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 #include "gdbstub/helpers.h"
  14
  15 uint64_t read_fcc(CPULoongArchState *env)
  16 {
  17     uint64_t ret = 0;
  18
  19     for (int i = 0; i < 8; ++i) {
  20         ret |= (uint64_t)env->cf[i] << (i * 8);
  21     }
  22
  23     return ret;
  24 }
  25
  26 void write_fcc(CPULoongArchState *env, uint64_t val)
  27 {
  28     for (int i = 0; i < 8; ++i) {
  29         env->cf[i] = (val >> (i * 8)) & 1;
  30     }
  31 }
  32
  33 int loongarch_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
  34 {
  35     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
  36     CPULoongArchState *env = &cpu->env;
  37     uint64_t val;
  38
  39     if (0 <= n && n < 32) {
  40         val = env->gpr[n];
  41     } else if (n == 32) {
  42         /* orig_a0 */
  43         val = 0;
  44     } else if (n == 33) {
  45         val = env->pc;
  46     } else if (n == 34) {
  47         val = env->CSR_BADV;
  48     }
  49
  50     if (0 <= n && n <= 34) {
  51         if (is_la64(env)) {
  52             return gdb_get_reg64(mem_buf, val);
  53         } else {
  54             return gdb_get_reg32(mem_buf, val);
  55         }
  56     }
  57     return 0;
  58 }
  59
  60 int loongarch_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
  61 {
  62     LoongArchCPU *cpu = LOONGARCH_CPU(cs);
  63     CPULoongArchState *env = &cpu->env;
  64     target_ulong tmp;
  65     int read_length;
  66     int length = 0;
  67
  68     if (is_la64(env)) {
  69         tmp = ldq_p(mem_buf);
  70         read_length = 8;
  71     } else {
  72         tmp = ldl_p(mem_buf);
  73         read_length = 4;
  74     }
  75
  76     if (0 <= n && n < 32) {
  77         env->gpr[n] = tmp;
  78         length = read_length;
  79     } else if (n == 33) {
  80         set_pc(env, tmp);
  81         length = read_length;
  82     }
  83     return length;
  84 }
  85
  86 static int loongarch_gdb_get_fpu(CPULoongArchState *env,
  87                                  GByteArray *mem_buf, int n)
  88 {
  89     if (0 <= n && n < 32) {
  90         return gdb_get_reg64(mem_buf, env->fpr[n].vreg.D(0));
  91     } else if (n == 32) {
  92         uint64_t val = read_fcc(env);
  93         return gdb_get_reg64(mem_buf, val);
  94     } else if (n == 33) {
  95         return gdb_get_reg32(mem_buf, env->fcsr0);
  96     }
  97     return 0;
  98 }
  99
 100 static int loongarch_gdb_set_fpu(CPULoongArchState *env,
 101                                  uint8_t *mem_buf, int n)
 102 {
 103     int length = 0;
 104
 105     if (0 <= n && n < 32) {
 106         env->fpr[n].vreg.D(0) = ldq_p(mem_buf);
 107         length = 8;
 108     } else if (n == 32) {
 109         uint64_t val = ldq_p(mem_buf);
 110         write_fcc(env, val);
 111         length = 8;
 112     } else if (n == 33) {
 113         env->fcsr0 = ldl_p(mem_buf);
 114         length = 4;
 115     }
 116     return length;
 117 }
 118
 119 void loongarch_cpu_register_gdb_regs_for_features(CPUState *cs)
 120 {
 121     gdb_register_coprocessor(cs, loongarch_gdb_get_fpu, loongarch_gdb_set_fpu,
 122                              41, "loongarch-fpu.xml", 0);
 123 }