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Implement interrupts

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This commit is contained in:
Kamil Kowalczyk
2025-08-19 22:51:33 +02:00
parent 92ccd189e7
commit 3f6df79885
14 changed files with 455 additions and 101 deletions
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99
kernel/hal/x86_64/gdt.c
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@ -2,8 +2,18 @@
#include <stddef.h>
#include "compiler/attr.h"
#include "hal/hal.h"
#include "gdt.h"
#define GDT_SIZE 5
#define GDT_PRESENT 0x80
#define GDT_TSS 0x89
#define KSTACK 8192
ALIGNED(16) static uint8_t kernelstack[KSTACK];
#define ISTS 7
#define ISTACK 4096
ALIGNED(16) static uint8_t iststacks[ISTS][ISTACK];
typedef struct {
uint16_t limitlow;
@ -31,64 +41,73 @@ typedef struct {
uint64_t rsp1;
uint64_t rsp2;
uint64_t resv1;
uint64_t ist[7];
uint64_t ist[ISTS];
uint64_t resv2;
uint16_t resv3;
uint16_t iopb_off;
} PACKED Tss;
static Tss tss = {0};
static ExtendedGdt *curgdt = NULL;
ALIGNED(16) static Tss tss = {0};
ALIGNED(16) static ExtendedGdt gdt = {0};
#define KCODE 0x08
#define KDATA 0x10
#define UCODE 0x18
#define UDATA 0x20
#define TSS 0x28
#define GDT_PRESENT 0x80
#define GDT_TSS 0x89
static uint64_t gdt_curretbase(void) {
GdtPtr gdtr;
asm volatile("sgdt %0" : "=m"(gdtr));
return gdtr.base;
}
void gdt_setentry(GdtEntry *entry, uint32_t base, uint32_t limit, uint8_t access, uint8_t gran) {
entry->baselow = base & 0xffff;
entry->basemid = (base >> 16) & 0xff;
entry->basehigh = (base >> 24) & 0xff;
entry->limitlow = limit & 0xffff;
entry->gran = ((limit >> 16) & 0x0f) | (gran & 0xf0);
entry->access = access;
void gdt_setentry(GdtEntry *ent, uint32_t base, uint32_t limit, uint32_t acc, uint8_t gran) {
ent->baselow = base & 0xffff;
ent->basemid = (base >> 16) & 0xff;
ent->basehigh = (base >> 24) & 0xff;
ent->limitlow = limit & 0xffff;
ent->gran = ((limit >> 16) & 0x0f) | (gran & 0xf0);
ent->access = acc;
}
void gdt_init(void) {
uint64_t base = gdt_curretbase();
curgdt = (ExtendedGdt *)base;
hal_memset(&tss, 0, sizeof(tss));
tss.iopb_off = sizeof(tss);
tss.rsp0 = (uint64_t)(kernelstack + sizeof(kernelstack));
for (size_t i = 0; i < ISTS; i++) {
tss.ist[i] = (uint64_t)(iststacks[i] + sizeof(iststacks[i]));
}
uint64_t tss_base = (uint64_t)&tss;
uint32_t tss_limit = sizeof(tss) - 1;
gdt_setentry(&curgdt->tsslow, tss_base & 0xFFFFFFFF, tss_limit, GDT_PRESENT | GDT_TSS, 0x0);
GdtEntry *tsshigh = &curgdt->tsshigh;
tsshigh->baselow = (tss_base >> 32) & 0xffff;
tsshigh->basemid = (tss_base >> 48) & 0xff;
tsshigh->basehigh = (tss_base >> 56) & 0xff;
tsshigh->access = 0;
tsshigh->gran = 0;
tsshigh->limitlow = 0;
gdt_setentry(&gdt.old[0], 0, 0, 0, 0);
gdt_setentry(&gdt.old[1], 0, 0xFFFFF, 0x9a, 0xA0);
gdt_setentry(&gdt.old[2], 0, 0xFFFFF, 0x92, 0xA0);
gdt_setentry(&gdt.old[3], 0, 0xFFFFF, 0xfa, 0xA0);
gdt_setentry(&gdt.old[4], 0, 0xFFFFF, 0xf2, 0xA0);
gdt_setentry(&gdt.tsslow, tss_base & 0xFFFFFFFF, tss_limit, GDT_PRESENT | GDT_TSS, 0x0);
uint32_t tssbasehi = tss_base >> 32;
gdt.tsshigh.limitlow = tssbasehi & 0xffff;
gdt.tsshigh.baselow = (tssbasehi >> 16) & 0xffff;
gdt.tsshigh.basemid = 0;
gdt.tsshigh.basehigh = 0;
gdt.tsshigh.access = 0;
gdt.tsshigh.gran = 0;
GdtPtr gdtr;
asm volatile("sgdt %0" : "=m"(gdtr));
gdtr.limit = sizeof(ExtendedGdt) - 1;
gdtr.limit = sizeof(gdt) - 1;
gdtr.base = (uint64_t)&gdt;
asm volatile("lgdt %0" :: "m"(gdtr));
asm volatile("ltr %0" :: "r"((uint16_t)0x28));
asm volatile(
"pushq %[kcode]\n"
"lea 1f(%%rip), %%rax\n"
"pushq %%rax\n"
"lretq\n"
"1:\n"
"movw %[kdata], %%ax\n"
"movw %%ax, %%ds\n"
"movw %%ax, %%es\n"
"movw %%ax, %%ss\n"
:
: [kcode] "i"(KCODE), [kdata] "i"(KDATA)
: "rax", "memory"
);
asm volatile("ltr %0" :: "r"((uint16_t)TSS));
}