Initial file dump from open source releaseHEADmaster

1 files changed, 863 insertions, 0 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
new file mode 100644
index 00000000..26d7060c
--- /dev/null
+++ b/drivers/of/fdt.c
@@ -0,0 +1,863 @@
+/*
+ * Functions for working with the Flattened Device Tree data format
+ *
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh@kernel.crashing.org
+ *
+ * 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/kernel.h>
+#include <linux/initrd.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sizes.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
+
+#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
+#ifdef CONFIG_PPC
+#include <asm/machdep.h>
+#endif /* CONFIG_PPC */
+
+#include <asm/page.h>
+
+/**
+ * of_fdt_is_compatible - Return true if given node from the given blob has
+ * compat in its compatible list
+ * @blob: A device tree blob
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ *
+ * On match, returns a non-zero value with smaller values returned for more
+ * specific compatible values.
+ */
+int of_fdt_is_compatible(struct boot_param_header *blob,
+		      unsigned long node, const char *compat)
+{
+	const char *cp;
+	int cplen;
+	unsigned long l, score = 0;
+
+	cp = fdt_getprop(blob, node, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		score++;
+		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+			return score;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+
+/**
+ * of_fdt_match - Return true if node matches a list of compatible values
+ */
+int of_fdt_match(struct boot_param_header *blob, unsigned long node,
+                 const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_fdt_is_compatible(blob, node, *compat);
+		if (tmp && (score == 0 || (tmp < score)))
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+
+static void *unflatten_dt_alloc(void **mem, unsigned long size,
+				       unsigned long align)
+{
+	void *res;
+
+	*mem = PTR_ALIGN(*mem, align);
+	res = (void *)*mem;
+	*mem += size;
+
+	return res;
+}
+
+/**
+ * unflatten_dt_node - Alloc and populate a device_node from the flat tree
+ * @blob: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @p: pointer to node in flat tree
+ * @dad: Parent struct device_node
+ * @allnextpp: pointer to ->allnext from last allocated device_node
+ * @fpsize: Size of the node path up at the current depth.
+ */
+static void * unflatten_dt_node(struct boot_param_header *blob,
+				void *mem,
+				int *poffset,
+				struct device_node *dad,
+				struct device_node ***allnextpp,
+				unsigned long fpsize)
+{
+	const __be32 *p;
+	struct device_node *np;
+	struct property *pp, **prev_pp = NULL;
+	const char *pathp;
+	unsigned int l, allocl;
+	static int depth = 0;
+	int old_depth;
+	int offset;
+	int has_name = 0;
+	int new_format = 0;
+
+	pathp = fdt_get_name(blob, *poffset, &l);
+	if (!pathp)
+		return mem;
+
+	allocl = l++;
+
+	/* version 0x10 has a more compact unit name here instead of the full
+	 * path. we accumulate the full path size using "fpsize", we'll rebuild
+	 * it later. We detect this because the first character of the name is
+	 * not '/'.
