/*
* 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/syscalls.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 host_to_gdb_errno(int err)
{
#define E(X) case E##X: return GDB_E##X
switch (err) {
E(PERM);
E(NOENT);
E(INTR);
E(BADF);
E(ACCES);
E(FAULT);
E(BUSY);
E(EXIST);
E(NODEV);
E(NOTDIR);
E(ISDIR);
E(INVAL);
E(NFILE);
E(MFILE);
E(FBIG);
E(NOSPC);
E(SPIPE);
E(ROFS);
E(NAMETOOLONG);
default:
return GDB_EUNKNOWN;
}
#undef E
}
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(host_to_gdb_errno(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(host_to_gdb_errno(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)) { \
goto failed; \
} \
} while (0)
#define GET_ARG64(n) do { \
if (get_user_ual(arg ## n, args + (n) * 4)) { \
goto failed64; \
} \
} while (0)
void do_nios2_semihosting(CPUNios2State *env)
{
CPUState *cs = env_cpu(env);
int nr;
uint32_t args;
target_ulong arg0, arg1, arg2, arg3;
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);
semihost_sys_open(cs, nios2_semi_u32_cb, arg0, arg1, arg2, arg3);
break;
case HOSTED_CLOSE:
GET_ARG(0);
semihost_sys_close(cs, nios2_semi_u32_cb, arg0);
break;
case HOSTED_READ:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
semihost_sys_read(cs, nios2_semi_u32_cb, arg0, arg1, arg2);
break;
case HOSTED_WRITE:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
semihost_sys_write(cs, nios2_semi_u32_cb, arg0, arg1, arg2);
break;
case HOSTED_LSEEK:
GET_ARG64(0);
GET_ARG64(1);
GET_ARG64(2);
GET_ARG64(3);
semihost_sys_lseek(cs, nios2_semi_u64_cb, arg0,
deposit64(arg2, arg1, 32, 32), arg3);
break;
case HOSTED_RENAME:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
GET_ARG(3);
semihost_sys_rename(cs, nios2_semi_u32_cb, arg0, arg1, arg2, arg3);
break;
case HOSTED_UNLINK:
GET_ARG(0);
GET_ARG(1);
semihost_sys_remove(cs, nios2_semi_u32_cb, arg0, arg1);
break;
case HOSTED_STAT:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
semihost_sys_stat(cs, nios2_semi_u32_cb, arg0, arg1, arg2);
break;
case HOSTED_FSTAT:
GET_ARG(0);
GET_ARG(1);
semihost_sys_fstat(cs, nios2_semi_u32_cb, arg0, arg1);
break;
case HOSTED_GETTIMEOFDAY:
GET_ARG(0);
GET_ARG(1);
semihost_sys_gettimeofday(cs, nios2_semi_u32_cb, arg0, arg1);
break;
case HOSTED_ISATTY:
GET_ARG(0);
semihost_sys_isatty(cs, nios2_semi_u32_cb, arg0);
break;
case HOSTED_SYSTEM:
GET_ARG(0);
GET_ARG(1);
semihost_sys_system(cs, nios2_semi_u32_cb, arg0, arg1);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: unsupported "
"semihosting syscall %d\n", nr);
nios2_semi_u32_cb(cs, -1, ENOSYS);
break;
failed:
nios2_semi_u32_cb(cs, -1, EFAULT);
break;
failed64:
nios2_semi_u64_cb(cs, -1, EFAULT);
break;
}
}
