Archipelago » qemu

/*

 * x86 gdb server stub

 *

 * Copyright (c) 2003-2005 Fabrice Bellard

 * Copyright (c) 2013 SUSE LINUX Products GmbH

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include "qemu-common.h"

#include "exec/gdbstub.h"

#ifdef TARGET_X86_64

static const int gpr_map[16] = {

    R_EAX, R_EBX, R_ECX, R_EDX, R_ESI, R_EDI, R_EBP, R_ESP,

    8, 9, 10, 11, 12, 13, 14, 15

};

#else

#define gpr_map gpr_map32

#endif

static const int gpr_map32[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };

#define IDX_IP_REG      CPU_NB_REGS

#define IDX_FLAGS_REG   (IDX_IP_REG + 1)

#define IDX_SEG_REGS    (IDX_FLAGS_REG + 1)

#define IDX_FP_REGS     (IDX_SEG_REGS + 6)

#define IDX_XMM_REGS    (IDX_FP_REGS + 16)

#define IDX_MXCSR_REG   (IDX_XMM_REGS + CPU_NB_REGS)

int x86_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)

{

    X86CPU *cpu = X86_CPU(cs);

    CPUX86State *env = &cpu->env;

    if (n < CPU_NB_REGS) {

        if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {

            return gdb_get_reg64(mem_buf, env->regs[gpr_map[n]]);

        } else if (n < CPU_NB_REGS32) {

            return gdb_get_reg32(mem_buf, env->regs[gpr_map32[n]]);

        }

    } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {

#ifdef USE_X86LDOUBLE

        /* FIXME: byteswap float values - after fixing fpregs layout. */

        memcpy(mem_buf, &env->fpregs[n - IDX_FP_REGS], 10);

#else

        memset(mem_buf, 0, 10);

#endif

        return 10;

    } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {

        n -= IDX_XMM_REGS;

        if (n < CPU_NB_REGS32 ||

            (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK)) {

            stq_p(mem_buf, env->xmm_regs[n].XMM_Q(0));

            stq_p(mem_buf + 8, env->xmm_regs[n].XMM_Q(1));

            return 16;

        }

    } else {

        switch (n) {

        case IDX_IP_REG:

            if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {

                return gdb_get_reg64(mem_buf, env->eip);

            } else {

                return gdb_get_reg32(mem_buf, env->eip);

            }

        case IDX_FLAGS_REG:

            return gdb_get_reg32(mem_buf, env->eflags);

        case IDX_SEG_REGS:

            return gdb_get_reg32(mem_buf, env->segs[R_CS].selector);

        case IDX_SEG_REGS + 1:

            return gdb_get_reg32(mem_buf, env->segs[R_SS].selector);

        case IDX_SEG_REGS + 2:

            return gdb_get_reg32(mem_buf, env->segs[R_DS].selector);

        case IDX_SEG_REGS + 3:

            return gdb_get_reg32(mem_buf, env->segs[R_ES].selector);

        case IDX_SEG_REGS + 4:

            return gdb_get_reg32(mem_buf, env->segs[R_FS].selector);

        case IDX_SEG_REGS + 5:

            return gdb_get_reg32(mem_buf, env->segs[R_GS].selector);

        case IDX_FP_REGS + 8:

            return gdb_get_reg32(mem_buf, env->fpuc);

        case IDX_FP_REGS + 9:

            return gdb_get_reg32(mem_buf, (env->fpus & ~0x3800) |

                                          (env->fpstt & 0x7) << 11);

        case IDX_FP_REGS + 10:

            return gdb_get_reg32(mem_buf, 0); /* ftag */

        case IDX_FP_REGS + 11:

            return gdb_get_reg32(mem_buf, 0); /* fiseg */

        case IDX_FP_REGS + 12:

            return gdb_get_reg32(mem_buf, 0); /* fioff */

        case IDX_FP_REGS + 13:

            return gdb_get_reg32(mem_buf, 0); /* foseg */

        case IDX_FP_REGS + 14:

            return gdb_get_reg32(mem_buf, 0); /* fooff */

        case IDX_FP_REGS + 15:

            return gdb_get_reg32(mem_buf, 0); /* fop */

        case IDX_MXCSR_REG:

            return gdb_get_reg32(mem_buf, env->mxcsr);

        }

    }

    return 0;

