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-i386.h"

#include "exec.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",

    "MUL",

    "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;

    char cc_op_name[32];

    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]\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' : '-');

    fprintf(f, "CS=%04x SS=%04x DS=%04x ES=%04x FS=%04x GS=%04x\n",

            env->segs[R_CS].selector,

            env->segs[R_SS].selector,

            env->segs[R_DS].selector,

            env->segs[R_ES].selector,

            env->segs[R_FS].selector,

            env->segs[R_GS].selector);

    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 int last_pe_state = 0;

int phys_ram_size;

int phys_ram_fd;

uint8_t *phys_ram_base;

void cpu_x86_update_cr0(CPUX86State *env)

{

    int pg_state, pe_state;

#ifdef 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) {

        page_unmap();

        tlb_flush(env);

        last_pg_state = pg_state;

    }

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

    if (last_pe_state != pe_state) {

        tb_flush();

        last_pe_state = pe_state;

    }

}

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

        page_unmap();

        tlb_flush(env);

    }

}

void cpu_x86_init_mmu(CPUX86State *env)

{

    last_pg_state = -1;

    cpu_x86_update_cr0(env);

}

/* XXX: also flush 4MB pages */

void cpu_x86_flush_tlb(CPUX86State *env, uint32_t addr)

{

    int flags;

    unsigned long virt_addr;

    tlb_flush_page(env, addr);

    flags = page_get_flags(addr);

    if (flags & PAGE_VALID) {

        virt_addr = addr & ~0xfff;

        munmap((void *)virt_addr, 4096);

        page_set_flags(virt_addr, virt_addr + 4096, 0);

    }

}

/* 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)

{

    uint8_t *pde_ptr, *pte_ptr;

    uint32_t pde, pte, virt_addr;

    int cpl, error_code, is_dirty, is_user, prot, page_size, ret;

    unsigned long pd;

    cpl = env->hflags & HF_CPL_MASK;

    is_user = (cpl == 3);

#ifdef 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 & ~0xfff;

        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));

    pde = ldl(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)) {

            pde |= PG_ACCESSED_MASK;

            if (is_dirty)

                pde |= PG_DIRTY_MASK;

            stl(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(pde_ptr, pde);

        }

        /* page directory entry */

        pte_ptr = phys_ram_base + ((pde & ~0xfff) + ((addr >> 10) & 0xffc));

        pte = ldl(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(pte_ptr, pte);

        }

        page_size = 4096;

        virt_addr = addr & ~0xfff;

    }

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

    prot = PROT_READ;

    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:

    if (env->hflags & HF_SOFTMMU_MASK) {

        unsigned long paddr, vaddr, address, addend, page_offset;

        int index;

        /* software MMU case. Even if 4MB pages, we map only one 4KB

           page in the cache to avoid filling it too fast */

        page_offset = (addr & ~0xfff) & (page_size - 1);

        paddr = (pte & ~0xfff) + page_offset;

        vaddr = virt_addr + page_offset;

        index = (addr >> 12) & (CPU_TLB_SIZE - 1);

        pd = physpage_find(paddr);

        if (pd & 0xfff) {

            /* IO memory case */

            address = vaddr | pd;

            addend = paddr;

        } else {

            /* standard memory */

            address = vaddr;

            addend = (unsigned long)phys_ram_base + pd;

        }

        addend -= vaddr;

        env->tlb_read[is_user][index].address = address;

        env->tlb_read[is_user][index].addend = addend;

        if (prot & PROT_WRITE) {

            env->tlb_write[is_user][index].address = address;

            env->tlb_write[is_user][index].addend = addend;

        }

    }

    ret = 0;

    /* XXX: incorrect for 4MB pages */

    pd = physpage_find(pte & ~0xfff);

    if ((pd & 0xfff) != 0) {

        /* IO access: no mapping is done as it will be handled by the

           soft MMU */

        if (!(env->hflags & HF_SOFTMMU_MASK))

            ret = 2;

    } else {

        void *map_addr;

        map_addr = mmap((void *)virt_addr, page_size, prot, 

                        MAP_SHARED | MAP_FIXED, phys_ram_fd, pd);

        if (map_addr == MAP_FAILED) {

            fprintf(stderr, 

                    "mmap failed when mapped physical address 0x%08x to virtual address 0x%08x\n",

                    pte & ~0xfff, virt_addr);

            exit(1);

        }

#ifdef DEBUG_MMU

        printf("mmaping 0x%08x to virt 0x%08x pse=%d\n", 

               pte & ~0xfff, virt_addr, (page_size != 4096));

#endif

        page_set_flags(virt_addr, virt_addr + page_size, 

                       PAGE_VALID | PAGE_EXEC | prot);

    }

    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;

}