Hi, earlier this week I needed to use gdb with QEMU to debug some software of mine that runs in a 64-bit code segment. But gdb only gave me nonsense data because QEMU sent it a normal i386 register dump.
The following patch fixes cpu_gdb_read_registers() so that it works for 64-bit code segments. It's based on the 32-bit version and I haven't verified if the byte swapping and floating point stuff is correct. cpu_gdb_write_registers() also needs to be fixed, but I don't have any personal need for it right now and I also don't understand why it loads the segment registers only when CONFIG_USER_ONLY is defined. Seems to me like it should be the other way around, so I don't dare suggest a patch. Index: gdbstub.c =================================================================== RCS file: /sources/qemu/qemu/gdbstub.c,v retrieving revision 1.63 diff -u -r1.63 gdbstub.c --- gdbstub.c 6 Sep 2007 00:18:13 -0000 1.63 +++ gdbstub.c 6 Sep 2007 17:22:51 -0000 @@ -225,8 +225,54 @@ static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf) { - uint32_t *registers = (uint32_t *)mem_buf; int i, fpus; +#ifdef TARGET_X86_64 + if (env->hflags & HF_CS64_MASK) { + /* This corresponds with amd64_register_info[] in gdb/amd64-tdep.c */ + uint64_t *registers = (uint64_t *)mem_buf; + + registers[0] = tswap64(env->regs[R_EAX]); + registers[1] = tswap64(env->regs[R_EBX]); + registers[2] = tswap64(env->regs[R_ECX]); + registers[3] = tswap64(env->regs[R_EDX]); + registers[4] = tswap64(env->regs[R_ESI]); + registers[5] = tswap64(env->regs[R_EDI]); + registers[6] = tswap64(env->regs[R_EBP]); + registers[7] = tswap64(env->regs[R_ESP]); + for(i = 8; i < 16; i++) { + registers[i] = tswap64(env->regs[i]); + } + registers[16] = tswap64(env->eip); + uint32_t *registers32 = (uint32_t*) ®isters[17]; + registers32[0] = tswap32(env->eflags); + registers32[1] = tswap32(env->segs[R_CS].selector); + registers32[2] = tswap32(env->segs[R_SS].selector); + registers32[3] = tswap32(env->segs[R_DS].selector); + registers32[4] = tswap32(env->segs[R_ES].selector); + registers32[5] = tswap32(env->segs[R_FS].selector); + registers32[6] = tswap32(env->segs[R_GS].selector); + /* XXX: convert floats */ + for(i = 0; i < 8; i++) { + memcpy(mem_buf + 16 * 8 + 7 * 4 + i * 10, &env->fpregs[i], 10); + } + registers32[27] = tswap32(env->fpuc); /* fctrl */ + fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11; + registers32[28] = tswap32(fpus); /* fstat */ + registers32[29] = 0; /* ftag */ + registers32[30] = 0; /* fiseg */ + registers32[31] = 0; /* fioff */ + registers32[32] = 0; /* foseg */ + registers32[33] = 0; /* fooff */ + registers32[34] = 0; /* fop */ + for(i = 0; i < 16; i++) { + memcpy(mem_buf + 16 * 8 + 35 * 4 + i * 16, &env->xmm_regs[i], 16); + } + registers32[99] = tswap32(env->mxcsr); + + return 8 * 17 + 4 * 7 + 10 * 8 + 4 * 8 + 16 * 16 + 4; + } +#endif + uint32_t *registers = (uint32_t *)mem_buf; for(i = 0; i < 8; i++) { registers[i] = env->regs[i]; -- Göran Weinholt <[EMAIL PROTECTED]> I was making donuts and now I'm on a bus!