Archipelago » qemu

#ifdef USE_CODE_COPY

#include <unistd.h>

#include <asm/ldt.h>

#include <linux/unistd.h>

#include <linux/version.h>

int modify_ldt(int func, void *ptr, unsigned long bytecount)

{

	return syscall(__NR_modify_ldt, func, ptr, bytecount);

}

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 66)

#define modify_ldt_ldt_s user_desc

#endif

#endif /* USE_CODE_COPY */

#ifdef USE_CODE_COPY

    /* testing code for code copy case */

    {

        struct modify_ldt_ldt_s ldt;

        ldt.entry_number = 1;

        ldt.base_addr = (unsigned long)env;

        ldt.limit = (sizeof(CPUState) + 0xfff) >> 12;

        ldt.seg_32bit = 1;

        ldt.contents = MODIFY_LDT_CONTENTS_DATA;

        ldt.read_exec_only = 0;

        ldt.limit_in_pages = 1;

        ldt.seg_not_present = 0;

        ldt.useable = 1;

        modify_ldt(1, &ldt, sizeof(ldt)); /* write ldt entry */

        asm volatile ("movl %0, %%fs" : : "r" ((1 << 3) | 7));

    }

#endif

#if defined(USE_CODE_COPY)

struct fpstate {

    uint16_t fpuc;

    uint16_t dummy1;

    uint16_t fpus;

    uint16_t dummy2;

    uint16_t fptag;

    uint16_t dummy3;

    uint32_t fpip;

    uint32_t fpcs;

    uint32_t fpoo;

    uint32_t fpos;

    uint8_t fpregs1[8 * 10];

};

void restore_native_fp_state(CPUState *env)

{

    int fptag, i, j;

    struct fpstate fp1, *fp = &fp1;

    fp->fpuc = env->fpuc;

    fp->fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;

    fptag = 0;

    for (i=7; i>=0; i--) {

	fptag <<= 2;

	if (env->fptags[i]) {

            fptag |= 3;

        } else {

            /* the FPU automatically computes it */

        }

    }

    fp->fptag = fptag;

    j = env->fpstt;

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

        memcpy(&fp->fpregs1[i * 10], &env->fpregs[j].d, 10);

        j = (j + 1) & 7;

    }

    asm volatile ("frstor %0" : "=m" (*fp));

    env->native_fp_regs = 1;

}

void save_native_fp_state(CPUState *env)

{

    int fptag, i, j;

    uint16_t fpuc;

    struct fpstate fp1, *fp = &fp1;

    asm volatile ("fsave %0" : : "m" (*fp));

    env->fpuc = fp->fpuc;

    env->fpstt = (fp->fpus >> 11) & 7;

    env->fpus = fp->fpus & ~0x3800;

    fptag = fp->fptag;

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

        env->fptags[i] = ((fptag & 3) == 3);

        fptag >>= 2;

    }

    j = env->fpstt;

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

        memcpy(&env->fpregs[j].d, &fp->fpregs1[i * 10], 10);

        j = (j + 1) & 7;

    }

    /* we must restore the default rounding state */

    /* XXX: we do not restore the exception state */

    fpuc = 0x037f | (env->fpuc & (3 << 10));

    asm volatile("fldcw %0" : : "m" (fpuc));

    env->native_fp_regs = 0;

}

#endif