/*
* Nios II Semihosting syscall interface.
* This code is derived from m68k-semi.c.
* The semihosting protocol implemented here is described in the
* libgloss sources:
* https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=libgloss/nios2/nios2-semi.txt;hb=HEAD
*
* Copyright (c) 2017-2019 Mentor Graphics
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that 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 "cpu.h"
#include "exec/gdbstub.h"
#include "semihosting/softmmu-uaccess.h"
#include "qemu/log.h"
#define HOSTED_EXIT 0
#define HOSTED_INIT_SIM 1
#define HOSTED_OPEN 2
#define HOSTED_CLOSE 3
#define HOSTED_READ 4
#define HOSTED_WRITE 5
#define HOSTED_LSEEK 6
#define HOSTED_RENAME 7
#define HOSTED_UNLINK 8
#define HOSTED_STAT 9
#define HOSTED_FSTAT 10
#define HOSTED_GETTIMEOFDAY 11
#define HOSTED_ISATTY 12
#define HOSTED_SYSTEM 13
static int translate_openflags(int flags)
{
int hf;
if (flags & GDB_O_WRONLY) {
hf = O_WRONLY;
} else if (flags & GDB_O_RDWR) {
hf = O_RDWR;
} else {
hf = O_RDONLY;
}
if (flags & GDB_O_APPEND) {
hf |= O_APPEND;
}
if (flags & GDB_O_CREAT) {
hf |= O_CREAT;
}
if (flags & GDB_O_TRUNC) {
hf |= O_TRUNC;
}
if (flags & GDB_O_EXCL) {
hf |= O_EXCL;
}
return hf;
}
static bool translate_stat(CPUNios2State *env, target_ulong addr,
struct stat *s)
{
struct gdb_stat *p;
p = lock_user(VERIFY_WRITE, addr, sizeof(struct gdb_stat), 0);
if (!p) {
return false;
}
p->gdb_st_dev = cpu_to_be32(s->st_dev);
p->gdb_st_ino = cpu_to_be32(s->st_ino);
p->gdb_st_mode = cpu_to_be32(s->st_mode);
p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
p->gdb_st_uid = cpu_to_be32(s->st_uid);
p->gdb_st_gid = cpu_to_be32(s->st_gid);
p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
p->gdb_st_size = cpu_to_be64(s->st_size);
#ifdef _WIN32
/* Windows stat is missing some fields. */
p->gdb_st_blksize = 0;
p->gdb_st_blocks = 0;
#else
p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
#endif
p->gdb_st_atime = cpu_to_be32(s->st_atime);
p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
unlock_user(p, addr, sizeof(struct gdb_stat));
return true;
}
static void nios2_semi_u32_cb(CPUState *cs, uint64_t ret, int err)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
target_ulong args = env->regs[R_ARG1];
if (put_user_u32(ret, args) ||
put_user_u32(err, args + 4)) {
/*
* The nios2 semihosting ABI does not provide any way to report this
* error to the guest, so the best we can do is log it in qemu.
* It is always a guest error not to pass us a valid argument block.
*/
qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
"discarded because argument block not writable\n");
}
}
static void nios2_semi_u64_cb(CPUState *cs, uint64_t ret, int err)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
target_ulong args = env->regs[R_ARG1];
if (put_user_u32(ret >> 32, args) ||
put_user_u32(ret, args + 4) ||
put_user_u32(err, args + 8)) {
/* No way to report this via nios2 semihosting ABI; just log it */
qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
"discarded because argument block not writable\n");
}
}
/*
* Read the input value from the argument block; fail the semihosting
* call if the memory read fails.