+	 */
+	if ((*pathp) != '/') {
+		new_format = 1;
+		if (fpsize == 0) {
+			/* root node: special case. fpsize accounts for path
+			 * plus terminating zero. root node only has '/', so
+			 * fpsize should be 2, but we want to avoid the first
+			 * level nodes to have two '/' so we use fpsize 1 here
+			 */
+			fpsize = 1;
+			allocl = 2;
+			l = 1;
+			pathp = "";
+		} else {
+			/* account for '/' and path size minus terminal 0
+			 * already in 'l'
+			 */
+			fpsize += l;
+			allocl = fpsize;
+		}
+	}
+
+	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
+				__alignof__(struct device_node));
+	if (allnextpp) {
+		char *fn;
+		memset(np, 0, sizeof(*np));
+		np->full_name = fn = ((char *)np) + sizeof(*np);
+		if (new_format) {
+			/* rebuild full path for new format */
+			if (dad && dad->parent) {
+				strcpy(fn, dad->full_name);
+#ifdef DEBUG
+				if ((strlen(fn) + l + 1) != allocl) {
+					pr_debug("%s: p: %d, l: %d, a: %d\n",
+						pathp, (int)strlen(fn),
+						l, allocl);
+				}
+#endif
+				fn += strlen(fn);
+			}
+			*(fn++) = '/';
+		}
+		memcpy(fn, pathp, l);
+
+		prev_pp = &np->properties;
+		**allnextpp = np;
+		*allnextpp = &np->allnext;
+		if (dad != NULL) {
+			np->parent = dad;
+			/* we temporarily use the next field as `last_child'*/
+			if (dad->next == NULL)
+				dad->child = np;
+			else
+				dad->next->sibling = np;
+			dad->next = np;
+		}
+		kref_init(&np->kref);
+	}
+	/* process properties */
+	for (offset = fdt_first_property_offset(blob, *poffset);
+	     (offset >= 0);
+	     (offset = fdt_next_property_offset(blob, offset))) {
+		const char *pname;
+		u32 sz;
+
+		if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
+			offset = -FDT_ERR_INTERNAL;
+			break;
+		}
+
+		if (pname == NULL) {
+			pr_info("Can't find property name in list !\n");
+			break;
+		}
+		if (strcmp(pname, "name") == 0)
+			has_name = 1;
+		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
+					__alignof__(struct property));
+		if (allnextpp) {
+			/* We accept flattened tree phandles either in
+			 * ePAPR-style "phandle" properties, or the
+			 * legacy "linux,phandle" properties.  If both
+			 * appear and have different values, things
+			 * will get weird.  Don't do that. */
+			if ((strcmp(pname, "phandle") == 0) ||
+			    (strcmp(pname, "linux,phandle") == 0)) {
+				if (np->phandle == 0)
+					np->phandle = be32_to_cpup(p);
+			}
+			/* And we process the "ibm,phandle" property
+			 * used in pSeries dynamic device tree
+			 * stuff */
+			if (strcmp(pname, "ibm,phandle") == 0)
+				np->phandle = be32_to_cpup(p);
+			pp->name = (char *)pname;
+			pp->length = sz;
+			pp->value = (__be32 *)p;
+			*prev_pp = pp;
+			prev_pp = &pp->next;
+		}
+	}
+	/* with version 0x10 we may not have the name property, recreate
+	 * it here from the unit name if absent
+	 */
+	if (!has_name) {
+		const char *p1 = pathp, *ps = pathp, *pa = NULL;
+		int sz;
+
+		while (*p1) {
+			if ((*p1) == '@')
+				pa = p1;
+			if ((*p1) == '/')
+				ps = p1 + 1;
+			p1++;
+		}
+		if (pa < ps)
+			pa = p1;
+		sz = (pa - ps) + 1;
+		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
+					__alignof__(struct property));
+		if (allnextpp) {
+			pp->name = "name";
+			pp->length = sz;
+			pp->value = pp + 1;
+			*prev_pp = pp;
+			prev_pp = &pp->next;
+			memcpy(pp->value, ps, sz - 1);
+			((char *)pp->value)[sz - 1] = 0;
+			pr_debug("fixed up name for %s -> %s\n", pathp,
+				(char *)pp->value);
+		}
+	}
+	if (allnextpp) {
+		*prev_pp = NULL;
+		np->name = of_get_property(np, "name", NULL);
+		np->type = of_get_property(np, "device_type", NULL);
+
+		if (!np->name)
+			np->name = "<NULL>";
+		if (!np->type)
+			np->type = "<NULL>";
+	}
+
+	old_depth = depth;
+	*poffset = fdt_next_node(blob, *poffset, &depth);
+	if (depth < 0)
+		depth = 0;
+	while (*poffset > 0 && depth > old_depth)
+		mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp,
+					fpsize);
+
+	if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
+		pr_err("unflatten: error %d processing FDT\n", *poffset);
+
+	return mem;
+}
+
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens a device-tree, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ * @blob: The blob to expand
+ * @mynodes: The device_node tree created by the call
+ * @dt_alloc: An allocator that provides a virtual address to memory
+ * for the resulting tree
+ */
+static void __unflatten_device_tree(struct boot_param_header *blob,
