Archipelago » qemu

/*

 *  i386 helpers (without register variable usage)

 * 

 *  Copyright (c) 2003 Fabrice Bellard

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <stdarg.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <inttypes.h>

#include <signal.h>

#include <assert.h>

#include <sys/mman.h>

#include "cpu.h"

#include "exec-all.h"

//#define DEBUG_MMU

CPUX86State *cpu_x86_init(void)

{

    CPUX86State *env;

    int i;

    static int inited;

    cpu_exec_init();

    env = malloc(sizeof(CPUX86State));

    if (!env)

        return NULL;

    memset(env, 0, sizeof(CPUX86State));

    /* basic FPU init */

    for(i = 0;i < 8; i++)

        env->fptags[i] = 1;

    env->fpuc = 0x37f;

    /* flags setup : we activate the IRQs by default as in user mode */

    env->eflags = 0x2 | IF_MASK;

    tlb_flush(env);

#ifdef CONFIG_SOFTMMU

    env->hflags |= HF_SOFTMMU_MASK;

#endif

    /* init various static tables */

    if (!inited) {

        inited = 1;

        optimize_flags_init();

    }

    return env;

}

void cpu_x86_close(CPUX86State *env)

{

    free(env);

}

/***********************************************************/

/* x86 debug */

static const char *cc_op_str[] = {

    "DYNAMIC",

    "EFLAGS",

    "MULB",

    "MULW",

    "MULL",

    "ADDB",

    "ADDW",

    "ADDL",

    "ADCB",

    "ADCW",

    "ADCL",

    "SUBB",

    "SUBW",

    "SUBL",

    "SBBB",

    "SBBW",

    "SBBL",

    "LOGICB",

    "LOGICW",

    "LOGICL",

    "INCB",

    "INCW",

    "INCL",

    "DECB",

    "DECW",

    "DECL",

    "SHLB",

    "SHLW",

    "SHLL",

    "SARB",

    "SARW",

    "SARL",

};

void cpu_x86_dump_state(CPUX86State *env, FILE *f, int flags)

{

    int eflags, i;

    char cc_op_name[32];

    static const char *seg_name[6] = { "ES", "CS", "SS", "DS", "FS", "GS" };

    eflags = env->eflags;

    fprintf(f, "EAX=%08x EBX=%08x ECX=%08x EDX=%08x\n"

            "ESI=%08x EDI=%08x EBP=%08x ESP=%08x\n"

            "EIP=%08x EFL=%08x [%c%c%c%c%c%c%c]    CPL=%d II=%d\n",

            env->regs[R_EAX], env->regs[R_EBX], env->regs[R_ECX], env->regs[R_EDX], 

            env->regs[R_ESI], env->regs[R_EDI], env->regs[R_EBP], env->regs[R_ESP], 

            env->eip, eflags,

            eflags & DF_MASK ? 'D' : '-',

            eflags & CC_O ? 'O' : '-',

            eflags & CC_S ? 'S' : '-',

            eflags & CC_Z ? 'Z' : '-',

            eflags & CC_A ? 'A' : '-',

            eflags & CC_P ? 'P' : '-',

            eflags & CC_C ? 'C' : '-',

            env->hflags & HF_CPL_MASK, 

            (env->hflags >> HF_INHIBIT_IRQ_SHIFT) & 1);

    for(i = 0; i < 6; i++) {

        SegmentCache *sc = &env->segs[i];

        fprintf(f, "%s =%04x %08x %08x %08x\n",

                seg_name[i],

                sc->selector,

                (int)sc->base,

                sc->limit,

                sc->flags);

    }

    fprintf(f, "LDT=%04x %08x %08x %08x\n",

            env->ldt.selector,

            (int)env->ldt.base,

            env->ldt.limit,

            env->ldt.flags);

    fprintf(f, "TR =%04x %08x %08x %08x\n",

            env->tr.selector,

            (int)env->tr.base,

            env->tr.limit,

            env->tr.flags);

    fprintf(f, "GDT=     %08x %08x\n",

            (int)env->gdt.base, env->gdt.limit);

    fprintf(f, "IDT=     %08x %08x\n",

            (int)env->idt.base, env->idt.limit);

    fprintf(f, "CR0=%08x CR2=%08x CR3=%08x CR4=%08x\n",

            env->cr[0], env->cr[2], env->cr[3], env->cr[4]);

    if (flags & X86_DUMP_CCOP) {

        if ((unsigned)env->cc_op < CC_OP_NB)

            strcpy(cc_op_name, cc_op_str[env->cc_op]);

        else

            snprintf(cc_op_name, sizeof(cc_op_name), "[%d]", env->cc_op);

        fprintf(f, "CCS=%08x CCD=%08x CCO=%-8s\n",

                env->cc_src, env->cc_dst, cc_op_name);

