/*
* RISC-V GDB Server Stub
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "exec/gdbstub.h"
#include "cpu.h"
int riscv_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (n < 32) {
return gdb_get_regl(mem_buf, env->gpr[n]);
} else if (n == 32) {
return gdb_get_regl(mem_buf, env->pc);
}
return 0;
}
int riscv_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (n == 0) {
/* discard writes to x0 */
return sizeof(target_ulong);
} else if (n < 32) {
env->gpr[n] = ldtul_p(mem_buf);
return sizeof(target_ulong);
} else if (n == 32) {
env->pc = ldtul_p(mem_buf);
return sizeof(target_ulong);
}
return 0;
}
static int riscv_gdb_get_fpu(CPURISCVState *env, GByteArray *buf, int n)
{
if (n < 32) {
if (env->misa & RVD) {
return gdb_get_reg64(buf, env->fpr[n]);
}
if (env->misa & RVF) {
return gdb_get_reg32(buf, env->fpr[n]);
}
/* there is hole between ft11 and fflags in fpu.xml */
} else if (n < 36 && n > 32) {
target_ulong val = 0;
int result;
/*
* CSR_FFLAGS is at index 1 in csr_register, and gdb says it is FP
* register 33, so we recalculate the map index.
* This also works for CSR_FRM and CSR_FCSR.
*/
result = riscv_csrrw_debug(env, n - 32, &val,
0, 0);
if (result == 0) {
return gdb_get_regl(buf, val);
}
}
return 0;
}
static int riscv_gdb_set_fpu(CPURISCVState *env, uint8_t *mem_buf, int n)
{
if (n < 32) {
env->fpr[n] = ldq_p(mem_buf); /* always 64-bit */
return sizeof(uint64_t);
/* there is hole between ft11 and fflags in fpu.xml */
} else if (n < 36 && n > 32) {
target_ulong val = ldtul_p(mem_buf);
int result;
/*
* CSR_FFLAGS is at index 1 in csr_register, and gdb says it is FP
* register 33, so we recalculate the map index.
* This also works for CSR_FRM and CSR_FCSR.
*/
result = riscv_csrrw_debug(env, n - 32, NULL,
val, -1);
if (result == 0) {
return sizeof(target_ulong);
}
}
return 0;
}
static int riscv_gdb_get_csr(CPURISCVState *env, GByteArray *buf, int n)
{
if (n < CSR_TABLE_SIZE) {
target_ulong val = 0;
int result;
result = riscv_csrrw_debug(env, n, &val, 0, 0);
if (result == 0) {
return gdb_get_regl(buf, val);
}
}
return 0;
}
static int riscv_gdb_set_csr(CPURISCVState *env, uint8_t *mem_buf, int n)
{
if (n < CSR_TABLE_SIZE) {
target_ulong val = ldtul_p(mem_buf);
int result;
result = riscv_csrrw_debug(env, n, NULL, val, -1);
if (result == 0) {
return sizeof(target_ulong);
}
}
return 0;
}
static int riscv_gdb_get_virtual(CPURISCVState *cs, GByteArray *buf, int n)
{
if (n == 0) {
#ifdef CONFIG_USER_ONLY
return gdb_get_regl(buf, 0);
#else
return gdb_get_regl(buf, cs->priv);
#endif
}
return 0;
}
static int riscv_gdb_set_virtual(CPURISCVState *cs, uint8_t *mem_buf, int n)
{
if (n == 0) {
#ifndef CONFIG_USER_ONLY
cs->priv = ldtul_p(mem_buf) & 0x3;
if (cs->priv == PRV_H) {
cs->priv = PRV_S;
}
#endif
return sizeof(target_ulong);
}
return 0;
}
static int riscv_gen_dynamic_csr_xml(CPUState *cs, int base_reg)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
GString *s = g_string_new(NULL);
riscv_csr_predicate_fn predicate;
int bitsize = riscv_cpu_is_32bit(env) ? 32 : 64;
int i;
g_string_printf(s, "<?xml version=\"1.0\"?>");
g_string_append_printf(s, "<!DOCTYPE feature SYSTEM \"gdb-target.dtd\">");
g_string_append_printf(s, "<feature name=\"org.gnu.gdb.riscv.csr\">");
for (i = 0; i < CSR_TABLE_SIZE; i++) {
predicate = csr_ops[i].predicate;
if (predicate && !predicate(env, i)) {
if (csr_ops[i].name) {
g_string_append_printf(s, "<reg name=\"%s\"", csr_ops[i].name);
} else {
g_string_append_printf(s, "<reg name=\"csr%03x\"", i);
}
g_string_append_printf(s, " bitsize=\"%d\"", bitsize);
g_string_append_printf(s, " regnum=\"%d\"/>", base_reg + i);
}
}
g_string_append_printf(s, "</feature>");
cpu->dyn_csr_xml = g_string_free(s, false);
return CSR_TABLE_SIZE;
}
void riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (env->misa & RVD) {
gdb_register_coprocessor(cs, riscv_gdb_get_fpu, riscv_gdb_set_fpu,
36, "riscv-64bit-fpu.xml", 0);
} else if (env->misa & RVF) {
gdb_register_coprocessor(cs, riscv_gdb_get_fpu, riscv_gdb_set_fpu,
36, "riscv-32bit-fpu.xml", 0);
}
#if defined(TARGET_RISCV32)
gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual,
1, "riscv-32bit-virtual.xml", 0);
#elif defined(TARGET_RISCV64)
gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual,
1, "riscv-64bit-virtual.xml", 0);
#endif
gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr,
riscv_gen_dynamic_csr_xml(cs, cs->gdb_num_regs),
"riscv-csr.xml", 0);
}