+			     struct device_node **mynodes,
+			     void * (*dt_alloc)(u64 size, u64 align))
+{
+	unsigned long size;
+	int start;
+	void *mem;
+	struct device_node **allnextp = mynodes;
+
+	pr_debug(" -> unflatten_device_tree()\n");
+
+	if (!blob) {
+		pr_debug("No device tree pointer\n");
+		return;
+	}
+
+	pr_debug("Unflattening device tree:\n");
+	pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
+	pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
+	pr_debug("version: %08x\n", be32_to_cpu(blob->version));
+
+	if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
+		pr_err("Invalid device tree blob header\n");
+		return;
+	}
+
+	/* First pass, scan for size */
+	start = 0;
+	size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
+	size = ALIGN(size, 4);
+
+	pr_debug("  size is %lx, allocating...\n", size);
+
+	/* Allocate memory for the expanded device tree */
+	mem = dt_alloc(size + 4, __alignof__(struct device_node));
+
+	memset((void *)mem, 0, size);
+
+	((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
+
+	pr_debug("  unflattening %p...\n", mem);
+
+	/* Second pass, do actual unflattening */
+	start = 0;
+	unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+	if (be32_to_cpup(mem + size) != 0xdeadbeef)
+		pr_warning("End of tree marker overwritten: %08x\n",
+			   be32_to_cpu(((__be32 *)mem)[size / 4]));
+	*allnextp = NULL;
+
+	pr_debug(" <- unflatten_device_tree()\n");
+}
+
+static void *kernel_tree_alloc(u64 size, u64 align)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+/**
+ * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void of_fdt_unflatten_tree(unsigned long *blob,
+			struct device_node **mynodes)
+{
+	struct boot_param_header *device_tree =
+		(struct boot_param_header *)blob;
+	__unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
+}
+EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+
+/* Everything below here references initial_boot_params directly. */
+int __initdata dt_root_addr_cells;
+int __initdata dt_root_size_cells;
+
+struct boot_param_header *initial_boot_params;
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+/**
+ * res_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+					     const char *uname)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t base, size;
+	int len;
+	const __be32 *prop;
+	int nomap, first = 1;
+
+	prop = of_get_flat_dt_prop(node, "reg", &len);
+	if (!prop)
+		return -ENOENT;
+
+	if (len && len % t_len != 0) {
+		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+		       uname);
+		return -EINVAL;
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	while (len >= t_len) {
+		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+		size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+		if (base && size &&
+		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
+			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+		else
+			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+
+		len -= t_len;
+		if (first) {
+			fdt_reserved_mem_save_node(node, uname, base, size);
+			first = 0;
+		}
+	}
+	return 0;
+}
+
+/**
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __init __reserved_mem_check_root(unsigned long node)
+{
+	const __be32 *prop;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "ranges", NULL);
+	if (!prop)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
+					  int depth, void *data)
+{
+	static int found;
+	const char *status;
+	int err;
+
+	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
+		if (__reserved_mem_check_root(node) != 0) {
+			pr_err("Reserved memory: unsupported node format, ignoring\n");
+			/* break scan */
+			return 1;
+		}
+		found = 1;
+		/* scan next node */
+		return 0;
+	} else if (!found) {
+		/* scan next node */
+		return 0;
+	} else if (found && depth < 2) {
+		/* scanning of /reserved-memory has been finished */
+		return 1;
+	}
+
+	status = of_get_flat_dt_prop(node, "status", NULL);
+	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
+		return 0;
+
+	err = __reserved_mem_reserve_reg(node, uname);
+	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
+		fdt_reserved_mem_save_node(node, uname, 0, 0);
+
+	/* scan next node */
+	return 0;
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+	if (!initial_boot_params)
+		return;
+
+	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+	fdt_init_reserved_mem();
+}
+
+/**
+ * of_scan_flat_dt - scan flattened tree blob and call callback on each.
