qemu/hw/mips/mipssim.c
Pavel Dovgalyuk a4374f86dc hw/mips: Remove exit(1) in case of missing ROM
This patch updates MIPS-based machines to allow starting them without ROM.
In this case CPU starts to execute instructions from the empty memory,
but QEMU allows introspecting the machine configuration.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <159531210571.24117.231100997794891819.stgit@pasha-ThinkPad-X280>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2020-10-17 13:59:40 +02:00

248 lines
8.0 KiB
C

/*
* QEMU/mipssim emulation
*
* Emulates a very simple machine model similar to the one used by the
* proprietary MIPS emulator.
*
* Copyright (c) 2007 Thiemo Seufer
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "cpu.h"
#include "hw/clock.h"
#include "hw/mips/mips.h"
#include "hw/mips/cpudevs.h"
#include "hw/char/serial.h"
#include "hw/isa/isa.h"
#include "net/net.h"
#include "sysemu/sysemu.h"
#include "hw/boards.h"
#include "hw/mips/bios.h"
#include "hw/loader.h"
#include "elf.h"
#include "hw/sysbus.h"
#include "hw/qdev-properties.h"
#include "exec/address-spaces.h"
#include "qemu/error-report.h"
#include "sysemu/qtest.h"
#include "sysemu/reset.h"
static struct _loaderparams {
int ram_size;
const char *kernel_filename;
const char *kernel_cmdline;
const char *initrd_filename;
} loaderparams;
typedef struct ResetData {
MIPSCPU *cpu;
uint64_t vector;
} ResetData;
static int64_t load_kernel(void)
{
int64_t entry, kernel_high, initrd_size;
long kernel_size;
ram_addr_t initrd_offset;
int big_endian;
#ifdef TARGET_WORDS_BIGENDIAN
big_endian = 1;
#else
big_endian = 0;
#endif
kernel_size = load_elf(loaderparams.kernel_filename, NULL,
cpu_mips_kseg0_to_phys, NULL,
(uint64_t *)&entry, NULL,
(uint64_t *)&kernel_high, NULL, big_endian,
EM_MIPS, 1, 0);
if (kernel_size < 0) {
error_report("could not load kernel '%s': %s",
loaderparams.kernel_filename,
load_elf_strerror(kernel_size));
exit(1);
}
/* load initrd */
initrd_size = 0;
initrd_offset = 0;
if (loaderparams.initrd_filename) {
initrd_size = get_image_size(loaderparams.initrd_filename);
if (initrd_size > 0) {
initrd_offset = ROUND_UP(kernel_high, INITRD_PAGE_SIZE);
if (initrd_offset + initrd_size > loaderparams.ram_size) {
error_report("memory too small for initial ram disk '%s'",
loaderparams.initrd_filename);
exit(1);
}
initrd_size = load_image_targphys(loaderparams.initrd_filename,
initrd_offset, loaderparams.ram_size - initrd_offset);
}
if (initrd_size == (target_ulong) -1) {
error_report("could not load initial ram disk '%s'",
loaderparams.initrd_filename);
exit(1);
}
}
return entry;
}
static void main_cpu_reset(void *opaque)
{
ResetData *s = (ResetData *)opaque;
CPUMIPSState *env = &s->cpu->env;
cpu_reset(CPU(s->cpu));
env->active_tc.PC = s->vector & ~(target_ulong)1;
if (s->vector & 1) {
env->hflags |= MIPS_HFLAG_M16;
}
}
static void mipsnet_init(int base, qemu_irq irq, NICInfo *nd)
{
DeviceState *dev;
SysBusDevice *s;
dev = qdev_new("mipsnet");
qdev_set_nic_properties(dev, nd);
s = SYS_BUS_DEVICE(dev);
sysbus_realize_and_unref(s, &error_fatal);
sysbus_connect_irq(s, 0, irq);
memory_region_add_subregion(get_system_io(),
base,
sysbus_mmio_get_region(s, 0));
}
static void
mips_mipssim_init(MachineState *machine)
