From bfc55a5d7cb60e153ea9294a1456192bed841276 Mon Sep 17 00:00:00 2001 From: Stu Grossman Date: Sun, 10 Jan 1993 03:46:55 +0000 Subject: [PATCH] * 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. --- gdb/ChangeLog | 23 +++++ gdb/sparc-stub.c | 212 +++++++++++++++++++++++++++-------------------- 2 files changed, 147 insertions(+), 88 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f8e19e861d..93dbb8bb46 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -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 diff --git a/gdb/sparc-stub.c b/gdb/sparc-stub.c index 47b98109d7..f58e0c2159 100644 --- a/gdb/sparc-stub.c +++ b/gdb/sparc-stub.c @@ -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(" - .text - .align 4 + .reserve trapstack, 1000 * 4, \"bss\", 8 + + .data + .align 4 -! Read the TBR. +in_trap_handler: + .word 0 - .globl _rdtbr -_rdtbr: - retl - mov %tbr, %o0 + .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 @@ -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 *)®isters[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 *)®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; @@ -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 + "); } -- 2.34.1