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/*
* Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
*
* Based on reduced version of METAG
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/reboot.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <asm/prom.h>
#include <asm/clk.h>
#include <asm/mach_desc.h>
/**
* setup_machine_fdt - Machine setup when an dtb was passed to the kernel
* @dt: virtual address pointer to dt blob
*
* If a dtb was passed to the kernel, then use it to choose the correct
* machine_desc and to setup the system.
*/
struct machine_desc * __init setup_machine_fdt(void *dt)
{
struct boot_param_header *devtree = dt;
struct machine_desc *mdesc = NULL, *mdesc_best = NULL;
unsigned int score, mdesc_score = ~1;
unsigned long dt_root;
const char *model, *compat;
void *clk;
char manufacturer[16];
unsigned long len;
/* check device tree validity */
if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
return NULL;
initial_boot_params = devtree;
dt_root = of_get_flat_dt_root();
/*
* The kernel could be multi-platform enabled, thus could have many
* "baked-in" machine descriptors. Search thru all for the best
* "compatible" string match.
*/
for_each_machine_desc(mdesc) {
score = of_flat_dt_match(dt_root, mdesc->dt_compat);
if (score > 0 && score < mdesc_score) {
mdesc_best = mdesc;
mdesc_score = score;
}
}
if (!mdesc_best) {
const char *prop;
long size;
pr_err("\n unrecognized device tree list:\n[ ");
prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
if (prop) {
while (size > 0) {
printk("'%s' ", prop);
size -= strlen(prop) + 1;
prop += strlen(prop) + 1;
}
}
printk("]\n\n");
machine_halt();
}
/* compat = "<manufacturer>,<model>" */
compat = mdesc_best->dt_compat[0];
model = strchr(compat, ',');
if (model)
model++;
strlcpy(manufacturer, compat, model ? model - compat : strlen(compat));
pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer);
/* Retrieve various information from the /chosen node */
of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
/* Initialize {size,address}-cells info */
of_scan_flat_dt(early_init_dt_scan_root, NULL);
/* Setup memory, calling early_init_dt_add_memory_arch */
of_scan_flat_dt(early_init_dt_scan_memory, NULL);
clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len);
if (clk)
arc_set_core_freq(of_read_ulong(clk, len/4));
return mdesc_best;
}
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