{
const char *kernel_filename = machine->kernel_filename;
const char *kernel_cmdline = machine->kernel_cmdline;
const char *initrd_filename = machine->initrd_filename;
char *filename;
MemoryRegion *address_space_mem = get_system_memory();
MemoryRegion *isa = g_new(MemoryRegion, 1);
MemoryRegion *bios = g_new(MemoryRegion, 1);
Clock *cpuclk;
MIPSCPU *cpu;
CPUMIPSState *env;
ResetData *reset_info;
int bios_size;
cpuclk = clock_new(OBJECT(machine), "cpu-refclk");
#ifdef TARGET_MIPS64
clock_set_hz(cpuclk, 6000000); /* 6 MHz */
#else
clock_set_hz(cpuclk, 12000000); /* 12 MHz */
#endif
/* Init CPUs. */
cpu = mips_cpu_create_with_clock(machine->cpu_type, cpuclk);
env = &cpu->env;
reset_info = g_malloc0(sizeof(ResetData));
reset_info->cpu = cpu;
reset_info->vector = env->active_tc.PC;
qemu_register_reset(main_cpu_reset, reset_info);
/* Allocate RAM. */
memory_region_init_rom(bios, NULL, "mips_mipssim.bios", BIOS_SIZE,
&error_fatal);
memory_region_add_subregion(address_space_mem, 0, machine->ram);
/* Map the BIOS / boot exception handler. */
memory_region_add_subregion(address_space_mem, 0x1fc00000LL, bios);
/* Load a BIOS / boot exception handler image. */
filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name ?: BIOS_FILENAME);
if (filename) {
bios_size = load_image_targphys(filename, 0x1fc00000LL, BIOS_SIZE);
g_free(filename);
} else {
bios_size = -1;
}
if ((bios_size < 0 || bios_size > BIOS_SIZE) &&
bios_name && !qtest_enabled()) {
/* Bail out if we have neither a kernel image nor boot vector code. */
error_report("Could not load MIPS bios '%s'", bios_name);
exit(1);
} else {
/* We have a boot vector start address. */
env->active_tc.PC = (target_long)(int32_t)0xbfc00000;
}
if (kernel_filename) {
loaderparams.ram_size = machine->ram_size;
loaderparams.kernel_filename = kernel_filename;
loaderparams.kernel_cmdline = kernel_cmdline;
loaderparams.initrd_filename = initrd_filename;
reset_info->vector = load_kernel();
}
/* Init CPU internal devices. */
cpu_mips_irq_init_cpu(cpu);
cpu_mips_clock_init(cpu);
/* Register 64 KB of ISA IO space at 0x1fd00000. */
memory_region_init_alias(isa, NULL, "isa_mmio",
get_system_io(), 0, 0x00010000);
memory_region_add_subregion(get_system_memory(), 0x1fd00000, isa);
/*
* A single 16450 sits at offset 0x3f8. It is attached to
* MIPS CPU INT2, which is interrupt 4.
*/
if (serial_hd(0)) {
DeviceState *dev = qdev_new(TYPE_SERIAL_MM);
qdev_prop_set_chr(dev, "chardev", serial_hd(0));
qdev_prop_set_uint8(dev, "regshift", 0);
qdev_prop_set_uint8(dev, "endianness", DEVICE_LITTLE_ENDIAN);
sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, env->irq[4]);
sysbus_add_io(SYS_BUS_DEVICE(dev), 0x3f8,
sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0));
}
if (nd_table[0].used)
/* MIPSnet uses the MIPS CPU INT0, which is interrupt 2. */
mipsnet_init(0x4200, env->irq[2], &nd_table[0]);
}
static void mips_mipssim_machine_init(MachineClass *mc)
{
mc->desc = "MIPS MIPSsim platform";
mc->init = mips_mipssim_init;
#ifdef TARGET_MIPS64
mc->default_cpu_type = MIPS_CPU_TYPE_NAME("5Kf");
#else
mc->default_cpu_type = MIPS_CPU_TYPE_NAME("24Kf");
#endif
mc->default_ram_id = "mips_mipssim.ram";
}
DEFINE_MACHINE("mipssim", mips_mipssim_machine_init)