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pc, pc64: load idt early in trapinit0() 

loading the interrupt vector table early allows
us to handle traps during bootup before mmuinit()
which gives better diagnostics for debugging.

we also can handle general protection fault on
rdmsr() and wrmsr() which helps during
cpuidentify() and archinit() when probing for
cpu features.
front
cinap_lenrek 2020-11-17 23:30:09 +01:00
parent 8cb33f2f18
commit 972f95aa63
4 changed files with 20 additions and 27 deletions
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4
sys/src/9/pc/main.c
View File

@ -23,15 +23,13 @@ void
main(void)
{
mach0init();
trapinit0();
bootargsinit();
ioinit();
i8250console();
quotefmtinstall();
screeninit();
print("\nPlan 9\n");
trapinit0();
i8253init();
cpuidentify();
meminit0();

20
sys/src/9/pc/trap.c
View File

@ -9,8 +9,6 @@
#include "../port/error.h"
#include <trace.h>
static int trapinited;
void noted(Ureg*, ulong);
static void debugexc(Ureg*, void*);
@ -197,13 +195,13 @@ trapinit0(void)
int d1, v;
ulong vaddr;
Segdesc *idt;
ushort ptr[3];
idt = (Segdesc*)IDTADDR;
vaddr = (ulong)vectortable;
for(v = 0; v < 256; v++){
d1 = (vaddr & 0xFFFF0000)|SEGP;
switch(v){
case VectorBPT:
d1 |= SEGPL(3)|SEGIG;
break;
@ -220,6 +218,10 @@ trapinit0(void)
idt[v].d1 = d1;
vaddr += 6;
}
ptr[0] = sizeof(Segdesc)*256-1;
ptr[1] = IDTADDR & 0xFFFF;
ptr[2] = IDTADDR >> 16;
lidt(ptr);
}
void
@ -237,7 +239,6 @@ trapinit(void)
nmienable();
addarchfile("irqalloc", 0444, irqallocread, nil);
trapinited = 1;
}
static char* excname[32] = {
@ -328,13 +329,6 @@ trap(Ureg* ureg)
Vctl *ctl, *v;
Mach *mach;
if(!trapinited){
/* fault386 can give a better error message */
if(ureg->trap == VectorPF)
fault386(ureg, nil);
panic("trap %lud: not ready", ureg->trap);
}
m->perf.intrts = perfticks();
user = userureg(ureg);
if(user){
@ -482,6 +476,10 @@ trap(Ureg* ureg)
return;
}
}
/* early fault before trapinit() */
if(vno == VectorPF)
fault386(ureg, 0);
}
dumpregs(ureg);

2
sys/src/9/pc64/main.c
View File

@ -175,13 +175,13 @@ void
main(void)
{
mach0init();
trapinit0();
bootargsinit();
ioinit();
i8250console();
quotefmtinstall();
screeninit();
print("\nPlan 9\n");
trapinit0();
i8253init();
cpuidentify();
meminit0();

21
sys/src/9/pc64/trap.c
View File

@ -9,8 +9,6 @@
#include "../port/error.h"
#include <trace.h>
static int trapinited;
void noted(Ureg*, ulong);
static void debugexc(Ureg*, void*);
@ -194,13 +192,13 @@ trapinit0(void)
u32int d1, v;
uintptr vaddr;
Segdesc *idt;
uintptr ptr[2];
idt = (Segdesc*)IDTADDR;
vaddr = (uintptr)vectortable;
for(v = 0; v < 256; v++){
d1 = (vaddr & 0xFFFF0000)|SEGP;
switch(v){
case VectorBPT:
d1 |= SEGPL(3)|SEGIG;
break;
@ -224,6 +222,9 @@ trapinit0(void)
vaddr += 6;
}
((ushort*)&ptr[1])[-1] = sizeof(Segdesc)*512-1;
ptr[1] = IDTADDR;
lidt(&((ushort*)&ptr[1])[-1]);
}
void
@ -240,7 +241,6 @@ trapinit(void)
trapenable(Vector15, unexpected, 0, "unexpected");
nmienable();
addarchfile("irqalloc", 0444, irqallocread, nil);
trapinited = 1;
}
static char* excname[32] = {
@ -324,13 +324,6 @@ trap(Ureg *ureg)
Vctl *ctl, *v;
Mach *mach;
if(!trapinited){
/* faultamd64 can give a better error message */
if(ureg->type == VectorPF)
faultamd64(ureg, nil);
panic("trap %llud: not ready", ureg->type);
}
m->perf.intrts = perfticks();
user = userureg(ureg);
if(user){
@ -447,11 +440,15 @@ trap(Ureg *ureg)
return;
}
} else if(pc == _peekinst){
if(vno == VectorGPF){
if(vno == VectorGPF || vno == VectorPF){
ureg->pc += 2;
return;
}
}
/* early fault before trapinit() */
if(vno == VectorPF)
faultamd64(ureg, 0);
}
dumpregs(ureg);