qemu-patch-raspberry4/hw/cris/boot.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

100 lines
3.1 KiB
C

/*
* CRIS image loading.
*
* Copyright (c) 2010 Edgar E. Iglesias, Axis Communications AB.
*
* 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 "hw/hw.h"
#include "hw/loader.h"
#include "elf.h"
#include "boot.h"
static void main_cpu_reset(void *opaque)
{
CRISCPU *cpu = opaque;
CPUCRISState *env = &cpu->env;
struct cris_load_info *li;
li = env->load_info;
cpu_reset(CPU(cpu));
if (!li) {
/* nothing more to do. */
return;
}
env->pc = li->entry;
if (li->image_filename) {
env->regs[8] = 0x56902387; /* RAM boot magic. */
env->regs[9] = 0x40004000 + li->image_size;
}
if (li->cmdline) {
/* Let the kernel know we are modifying the cmdline. */
env->regs[10] = 0x87109563;
env->regs[11] = 0x40000000;
}
}
static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
{
return addr - 0x80000000LL;
}
void cris_load_image(CRISCPU *cpu, struct cris_load_info *li)
{
CPUCRISState *env = &cpu->env;
uint64_t entry, high;
int kcmdline_len;
int image_size;
env->load_info = li;
/* Boots a kernel elf binary, os/linux-2.6/vmlinux from the axis
devboard SDK. */
image_size = load_elf(li->image_filename, translate_kernel_address, NULL,
&entry, NULL, &high, 0, EM_CRIS, 0, 0);
li->entry = entry;
if (image_size < 0) {
/* Takes a kimage from the axis devboard SDK. */
image_size = load_image_targphys(li->image_filename, 0x40004000,
ram_size);
li->entry = 0x40004000;
}
if (image_size < 0) {
fprintf(stderr, "qemu: could not load kernel '%s'\n",
li->image_filename);
exit(1);
}
if (li->cmdline && (kcmdline_len = strlen(li->cmdline))) {
if (kcmdline_len > 256) {
fprintf(stderr, "Too long CRIS kernel cmdline (max 256)\n");
exit(1);
}
pstrcpy_targphys("cmdline", 0x40000000, 256, li->cmdline);
}
qemu_register_reset(main_cpu_reset, cpu);
}