source: trunk/hal/x86_64/hal_init.c @ 31

/*
 * hal_init.c - C initialization procedure for x86.
 *
 * Copyright (c) 2017 Maxime Villard
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-MKH.; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <hal_types.h>
#include <hal_boot.h>
#include <hal_segmentation.h>

#include <memcpy.h>
#include <thread.h>
#include <string.h>
#include <process.h>
#include <printk.h>
#include <vmm.h>
#include <core.h>
#include <cluster.h>

void x86_printf(char *s, ...);

static void gdt_create();
static void idt_create();
void cpu_attach();

/* -------------------------------------------------------------------------- */

void init_x86_64(paddr_t firstpa)
{
        x86_printf("[+] init_x86_64 called\n");

        extern uint64_t __kernel_end;
        x86_printf("__kernel_end: %p\n", (void *)&__kernel_end);

        /* Create the global structures */
        gdt_create();
        x86_printf("[+] gdt_create called\n");

        idt_create();
        x86_printf("[+] idt_create called\n");

        /* Attach cpu0 */
        cpu_attach();
        x86_printf("[+] cpu_attach called\n");

        char *buf = NULL;
        *buf = (char)0x01;

        int m = 0;
        int v = 1 / m;

        x86_printf("ALIVE!\n");

        while (1);
}

/* -------------------------------------------------------------------------- */

uint8_t gdtstore[PAGE_SIZE] __in_kdata;
uint8_t idtstore[PAGE_SIZE] __in_kdata;
struct tss cpu0_tss __in_kdata;
uint8_t cpu0_intr_stack[STKSIZE] __in_kdata;
uint8_t cpu0_dbfl_stack[STKSIZE] __in_kdata;
uint8_t cpu0_nmfl_stack[STKSIZE] __in_kdata;

static void
setregion(struct region_descriptor *rd, void *base, uint16_t limit)
{
        rd->rd_limit = limit;
        rd->rd_base = (uint64_t)base;
}

/* -------------------------------------------------------------------------- */

static void
gdt_set_memseg(struct gdt_memseg *sd, void *base, size_t limit,
        int type, int dpl, int gran, int is64)
{
        sd->sd_lolimit = (unsigned)limit;
        sd->sd_lobase = (unsigned long)base;
        sd->sd_type = type;
        sd->sd_dpl = dpl;
        sd->sd_p = 1;
        sd->sd_hilimit = (unsigned)limit >> 16;
        sd->sd_avl = 0;
        sd->sd_long = is64;
        sd->sd_def32 = 0;
        sd->sd_gran = gran;
        sd->sd_hibase = (unsigned long)base >> 24;
}

static void
gdt_set_sysseg(struct gdt_sysseg *sd, void *base, size_t limit,
        int type, int dpl, int gran)
{
        memset(sd, 0, sizeof *sd);
        sd->sd_lolimit = (unsigned)limit;
        sd->sd_lobase = (uint64_t)base;
        sd->sd_type = type;
        sd->sd_dpl = dpl;
        sd->sd_p = 1;
        sd->sd_hilimit = (unsigned)limit >> 16;
        sd->sd_gran = gran;
        sd->sd_hibase = (uint64_t)base >> 24;
}

static void gdt_create()
{
        memset(&gdtstore, 0, PAGE_SIZE);

        /* Flat segments */
        gdt_set_memseg(GDT_ADDR_MEM(gdtstore, GDT_KCODE_SEL), 0,
            0xfffff, SDT_MEMERA, SEL_KPL, 1, 1);
        gdt_set_memseg(GDT_ADDR_MEM(gdtstore, GDT_KDATA_SEL), 0,
            0xfffff, SDT_MEMRWA, SEL_KPL, 1, 1);
        gdt_set_memseg(GDT_ADDR_MEM(gdtstore, GDT_UCODE_SEL), 0,
            0xfffff, SDT_MEMERA, SEL_UPL, 1, 1);
        gdt_set_memseg(GDT_ADDR_MEM(gdtstore, GDT_UDATA_SEL), 0,
            0xfffff, SDT_MEMRWA, SEL_UPL, 1, 1);
}

void cpu_load_gdt()
{
        struct region_descriptor region;
        setregion(&region, &gdtstore, PAGE_SIZE - 1);
        lgdt(&region);
}

/* -------------------------------------------------------------------------- */

static void
idt_set_seg(struct idt_seg *seg, void *func, int ist, int type, int dpl, int sel)
{
        seg->gd_looffset = (uint64_t)func & 0xffff;
        seg->gd_selector = sel;
        seg->gd_ist = ist;
        seg->gd_type = type;
        seg->gd_dpl = dpl;
        seg->gd_p = 1;
        seg->gd_hioffset = (uint64_t)func >> 16;
        seg->gd_zero = 0;
        seg->gd_xx1 = 0;
        seg->gd_xx2 = 0;
        seg->gd_xx3 = 0;
}

static void idt_create()
{
        extern uint64_t x86_traps[];
        struct idt_seg *idt;
        size_t i;

        idt = (struct idt_seg *)&idtstore;
        for (i = 0; i < NCPUIDT; i++) {
                idt_set_seg(&idt[i], (void *)x86_traps[i], 0, SDT_SYS386IGT,
                    SEL_KPL, GDT_FIXED_SEL(GDT_KCODE_SEL, SEL_KPL));
        }
}

void cpu_load_idt()
{
        struct region_descriptor region;
        setregion(&region, &idtstore, PAGE_SIZE - 1);
        lidt(&region);
}

/* -------------------------------------------------------------------------- */

/*
 * The gdt bitmap must be per-cluster.
 */
int tss_alloc(struct tss *tss)
{
        int slot;

        /* Once we have proper SMP support, we will change that */
        slot = GDT_CPU0TSS_SEL;

        gdt_set_sysseg(GDT_ADDR_SYS(gdtstore, slot), tss,
            sizeof(*tss) - 1, SDT_SYS386TSS, SEL_KPL, 0);

        return GDT_DYNAM_SEL(slot, SEL_KPL);
}

void cpu_create_tss()
{
        struct tss *tss = &cpu0_tss;
        int sel;

        /* Create the tss */
        memset(tss, 0, sizeof(*tss));
        tss->tss_iobase = IOMAP_INVALOFF << 16;
        tss->tss_ist[0] = (uint64_t)cpu0_intr_stack + STKSIZE;
        tss->tss_ist[1] = (uint64_t)cpu0_dbfl_stack + STKSIZE;
        tss->tss_ist[2] = (uint64_t)cpu0_nmfl_stack + STKSIZE;
        sel = tss_alloc(tss);

        /* Load it */
        ltr(sel);
}

/* -------------------------------------------------------------------------- */

void cpu_attach()
{
        cpu_load_gdt();
        cpu_load_idt();
        cpu_create_tss();
}