[Qemu-devel] [PATCH] x86_64 debug registers for gdb

[Jason Wessel]

This patch fixes the registers for the 'g' and 'G' packets for the 
qemu-system-x86_64 target.  It allows gdb 6.5 to debug a linux kernel 
and get a stack back trace.

signed-off-by: address@hidden

Thanks,
Jason.

Index: qemu/gdbstub.c
===================================================================
--- qemu.orig/gdbstub.c
+++ qemu/gdbstub.c
@@ -184,9 +184,70 @@ static int put_packet(GDBState *s, char 
     }
     return 0;
 }
+#if defined(TARGET_X86_64)
+/* Defines from GDB register struct numbers */
+#define _RAX 0
+#define _RDX 1
+#define _RCX 2
+#define _RBX 3
+#define _RSI 4
+#define _RDI 5
+#define _RBP 6
+#define _RSP 7
+#define _R8  8
+#define _R9  9
+#define _R10 10
+#define _R11 11
+#define _R12 12
+#define _R13 13
+#define _R14 14
+#define _R15 15
+#define _PC  16
+#define _PS  17
 
-#if defined(TARGET_I386)
+static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
+{
+    uint64_t *registers = (uint64_t *)mem_buf;
+    int i;
+
+    registers[_RAX] = env->regs[R_EAX];
+    registers[_RBX] = env->regs[R_EBX];
+    registers[_RCX] = env->regs[R_ECX];
+    registers[_RDX] = env->regs[R_EDX];
+    registers[_RSI] = env->regs[R_ESI];
+    registers[_RDI] = env->regs[R_EDI];
+    registers[_RBP] = env->regs[R_EBP];
+    registers[_RSP] = env->regs[R_ESP];
+    for (i = 8; i < 16; i++)
+        registers[i] = env->regs[i];
+    registers[_PC] = env->eip;
+    registers[_PS] = env->eflags;
+    for(i = 0; i < 18; i++)
+        tswapl(registers[i]);
+
+    return 18 * 8;
+}
+
+static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
+{
+    uint32_t *registers = (uint32_t *)mem_buf;
+    int i;
+
+    env->regs[R_EAX] = tswapl(registers[_RAX]);
+    env->regs[R_EBX] = tswapl(registers[_RBX]);
+    env->regs[R_ECX] = tswapl(registers[_RCX]);
+    env->regs[R_EDX] = tswapl(registers[_RDX]);
+    env->regs[R_ESI] = tswapl(registers[_RSI]);
+    env->regs[R_EDI] = tswapl(registers[_RDI]);
+    env->regs[R_EBP] = tswapl(registers[_RBP]);
+    env->regs[R_ESP] = tswapl(registers[_RSP]);
+    for (i = 8; i < 16; i++)
+        env->regs[i] = tswapl(registers[i]);
+    env->eip = tswapl(registers[_PC]);
+    env->eflags = tswapl(registers[_PS]);
+}
 
+#elif defined(TARGET_I386)
 static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
 {
     uint32_t *registers = (uint32_t *)mem_buf;