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree, it is
+ * used to extract the memory information at boot before we can
+ * unflatten the tree
+ */
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+				     const char *uname, int depth,
+				     void *data),
+			   void *data)
+{
+	const void *blob = initial_boot_params;
+	const char *pathp;
+	int offset, rc = 0, depth = -1;
+
+        for (offset = fdt_next_node(blob, -1, &depth);
+             offset >= 0 && depth >= 0 && !rc;
+             offset = fdt_next_node(blob, offset, &depth)) {
+
+		pathp = fdt_get_name(blob, offset, NULL);
+		if (*pathp == '/')
+			pathp = kbasename(pathp);
+		rc = it(offset, pathp, depth, data);
+	}
+	return rc;
+}
+
+/**
+ * of_get_flat_dt_root - find the root node in the flat blob
+ */
+unsigned long __init of_get_flat_dt_root(void)
+{
+	return 0;
+}
+
+/**
+ * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
+ *
+ * This function can be used within scan_flattened_dt callback to get
+ * access to properties
+ */
+const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
+				       int *size)
+{
+	return fdt_getprop(initial_boot_params, node, name, size);
+}
+
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	return of_fdt_is_compatible(initial_boot_params, node, compat);
+}
+
+/**
+ * of_flat_dt_match - Return true if node matches a list of compatible values
+ */
+int __init of_flat_dt_match(unsigned long node, const char *const *compat)
+{
+	return of_fdt_match(initial_boot_params, node, compat);
+}
+
+struct fdt_scan_status {
+	const char *name;
+	int namelen;
+	int depth;
+	int found;
+	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
+	void *data;
+};
+
+#ifdef CONFIG_BLK_DEV_INITRD
+/**
+ * early_init_dt_check_for_initrd - Decode initrd location from flat tree
+ * @node: reference to node containing initrd location ('chosen')
+ */
+void __init early_init_dt_check_for_initrd(unsigned long node)
+{
+	u64 start, end;
+	int len;
+	const __be32 *prop;
+
+	pr_debug("Looking for initrd properties... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
+	if (!prop)
+		return;
+	start = of_read_number(prop, len/4);
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
+	if (!prop)
+		return;
+	end = of_read_number(prop, len/4);
+
+	early_init_dt_setup_initrd_arch(start, end);
+	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
+		 (unsigned long long)start, (unsigned long long)end);
+}
+#else
+inline void early_init_dt_check_for_initrd(unsigned long node)
+{
+}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+/**
+ * early_init_dt_scan_root - fetch the top level address and size cells
+ */
+int __init early_init_dt_scan_root(unsigned long node, const char *uname,
+				   int depth, void *data)
+{
+	const __be32 *prop;
+
+	if (depth != 0)
+		return 0;
+
+	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (prop)
+		dt_root_size_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (prop)
+		dt_root_addr_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
+
+	/* break now */
+	return 1;
+}
+
+u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
+{
+	const __be32 *p = *cellp;
+
+	*cellp = p + s;
+	return of_read_number(p, s);
+}
+
+/**
+ * early_init_dt_scan_memory - Look for an parse memory nodes
+ */
+int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *reg, *endp;
+	int l;
+
+	/* We are scanning "memory" nodes only */
+	if (type == NULL) {
+		/*
+		 * The longtrail doesn't have a device_type on the
+		 * /memory node, so look for the node called /memory@0.
