xemu/hw/xtensa/sim.c
Peter Crosthwaite 7ef295ea5b loader: Add data swap option to load-elf
Some CPUs are of an opposite data-endianness to other components in the
system. Sometimes elfs have the data sections layed out with this CPU
data-endianness accounting for when loaded via the CPU, so byte swaps
(relative to other system components) will occur.

The leading example, is ARM's BE32 mode, which is is basically LE with
address manipulation on half-word and byte accesses to access the
hw/byte reversed address. This means that word data is invariant
across LE and BE32. This also means that instructions are still LE.
The expectation is that the elf will be loaded via the CPU in this
endianness scheme, which means the data in the elf is reversed at
compile time.

As QEMU loads via the system memory directly, rather than the CPU, we
need a mechanism to reverse elf data endianness to implement this
possibility.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-03-04 11:30:21 +00:00

117 lines
4.0 KiB
C

/*
* Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Open Source and Linux Lab nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "qemu/osdep.h"
#include "sysemu/sysemu.h"
#include "hw/boards.h"
#include "hw/loader.h"
#include "elf.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "qemu/error-report.h"
static uint64_t translate_phys_addr(void *opaque, uint64_t addr)
{
XtensaCPU *cpu = opaque;
return cpu_get_phys_page_debug(CPU(cpu), addr);
}
static void sim_reset(void *opaque)
{
XtensaCPU *cpu = opaque;
cpu_reset(CPU(cpu));
}
static void xtensa_sim_init(MachineState *machine)
{
XtensaCPU *cpu = NULL;
CPUXtensaState *env = NULL;
MemoryRegion *ram, *rom;
ram_addr_t ram_size = machine->ram_size;
const char *cpu_model = machine->cpu_model;
const char *kernel_filename = machine->kernel_filename;
int n;
if (!cpu_model) {
cpu_model = XTENSA_DEFAULT_CPU_MODEL;
}
for (n = 0; n < smp_cpus; n++) {
cpu = cpu_xtensa_init(cpu_model);
if (cpu == NULL) {
error_report("unable to find CPU definition '%s'",
cpu_model);
exit(EXIT_FAILURE);
}
env = &cpu->env;
env->sregs[PRID] = n;
qemu_register_reset(sim_reset, cpu);
/* Need MMU initialized prior to ELF loading,
* so that ELF gets loaded into virtual addresses
*/
sim_reset(cpu);
}
ram = g_malloc(sizeof(*ram));
memory_region_init_ram(ram, NULL, "xtensa.sram", ram_size, &error_fatal);
vmstate_register_ram_global(ram);
memory_region_add_subregion(get_system_memory(), 0, ram);
rom = g_malloc(sizeof(*rom));
memory_region_init_ram(rom, NULL, "xtensa.rom", 0x1000, &error_fatal);
vmstate_register_ram_global(rom);
memory_region_add_subregion(get_system_memory(), 0xfe000000, rom);
if (kernel_filename) {
uint64_t elf_entry;
uint64_t elf_lowaddr;
#ifdef TARGET_WORDS_BIGENDIAN
int success = load_elf(kernel_filename, translate_phys_addr, cpu,
&elf_entry, &elf_lowaddr, NULL, 1, EM_XTENSA, 0, 0);
#else
int success = load_elf(kernel_filename, translate_phys_addr, cpu,
&elf_entry, &elf_lowaddr, NULL, 0, EM_XTENSA, 0, 0);
#endif
if (success > 0) {
env->pc = elf_entry;
}
}
}
static void xtensa_sim_machine_init(MachineClass *mc)
{
mc->desc = "sim machine (" XTENSA_DEFAULT_CPU_MODEL ")";
mc->is_default = true;
mc->init = xtensa_sim_init;
mc->max_cpus = 4;
}
DEFINE_MACHINE("sim", xtensa_sim_machine_init)