    }

    if (flags & X86_DUMP_FPU) {

        fprintf(f, "ST0=%f ST1=%f ST2=%f ST3=%f\n", 

                (double)env->fpregs[0], 

                (double)env->fpregs[1], 

                (double)env->fpregs[2], 

                (double)env->fpregs[3]);

        fprintf(f, "ST4=%f ST5=%f ST6=%f ST7=%f\n", 

                (double)env->fpregs[4], 

                (double)env->fpregs[5], 

                (double)env->fpregs[7], 

                (double)env->fpregs[8]);

    }

}

/***********************************************************/

/* x86 mmu */

/* XXX: add PGE support */

/* called when cr3 or PG bit are modified */

static int last_pg_state = -1;

static uint32_t a20_mask;

int a20_enabled;

void cpu_x86_set_a20(CPUX86State *env, int a20_state)

{

    a20_state = (a20_state != 0);

    if (a20_state != a20_enabled) {

#if defined(DEBUG_MMU)

        printf("A20 update: a20=%d\n", a20_state);

#endif

        /* if the cpu is currently executing code, we must unlink it and

           all the potentially executing TB */

        cpu_interrupt(env, 0);

        /* when a20 is changed, all the MMU mappings are invalid, so

           we must flush everything */

        tlb_flush(env);

        a20_enabled = a20_state;

        if (a20_enabled)

            a20_mask = 0xffffffff;

        else

            a20_mask = 0xffefffff;

    }

}

void cpu_x86_update_cr0(CPUX86State *env)

{

    int pg_state, pe_state;

#if defined(DEBUG_MMU)

    printf("CR0 update: CR0=0x%08x\n", env->cr[0]);

#endif

    pg_state = env->cr[0] & CR0_PG_MASK;

    if (pg_state != last_pg_state) {

        tlb_flush(env);

        last_pg_state = pg_state;

    }

    /* update PE flag in hidden flags */

    pe_state = (env->cr[0] & CR0_PE_MASK);

    env->hflags = (env->hflags & ~HF_PE_MASK) | (pe_state << HF_PE_SHIFT);

    /* ensure that ADDSEG is always set in real mode */

    env->hflags |= ((pe_state ^ 1) << HF_ADDSEG_SHIFT);

}

void cpu_x86_update_cr3(CPUX86State *env)

{

    if (env->cr[0] & CR0_PG_MASK) {

#if defined(DEBUG_MMU)

        printf("CR3 update: CR3=%08x\n", env->cr[3]);

#endif

        tlb_flush(env);

    }

}

void cpu_x86_init_mmu(CPUX86State *env)

{

    a20_enabled = 1;

    a20_mask = 0xffffffff;

    last_pg_state = -1;

    cpu_x86_update_cr0(env);

}

/* XXX: also flush 4MB pages */

void cpu_x86_flush_tlb(CPUX86State *env, uint32_t addr)

{

    tlb_flush_page(env, addr);

}

/* return value:

   -1 = cannot handle fault 

   0  = nothing more to do 

   1  = generate PF fault

   2  = soft MMU activation required for this block

*/

int cpu_x86_handle_mmu_fault(CPUX86State *env, uint32_t addr, 

                             int is_write, int is_user, int is_softmmu)

{

    uint8_t *pde_ptr, *pte_ptr;

    uint32_t pde, pte, virt_addr;

    int error_code, is_dirty, prot, page_size, ret;

    unsigned long paddr, vaddr, page_offset;

#if defined(DEBUG_MMU)

    printf("MMU fault: addr=0x%08x w=%d u=%d eip=%08x\n", 

           addr, is_write, is_user, env->eip);