+		 */
+		if (depth != 1 || strcmp(uname, "memory@0") != 0)
+			return 0;
+	} else if (strcmp(type, "memory") != 0)
+		return 0;
+
+	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+	if (reg == NULL)
+		reg = of_get_flat_dt_prop(node, "reg", &l);
+	if (reg == NULL)
+		return 0;
+
+	endp = reg + (l / sizeof(__be32));
+
+	pr_debug("memory scan node %s, reg size %d, data: %x %x %x %x,\n",
+	    uname, l, reg[0], reg[1], reg[2], reg[3]);
+
+	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+		u64 base, size;
+
+		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
+		size = dt_mem_next_cell(dt_root_size_cells, &reg);
+
+		if (size == 0)
+			continue;
+		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
+		    (unsigned long long)size);
+
+		early_init_dt_add_memory_arch(base, size);
+	}
+
+	return 0;
+}
+
+/*
+ * Convert configs to something easy to use in C code
+ */
+#if defined(CONFIG_CMDLINE_FORCE)
+static const int overwrite_incoming_cmdline = 1;
+static const int read_dt_cmdline;
+static const int concat_cmdline;
+#elif defined(CONFIG_CMDLINE_EXTEND)
+static const int overwrite_incoming_cmdline;
+static const int read_dt_cmdline = 1;
+static const int concat_cmdline = 1;
+#else /* CMDLINE_FROM_BOOTLOADER */
+static const int overwrite_incoming_cmdline;
+static const int read_dt_cmdline = 1;
+static const int concat_cmdline;
+#endif
+
+#ifdef CONFIG_CMDLINE
+static const char *config_cmdline = CONFIG_CMDLINE;
+#else
+static const char *config_cmdline = "";
+#endif
+
+int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	int l;
+	const char *p;
+	char *cmdline = data;
+
+	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
+
+	if (depth != 1 || !cmdline ||
+	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
+		return 0;
+
+	early_init_dt_check_for_initrd(node);
+
+	/* Put CONFIG_CMDLINE in if forced or if data had nothing in it to start */
+	if (overwrite_incoming_cmdline || !cmdline[0])
+		strlcpy(cmdline, config_cmdline, COMMAND_LINE_SIZE);
+
+	/* Retrieve command line unless forcing */
+	if (read_dt_cmdline)
+		p = of_get_flat_dt_prop(node, "bootargs", &l);
+
+	if (p != NULL && l > 0) {
+		if (concat_cmdline) {
+			int cmdline_len;
+			int copy_len;
+			strlcat(cmdline, " ", COMMAND_LINE_SIZE);
+			cmdline_len = strlen(cmdline);
+			copy_len = COMMAND_LINE_SIZE - cmdline_len - 1;
+			copy_len = min((int)l, copy_len);
+			strncpy(cmdline + cmdline_len, p, copy_len);
+			cmdline[cmdline_len + copy_len] = '\0';
+		} else {
+			strlcpy(cmdline, p, min((int)l, COMMAND_LINE_SIZE));
+		}
+	}
+
+	pr_debug("Command line is: %s\n", (char*)data);
+
+	/* break now */
+	return 1;
+}
+
+#ifdef CONFIG_HAVE_MEMBLOCK
+void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	const u64 phys_offset = __pa(PAGE_OFFSET);
+	base &= PAGE_MASK;
+	size &= PAGE_MASK;
+	if (base + size < phys_offset) {
+		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
+			   base, base + size);
+		return;
+	}
+	if (base < phys_offset) {
+		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
+			   base, phys_offset);
+		size -= phys_offset - base;
+		base = phys_offset;
+	}
+	memblock_add(base, size);
+}
+
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	if (memblock_is_region_reserved(base, size))
+		return -EBUSY;
+	if (nomap)
+		return memblock_remove(base, size);
+	return memblock_reserve(base, size);
+}
+
+/*
+ * called from unflatten_device_tree() to bootstrap devicetree itself
+ * Architectures can override this definition if memblock isn't used
+ */
+void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return __va(memblock_alloc(size, align));
+}
+#else
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
+		  base, size, nomap ? " (nomap)" : "");
+	return -ENOSYS;
+}
+#endif
+
+bool __init early_init_dt_scan(void *params)
+{
+	if (!params)
+		return false;
+
+	/* Setup flat device-tree pointer */
+	initial_boot_params = params;
+
+	/* check device tree validity */
+	if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
+		initial_boot_params = NULL;
+		return false;
+	}
+
+	/* 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);
+
+	return true;
+}
+
+/**
+ * unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void __init unflatten_device_tree(void)
+{
+	__unflatten_device_tree(initial_boot_params, &of_allnodes,
+				early_init_dt_alloc_memory_arch);
+
+	/* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
+	of_alias_scan(early_init_dt_alloc_memory_arch);
+}
+
+#endif /* CONFIG_OF_EARLY_FLATTREE */