p->p_udata = &(*up)->u_d;
return 0;
}
-
-extern void *get_usp(void);
-extern void set_usp(void *p);
-
-/* We do as much exception processing in software as we can. This code
- is called from the asm trap hooks on the supervisor stack and expected
- to sort the mess out */
-
-/* The stackframe we work with looks like this when exception is called */
-
-struct trapdata {
- /* MOVEM.L with predecrement stores A7 to A0 then D7 to D0. In other
- words viewed in memory order it is D0-D7 then A0-A7 (A6 for us
- as we don't store A7) */
- uint32_t d[8];
- uint32_t a[7];
- uint16_t trap; /* Pushed second */
- uint16_t sr; /* Condition codes */
- /* The CPU pushed the frame which sits above the MOVEM */
- uint16_t exception[0]; /* CPU exception frame */
-};
-
-#define FRAME_A 1
-#define FRAME_B 2
-
-static void explode(struct trapdata *framedata, int type)
-{
- uint16_t *excp = framedata->exception;
- uint32_t *fv;
- unsigned int i = framedata->trap;
- unsigned int j;
-
- if (i > 12)
- i = 12;
-
- for (j = 0; j < i; j++)
- kputs(" '* ");
- kputchar('\n');
- for (j = 0; j < i; j++)
- kputs(" | ");
- kputchar('\n');
- for (j = 0; j < i; j++)
- kputs(".###. ");
- kputchar('\n');
- for (j = 0; j < i; j++)
- kputs("##### ");
- kputchar('\n');
- for (j = 0; j < i; j++)
- kputs("##### ");
- kputchar('\n');
- for (j = 0; j < i; j++)
- kputs("`###' ");
- kputchar('\n');
-
- kprintf("Trap: %d\n", framedata->trap);
- kprintf("Register Dump\nA: ");
- for (i = 0; i < 7; i++)
- kprintf("%p ", framedata->a[i]);
- kprintf("%p\nD: ", get_usp());
- for (i = 0; i < 8; i++)
- kprintf("%p ", framedata->d[i]);
- kprintf("\nSR: %x\n", framedata->sr);
-
- kprintf("Exception frame:\n");
- for (j = 0;j < 16; j++)
- kprintf("%d: %x\n", j, excp[j]);
-
- /* For now we only do 68000 */
- if (type == FRAME_A) {
- kputs((excp[0] & 0x10)?"R":"W");
- kprintf(" FC %x", excp[0] & 7);
- fv = (uint32_t *)(excp + 1);
- kprintf(" Addr %p IR %x ", *fv, excp[3]);
- excp += 4;
- }
- if (type == FRAME_A || type == FRAME_B) {
- fv = (uint32_t *)(excp + 1);
- kprintf("PC %p SR %x\n", *fv, *excp);
- }
-}
-
-/* Our caller did a movem of the registers to kstack then pushed an
- exception and other info. This all sits on the kstack but pass
- a pointer to it for flexibility.
-
- On return it will pull the state back and rte. We can thus adjust
- what happens according to need.