*/
#define GET_ARG(n) do { \
if (get_user_ual(arg ## n, args + (n) * 4)) { \
result = -1; \
errno = EFAULT; \
goto failed; \
} \
} while (0)
void do_nios2_semihosting(CPUNios2State *env)
{
CPUState *cs = env_cpu(env);
int nr;
uint32_t args;
target_ulong arg0, arg1, arg2, arg3;
void *p;
void *q;
uint32_t len;
uint32_t result;
nr = env->regs[R_ARG0];
args = env->regs[R_ARG1];
switch (nr) {
case HOSTED_EXIT:
gdb_exit(env->regs[R_ARG0]);
exit(env->regs[R_ARG0]);
case HOSTED_OPEN:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
GET_ARG(3);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "open,%s,%x,%x", arg0, (int)arg1,
arg2, arg3);
return;
} else {
p = lock_user_string(arg0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = open(p, translate_openflags(arg2), arg3);
unlock_user(p, arg0, 0);
}
}
break;
case HOSTED_CLOSE:
{
/* Ignore attempts to close stdin/out/err. */
GET_ARG(0);
int fd = arg0;
if (fd > 2) {
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "close,%x", arg0);
return;
} else {
result = close(fd);
}
} else {
result = 0;
}
break;
}
case HOSTED_READ:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
len = arg2;
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "read,%x,%x,%x",
arg0, arg1, len);
return;
} else {
p = lock_user(VERIFY_WRITE, arg1, len, 0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = read(arg0, p, len);
unlock_user(p, arg1, len);
}
}
break;
case HOSTED_WRITE:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
len = arg2;
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "write,%x,%x,%x",
arg0, arg1, len);
return;
} else {
p = lock_user(VERIFY_READ, arg1, len, 1);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = write(arg0, p, len);
unlock_user(p, arg0, 0);
}
}
break;
case HOSTED_LSEEK:
{
uint64_t off;
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
GET_ARG(3);
off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u64_cb, "lseek,%x,%lx,%x",
arg0, off, arg3);
} else {
off = lseek(arg0, off, arg3);
nios2_semi_u64_cb(cs, off, errno);
}
return;
}
case HOSTED_RENAME:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
GET_ARG(3);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "rename,%s,%s",
arg0, (int)arg1, arg2, (int)arg3);
return;
} else {
p = lock_user_string(arg0);
q = lock_user_string(arg2);
if (!p || !q) {
result = -1;
errno = EFAULT;
} else {
result = rename(p, q);
}
unlock_user(p, arg0, 0);
unlock_user(q, arg2, 0);
}
break;
case HOSTED_UNLINK:
GET_ARG(0);
GET_ARG(1);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "unlink,%s",
arg0, (int)arg1);
return;
} else {
p = lock_user_string(arg0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = unlink(p);
unlock_user(p, arg0, 0);
}
}
break;
case HOSTED_STAT:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "stat,%s,%x",
arg0, (int)arg1, arg2);
return;
} else {
struct stat s;
p = lock_user_string(arg0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = stat(p, &s);
unlock_user(p, arg0, 0);
}
if (result == 0 && !translate_stat(env, arg2, &s)) {
result = -1;
errno = EFAULT;
}
}
break;
case HOSTED_FSTAT:
GET_ARG(0);
GET_ARG(1);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "fstat,%x,%x",
arg0, arg1);
return;
} else {
struct stat s;
result = fstat(arg0, &s);
if (result == 0 && !translate_stat(env, arg1, &s)) {
result = -1;
errno = EFAULT;
}
}
break;
case HOSTED_GETTIMEOFDAY:
/* Only the tv parameter is used. tz is assumed NULL. */
GET_ARG(0);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "gettimeofday,%x,%x",
arg0, 0);
return;
} else {
struct gdb_timeval *p;
int64_t rt = g_get_real_time();
p = lock_user(VERIFY_WRITE, arg0, sizeof(struct gdb_timeval), 0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = 0;
p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
unlock_user(p, arg0, sizeof(struct gdb_timeval));
}
}
break;
case HOSTED_ISATTY:
GET_ARG(0);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "isatty,%x", arg0);
return;
} else {
result = isatty(arg0);
}
break;
case HOSTED_SYSTEM:
GET_ARG(0);
GET_ARG(1);
if (use_gdb_syscalls()) {
gdb_do_syscall(nios2_semi_u32_cb, "system,%s",
arg0, (int)arg1);
return;
} else {
p = lock_user_string(arg0);
if (!p) {
result = -1;
errno = EFAULT;
} else {
result = system(p);
unlock_user(p, arg0, 0);
}
}
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: unsupported "
"semihosting syscall %d\n", nr);
result = 0;
}
failed:
nios2_semi_u32_cb(cs, result, errno);
}
