};
/* Each entry in the trap vector occupies four words. */
struct trap_entry
{
unsigned long ti[4];
};
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
! 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.
_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;
exceptionHandler(ht->tt, trap_low);
/* In case GDB is started before us, ack any packets (presumably
"$?#xx") sitting there. */
@ -488,20 +473,33 @@ set_debug_traps()
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;
{
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. */
@ -553,6 +551,8 @@ hexToInt(char **ptr, int *intValue)
* otherwise.
*/
extern void breakinst();
static void
handle_exception (registers)
unsigned long *registers;
@ -584,6 +584,12 @@ handle_exception (registers)
restore
");
if (registers[PC] == (unsigned long)breakinst)
{
registers[PC] = registers[NPC];
registers[NPC] += 4;
}
sp = (unsigned long *)registers[SP];
tt = (registers[TBR] >> 4) & 0xff;
@ -652,8 +658,7 @@ handle_exception (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 *)&registers[Y],
ptr + 32 * 4 * 2,
@ -664,12 +669,29 @@ handle_exception (registers)
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, 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 *)&registers[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;
@ -712,7 +734,6 @@ handle_exception (registers)
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];
@ -733,6 +754,16 @@ handle_exception (registers)
/* kill the program */
case 'k' : /* do nothing */
break;
#if 0
case 't': /* Test feature */
asm (" std %f31,[%sp]");
break;
#endif
case 'r': /* Reset */
asm ("call 0
nop ");
break;
#if 0
Disabled until we can unscrew this properly
@ -785,6 +816,11 @@ x1: break;
void
breakpoint()
{
if (initialized)
BREAKPOINT();
if (!initialized)
return;
asm(" .globl _breakinst
_breakinst: ta 1
");
}