}

static int x86_cpu_gdb_load_seg(X86CPU *cpu, int sreg, uint8_t *mem_buf)

{

    CPUX86State *env = &cpu->env;

    uint16_t selector = ldl_p(mem_buf);

    if (selector != env->segs[sreg].selector) {

#if defined(CONFIG_USER_ONLY)

        cpu_x86_load_seg(env, sreg, selector);

#else

        unsigned int limit, flags;

        target_ulong base;

        if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {

            base = selector << 4;

            limit = 0xffff;

            flags = 0;

        } else {

            if (!cpu_x86_get_descr_debug(env, selector, &base, &limit,

                                         &flags)) {

                return 4;

            }

        }

        cpu_x86_load_seg_cache(env, sreg, selector, base, limit, flags);

#endif

    }

    return 4;

}

int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)

{

    X86CPU *cpu = X86_CPU(cs);

    CPUX86State *env = &cpu->env;

    uint32_t tmp;

    if (n < CPU_NB_REGS) {

        if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {

            env->regs[gpr_map[n]] = ldtul_p(mem_buf);

            return sizeof(target_ulong);

        } else if (n < CPU_NB_REGS32) {

            n = gpr_map32[n];

            env->regs[n] &= ~0xffffffffUL;

            env->regs[n] |= (uint32_t)ldl_p(mem_buf);

            return 4;

        }

    } else if (n >= IDX_FP_REGS && n < IDX_FP_REGS + 8) {

#ifdef USE_X86LDOUBLE

        /* FIXME: byteswap float values - after fixing fpregs layout. */

        memcpy(&env->fpregs[n - IDX_FP_REGS], mem_buf, 10);

#endif

        return 10;

    } else if (n >= IDX_XMM_REGS && n < IDX_XMM_REGS + CPU_NB_REGS) {

        n -= IDX_XMM_REGS;

        if (n < CPU_NB_REGS32 ||

            (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK)) {

            env->xmm_regs[n].XMM_Q(0) = ldq_p(mem_buf);

            env->xmm_regs[n].XMM_Q(1) = ldq_p(mem_buf + 8);

            return 16;

        }

    } else {

        switch (n) {

        case IDX_IP_REG:

            if (TARGET_LONG_BITS == 64 && env->hflags & HF_CS64_MASK) {

                env->eip = ldq_p(mem_buf);

                return 8;

            } else {

                env->eip &= ~0xffffffffUL;

                env->eip |= (uint32_t)ldl_p(mem_buf);

                return 4;

            }

        case IDX_FLAGS_REG:

            env->eflags = ldl_p(mem_buf);

            return 4;

        case IDX_SEG_REGS:

            return x86_cpu_gdb_load_seg(cpu, R_CS, mem_buf);

        case IDX_SEG_REGS + 1:

            return x86_cpu_gdb_load_seg(cpu, R_SS, mem_buf);

        case IDX_SEG_REGS + 2:

            return x86_cpu_gdb_load_seg(cpu, R_DS, mem_buf);

        case IDX_SEG_REGS + 3:

            return x86_cpu_gdb_load_seg(cpu, R_ES, mem_buf);

        case IDX_SEG_REGS + 4:

            return x86_cpu_gdb_load_seg(cpu, R_FS, mem_buf);

        case IDX_SEG_REGS + 5:

            return x86_cpu_gdb_load_seg(cpu, R_GS, mem_buf);

        case IDX_FP_REGS + 8:

            env->fpuc = ldl_p(mem_buf);

            return 4;

        case IDX_FP_REGS + 9:

            tmp = ldl_p(mem_buf);

            env->fpstt = (tmp >> 11) & 7;

            env->fpus = tmp & ~0x3800;

            return 4;

        case IDX_FP_REGS + 10: /* ftag */

            return 4;

        case IDX_FP_REGS + 11: /* fiseg */

            return 4;

        case IDX_FP_REGS + 12: /* fioff */

            return 4;

        case IDX_FP_REGS + 13: /* foseg */

            return 4;

        case IDX_FP_REGS + 14: /* fooff */

            return 4;

        case IDX_FP_REGS + 15: /* fop */

            return 4;

        case IDX_MXCSR_REG:

            env->mxcsr = ldl_p(mem_buf);

            return 4;

        }

    }

    /* Unrecognised register.  */

    return 0;

}