qemu/device_tree.c
aurel32 f652e6af11 Implement device tree support needed for Bamboo emulation
To implement the -kernel, -initrd, and -append options, 4xx board emulation
must load the guest kernel as if firmware had loaded it. Where u-boot would be
the firmware, we must load the flat device tree into memory and set key fields
such as /chosen/bootargs.

This patch introduces a dependency on libfdt for flat device tree support.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6064 c046a42c-6fe2-441c-8c8c-71466251a162
2008-12-16 10:43:48 +00:00

114 lines
2.8 KiB
C

/*
* Functions to help device tree manipulation using libfdt.
* It also provides functions to read entries from device tree proc
* interface.
*
* Copyright 2008 IBM Corporation.
* Authors: Jerone Young <jyoung5@us.ibm.com>
* Hollis Blanchard <hollisb@us.ibm.com>
*
* This work is licensed under the GNU GPL license version 2 or later.
*
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include "config.h"
#include "qemu-common.h"
#include "sysemu.h"
#include "device_tree.h"
#include <libfdt.h>
void *load_device_tree(const char *filename_path, void *load_addr)
{
int dt_file_size;
int dt_file_load_size;
int new_dt_size;
int ret;
void *dt_file = NULL;
void *fdt;
dt_file_size = get_image_size(filename_path);
if (dt_file_size < 0) {
printf("Unable to get size of device tree file '%s'\n",
filename_path);
goto fail;
}
/* First allocate space in qemu for device tree */
dt_file = qemu_mallocz(dt_file_size);
if (dt_file == NULL) {
printf("Unable to allocate memory in qemu for device tree\n");
goto fail;
}
dt_file_load_size = load_image(filename_path, dt_file);
/* Second we place new copy of 2x size in guest memory
* This give us enough room for manipulation.
*/
new_dt_size = dt_file_size * 2;
fdt = load_addr;
ret = fdt_open_into(dt_file, fdt, new_dt_size);
if (ret) {
printf("Unable to copy device tree in memory\n");
goto fail;
}
/* Check sanity of device tree */
if (fdt_check_header(fdt)) {
printf ("Device tree file loaded into memory is invalid: %s\n",
filename_path);
goto fail;
}
/* free qemu memory with old device tree */
qemu_free(dt_file);
return fdt;
fail:
qemu_free(dt_file);
return NULL;
}
int qemu_devtree_setprop(void *fdt, const char *node_path,
const char *property, uint32_t *val_array, int size)
{
int offset;
offset = fdt_path_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop(fdt, offset, property, val_array, size);
}
int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
const char *property, uint32_t val)
{
int offset;
offset = fdt_path_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop_cell(fdt, offset, property, val);
}
int qemu_devtree_setprop_string(void *fdt, const char *node_path,
const char *property, const char *string)
{
int offset;
offset = fdt_path_offset(fdt, node_path);
if (offset < 0)
return offset;
return fdt_setprop_string(fdt, offset, property, string);
}