target/loongarch/gdbstub.c

   1 /*
   2  * LOONGARCH gdb server stub
   3  *
   4  * Copyright (c) 2021 Loongson Technology Corporation Limited
   5  *
   6  * SPDX-License-Identifier: LGPL-2.1+
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "cpu.h"
  11 #include "internals.h"
  12 #include "exec/gdbstub.h"
  13
  14 uint64_t read_fcc(CPULoongArchState *env)
  15 {
  16     uint64_t ret = 0;
  17
  18     for (int i = 0; i < 8; ++i) {
  19         ret |= (uint64_t)env->cf[i] << (i * 8);
  20     }
  21
  22     return ret;
  23 }
  24
  25 void write_fcc(CPULoongArchState *env, uint64_t val)
  26 {
  27     for (int i = 0; i < 8; ++i) {
  28         env->cf[i] = (val >> (i * 8)) & 1;
  29     }
  30 }
  31
  32 int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
  33 {
  34     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
  35     CPULoongArchState *env = &cpu->env;
  36
  37     if (0 <= n && n < 32) {
  38         return gdb_get_regl(mem_buf, env->gpr[n]);
  39     } else if (n == 32) {
  40         /* orig_a0 */
  41         return gdb_get_regl(mem_buf, 0);
  42     } else if (n == 33) {
  43         return gdb_get_regl(mem_buf, env->pc);
  44     } else if (n == 34) {
  45         return gdb_get_regl(mem_buf, env->CSR_BADV);
  46     }
  47     return 0;
  48 }
  49
  50 int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
  51 {
  52     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
  53     CPULoongArchState *env = &cpu->env;
  54     target_ulong tmp = ldtul_p(mem_buf);
  55     int length = 0;
  56
  57     if (0 <= n && n < 32) {
  58         env->gpr[n] = tmp;
  59         length = sizeof(target_ulong);
  60     } else if (n == 33) {
  61         env->pc = tmp;
  62         length = sizeof(target_ulong);
  63     }
  64     return length;
  65 }
  66
  67 static int loongarch_gdb_get_fpu(CPULoongArchState *env,
  68                                  GByteArray *mem_buf, int n)
  69 {
  70     if (0 <= n && n < 32) {
  71         return gdb_get_reg64(mem_buf, env->fpr[n]);
  72     } else if (n == 32) {
  73         uint64_t val = read_fcc(env);
  74         return gdb_get_reg64(mem_buf, val);
  75     } else if (n == 33) {
  76         return gdb_get_reg32(mem_buf, env->fcsr0);
  77     }
  78     return 0;
  79 }
  80
  81 static int loongarch_gdb_set_fpu(CPULoongArchState *env,
  82                                  uint8_t *mem_buf, int n)
  83 {
  84     int length = 0;
  85
  86     if (0 <= n && n < 32) {
  87         env->fpr[n] = ldq_p(mem_buf);
  88         length = 8;
  89     } else if (n == 32) {
  90         uint64_t val = ldq_p(mem_buf);
  91         write_fcc(env, val);
  92         length = 8;
  93     } else if (n == 33) {
  94         env->fcsr0 = ldl_p(mem_buf);
  95         length = 4;
  96     }
  97     return length;
  98 }
  99
 100 void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
 101 {
 102     gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
 103                              41, "loongarch-fpu.xml", 0);
 104 }