#endif

    if (env->user_mode_only) {

        /* user mode only emulation */

        error_code = 0;

        goto do_fault;

    }

    if (!(env->cr[0] & CR0_PG_MASK)) {

        pte = addr;

        virt_addr = addr & TARGET_PAGE_MASK;

        prot = PROT_READ | PROT_WRITE;

        page_size = 4096;

        goto do_mapping;

    }

    /* page directory entry */

    pde_ptr = phys_ram_base + 

        (((env->cr[3] & ~0xfff) + ((addr >> 20) & ~3)) & a20_mask);

    pde = ldl_raw(pde_ptr);

    if (!(pde & PG_PRESENT_MASK)) {

        error_code = 0;

        goto do_fault;

    }

    if (is_user) {

        if (!(pde & PG_USER_MASK))

            goto do_fault_protect;

        if (is_write && !(pde & PG_RW_MASK))

            goto do_fault_protect;

    } else {

        if ((env->cr[0] & CR0_WP_MASK) && (pde & PG_USER_MASK) &&

            is_write && !(pde & PG_RW_MASK)) 

            goto do_fault_protect;

    }

    /* if PSE bit is set, then we use a 4MB page */

    if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {

        is_dirty = is_write && !(pde & PG_DIRTY_MASK);

        if (!(pde & PG_ACCESSED_MASK) || is_dirty) {

            pde |= PG_ACCESSED_MASK;

            if (is_dirty)

                pde |= PG_DIRTY_MASK;

            stl_raw(pde_ptr, pde);

        }

        pte = pde & ~0x003ff000; /* align to 4MB */

        page_size = 4096 * 1024;

        virt_addr = addr & ~0x003fffff;

    } else {

        if (!(pde & PG_ACCESSED_MASK)) {

            pde |= PG_ACCESSED_MASK;

            stl_raw(pde_ptr, pde);

        }

        /* page directory entry */

        pte_ptr = phys_ram_base + 

            (((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & a20_mask);

        pte = ldl_raw(pte_ptr);

        if (!(pte & PG_PRESENT_MASK)) {

            error_code = 0;

            goto do_fault;

        }

        if (is_user) {

            if (!(pte & PG_USER_MASK))

                goto do_fault_protect;

            if (is_write && !(pte & PG_RW_MASK))

                goto do_fault_protect;

        } else {

            if ((env->cr[0] & CR0_WP_MASK) && (pte & PG_USER_MASK) &&

                is_write && !(pte & PG_RW_MASK)) 

                goto do_fault_protect;

        }

        is_dirty = is_write && !(pte & PG_DIRTY_MASK);

        if (!(pte & PG_ACCESSED_MASK) || is_dirty) {

            pte |= PG_ACCESSED_MASK;

            if (is_dirty)

                pte |= PG_DIRTY_MASK;

            stl_raw(pte_ptr, pte);

        }

        page_size = 4096;

        virt_addr = addr & ~0xfff;

    }

    /* the page can be put in the TLB */

    prot = PROT_READ;

    if (pte & PG_DIRTY_MASK) {

        /* only set write access if already dirty... otherwise wait

           for dirty access */

        if (is_user) {

            if (pte & PG_RW_MASK)

                prot |= PROT_WRITE;

        } else {

            if (!(env->cr[0] & CR0_WP_MASK) || !(pte & PG_USER_MASK) ||

                (pte & PG_RW_MASK))

                prot |= PROT_WRITE;

        }

    }

 do_mapping:

    pte = pte & a20_mask;

    /* Even if 4MB pages, we map only one 4KB page in the cache to

       avoid filling it too fast */

    page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1);

    paddr = (pte & TARGET_PAGE_MASK) + page_offset;

    vaddr = virt_addr + page_offset;

    ret = tlb_set_page(env, vaddr, paddr, prot, is_user, is_softmmu);

    return ret;

 do_fault_protect:

    error_code = PG_ERROR_P_MASK;

 do_fault:

    env->cr[2] = addr;

    env->error_code = (is_write << PG_ERROR_W_BIT) | error_code;

    if (is_user)

        env->error_code |= PG_ERROR_U_MASK;

    return 1;

}