LXR qemu/target/avr/gdbstub.c

   1/*
   2 * QEMU AVR gdbstub
   3 *
   4 * Copyright (c) 2016-2020 Michael Rolnik
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2.1 of the License, or (at your option) any later version.
  10 *
  11 * This library is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * Lesser General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU Lesser General Public
  17 * License along with this library; if not, see
  18 * <http://www.gnu.org/licenses/lgpl-2.1.html>
  19 */
  20
  21#include "qemu/osdep.h"
  22#include "exec/gdbstub.h"
  23
  24int avr_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
  25{
  26    AVRCPU *cpu = AVR_CPU(cs);
  27    CPUAVRState *env = &cpu->env;
  28
  29    /*  R */
  30    if (n < 32) {
  31        return gdb_get_reg8(mem_buf, env->r[n]);
  32    }
  33
  34    /*  SREG */
  35    if (n == 32) {
  36        uint8_t sreg = cpu_get_sreg(env);
  37
  38        return gdb_get_reg8(mem_buf, sreg);
  39    }
  40
  41    /*  SP */
  42    if (n == 33) {
  43        return gdb_get_reg16(mem_buf, env->sp & 0x0000ffff);
  44    }
  45
  46    /*  PC */
  47    if (n == 34) {
  48        return gdb_get_reg32(mem_buf, env->pc_w * 2);
  49    }
  50
  51    return 0;
  52}
  53
  54int avr_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
  55{
  56    AVRCPU *cpu = AVR_CPU(cs);
  57    CPUAVRState *env = &cpu->env;
  58
  59    /*  R */
  60    if (n < 32) {
  61        env->r[n] = *mem_buf;
  62        return 1;
  63    }
  64
  65    /*  SREG */
  66    if (n == 32) {
  67        cpu_set_sreg(env, *mem_buf);
  68        return 1;
  69    }
  70
  71    /*  SP */
  72    if (n == 33) {
  73        env->sp = lduw_p(mem_buf);
  74        return 2;
  75    }
  76
  77    /*  PC */
  78    if (n == 34) {
  79        env->pc_w = ldl_p(mem_buf) / 2;
  80        return 4;
  81    }
  82
  83    return 0;
  84}
  85
  86vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr)
  87{
  88    /*
  89     * This is due to some strange GDB behavior
  90     * Let's assume main has address 0x100:
  91     * b main   - sets breakpoint at address 0x00000100 (code)
  92     * b *0x100 - sets breakpoint at address 0x00800100 (data)
  93     *
  94     * Force all breakpoints into code space.
  95     */
  96    return addr % OFFSET_DATA;
  97}
  98