-
- To keep common code we push the same frame for all cases */
-
-static uint8_t pushw(uint16_t **usp, uint16_t v)
-{
- (*usp)--;
- return uputw(v, *usp);
-}
-
-static uint8_t pushl(uint16_t **usp, uint32_t v)
-{
- (*usp) -= 2;
- return uputl(v, *usp);
-}
-
-extern uint8_t kernel_flag;
-
-int exception(struct trapdata *framedata)
-{
- ptptr proc;
- unsigned int frame, fsize;
- uint8_t trap = framedata->trap;
- unsigned int sig = 0;
- uint16_t m;
- uint16_t *sp = (uint16_t *)framedata;
- uint16_t *usp = get_usp();
- uint16_t *unwind, *context;
- uint8_t err = 0;
- int i;
-
- /* We translate debug to SIGIOT and A and F line to SIGILL
- We will need to fix up 68000 v 68010 move to/from SR */
- static const uint8_t trap_to_sig[] = {
- 0, 0, SIGSEGV, SIGBUS, SIGILL, SIGFPE,
- SIGABRT/*CHK*/, SIGTRAP/*TRAPV */,
- SIGILL, SIGIOT, SIGILL, SIGFPE };
-
- proc = udata.u_ptab;
-
- /* Most synchronous exceptions are type B */
- /* FIXME: sizes need to become chip aware */
- frame = FRAME_B;
- fsize = 3; /* Three words on 68000 */
- /* TODO: On the 68010 there are at least 4 words as word 4 always holds
- the vector and format */
- if (trap == 0) {
- sig = udata.u_cursig;
- udata.u_cursig = 0;
- } else if (trap < 12) {
- if (trap < 4) {
- /* TODO: On a 68010 this frame is 29 words and the event is
- restartable (although not always usefully). We need to
- decide whether to set the restart flag case by case */
- frame = FRAME_A;
- fsize = 7;
- }
- sig = trap_to_sig[trap];
- } else if (trap >= 32 && trap < 48)
- sig = SIGTRAP;
- /* This processing only applies to synchronous hardware exceptions */
- if (trap) {
- /* Went boom in kernel space or without a user recovery */
- if (kernel_flag || sig == 0) {
- explode(framedata, frame);
- panic("trap");
- }
-
- /* Cheating here .. all our exceptions are low 16 signal */
- m = 1 << sig;
- /*
- * The caller is ignoring our signal. In some cases this is fine
- * but in others it's less clear (eg division by zero) and we
- * may need to take different action.
- */
- if (proc->p_sig[0].s_ignored & m)
- return 0;
- /* Weird case - we took a sync signal and the caller wants us to
- report it later. */
- if (proc->p_sig[0].s_held & m) {
- /* TODO: if it's not meaningfully restartable we should
- probably treat this as a kill */
- ssig(proc, sig);
- return 0;
- }
- recalc_cursig(); /* Put any async signal back */
- }
- if (udata.u_sigvec[sig] == SIG_DFL) {
- /* Default action for our signal ? */
- doexit(dump_core(sig));
- /* This will never return. We will go schedule new work */
- panic("exret");
- }
- /* build signal frame
-
- Our unwinder code does
- move.l 8(sp),sp
- movem.l a0-a1/d0-d1,(sp)+
- move.w (sp)+,ccr
- rts */
-
- /* Push the recovery PC */
-
- /* Now update the user stack */
- err |= pushw(&usp, sp[31 + fsize]);
- err |= pushw(&usp, sp[30 + fsize]);
-
- /* Patch the kernel exception frame */
- *(uint32_t *)(&sp[30 + fsize]) = (uint32_t)udata.u_sigvec[sig];
-
- /* FIXME: when we do ptrace we will need to support adding the T
- flag back here as the exception cleared it */
- err |= pushw(&usp, framedata->sr);
- /* Push A1 A0 D1 D0 to match MOVEM.L */
- err |= pushl(&usp, framedata->a[1]);
- err |= pushl(&usp, framedata->a[0]);
- err |= pushl(&usp, framedata->d[1]);
- err |= pushl(&usp, framedata->d[0]);
-
- /* Remember the target for undoing the frame */
- unwind = usp;
-
- /* Copy in the signal context itself. 30 words of registers, 2 of
- trap code and then the hardware exception */
- for (i = 0; i < 30 + 2 + fsize; i++)
- err |= pushw(&usp, *sp++);
- context = usp;
- err |= pushl(&usp, (uint32_t)unwind);
- /* Signal context is a secret extra non portable argument */
- err |= pushl(&usp, (uint32_t)context);
- /* We end it with the call frame as seen from the signal handler, a
- single argument and a return address */
- err |= pushl(&usp, sig);
- err |= pushl(&usp, udata.u_codebase + 0x04);
-
- set_usp(usp);
-
- if (err) {
- doexit(dump_core(SIGSTKFLT));
- panic("exret2");
- }
- /* Once built clear the restart state */
- udata.u_sigvec[sig] = SIG_DFL;
- /* Return, RTE and end up on the signal frame */
- return 1;
-}
public / FUZIX.git / commitdiff