flatdevtree.c

xen 3.2.2 源码

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright Pantelis Antoniou 2006
 * Copyright IBM Corporation 2006, 2007
 * 2006 (c) MontaVista, Software, Inc.
 *
 * Authors: Pantelis Antoniou <[e-mail]>
 *          Hollis Blanchard <[e-mail]>
 *          Mark A. Greer <[e-mail]>
 */

#include "flatdevtree.h"

/* Set ptrs to current one's info; return addr of next one */
static u32 *ft_next(u32 *p, const u32 *p_strings, const u32 version,
		u32 **tagpp, char **namepp, char **datapp, u32 **sizepp)
{
	u32 sz;

	*namepp = NULL;
	*datapp = NULL;
	*sizepp = NULL;
	*tagpp = p;

	switch (be32_to_cpu(*p++)) { /* Tag */
	case OF_DT_BEGIN_NODE:
		*namepp = (char *)p;
		p = (u32 *)_ALIGN((unsigned long)p + strlen((char *)p) + 1, 4);
		break;
	case OF_DT_PROP:
		sz = be32_to_cpu(*p);
		*sizepp = p++;
		*namepp = (char *)p_strings + be32_to_cpu(*p++);
		if ((version < 0x10) && (sz >= 8))
			p = (u32 *)_ALIGN((unsigned long)p, 8);
		*datapp = (char *)p;
		p = (u32 *)_ALIGN((unsigned long)p + sz, 4);
		break;
	case OF_DT_END_NODE:
	case OF_DT_NOP:
		break;
	case OF_DT_END:
	default:
		p = NULL;
		break;
	}

	return p;
}

static void ft_put_word(struct ft_cxt *cxt, u32 v)
{
	if (cxt->overflow)	/* do nothing */
		return;

	/* check for overflow */
	if (cxt->p + 4 > cxt->pstr) {
		cxt->overflow = 1;
		return;
	}

	*(u32 *) cxt->p = cpu_to_be32(v);
	cxt->p += 4;
}

static inline void ft_put_bin(struct ft_cxt *cxt, const void *data, int sz)
{
	char *p;

	if (cxt->overflow)	/* do nothing */
		return;

	/* next pointer pos */
	p = (char *) _ALIGN((unsigned long)cxt->p + sz, 4);

	/* check for overflow */
	if (p > cxt->pstr) {
		cxt->overflow = 1;
		return;
	}

	memcpy(cxt->p, data, sz);
	if ((sz & 3) != 0)
		memset(cxt->p + sz, 0, 4 - (sz & 3));
	cxt->p = p;
}

void ft_begin_node(struct ft_cxt *cxt, const char *name)
{
	ft_put_word(cxt, OF_DT_BEGIN_NODE);
	ft_put_bin(cxt, name, strlen(name) + 1);
}

void ft_end_node(struct ft_cxt *cxt)
{
	ft_put_word(cxt, OF_DT_END_NODE);
}

void ft_nop(struct ft_cxt *cxt)
{
	ft_put_word(cxt, OF_DT_NOP);
}

static int lookup_string(struct ft_cxt *cxt, const char *name)
{
	char *p;

	p = cxt->pstr;
	while (p < cxt->pstr_begin) {
		if (strcmp(p, (char *)name) == 0)
			return p - cxt->p_begin;
		p += strlen(p) + 1;
	}

	return -1;
}

void ft_prop(struct ft_cxt *cxt, const char *name,
		const void *data, unsigned int sz)
{
	int len, off;

	if (cxt->overflow)
		return;

	len = strlen(name) + 1;

	off = lookup_string(cxt, name);
	if (off == -1) {
		/* check if we have space */
		if (cxt->p + 12 + sz + len > cxt->pstr) {
			cxt->overflow = 1;
			return;
		}

		cxt->pstr -= len;
		memcpy(cxt->pstr, name, len);
		off = cxt->pstr - cxt->p_begin;
	}

	/* now put offset from beginning of *STRUCTURE* */
	/* will be fixed up at the end */
	ft_put_word(cxt, OF_DT_PROP);
	ft_put_word(cxt, sz);
	ft_put_word(cxt, off);
	ft_put_bin(cxt, data, sz);
}

void ft_prop_str(struct ft_cxt *cxt, const char *name, const char *str)
{
	ft_prop(cxt, name, str, strlen(str) + 1);
}

void ft_prop_int(struct ft_cxt *cxt, const char *name, unsigned int val)
{
	u32 v = cpu_to_be32((u32) val);

	ft_prop(cxt, name, &v, 4);
}

/* start construction of the flat OF tree */
void ft_begin(struct ft_cxt *cxt, void *blob, unsigned int max_size)
{
	struct boot_param_header *bph = blob;
	u32 off;

	/* clear the cxt */
	memset(cxt, 0, sizeof(*cxt));

	cxt->bph = bph;
	cxt->max_size = max_size;

	/* zero everything in the header area */
	memset(bph, 0, sizeof(*bph));

	bph->magic = cpu_to_be32(OF_DT_HEADER);
	bph->version = cpu_to_be32(0x10);
	bph->last_comp_version = cpu_to_be32(0x10);

	/* start pointers */
	cxt->pres_begin = (char *) _ALIGN((unsigned long)(bph + 1), 8);
	cxt->pres = cxt->pres_begin;

	off = (unsigned long)cxt->pres_begin - (unsigned long)bph;
	bph->off_mem_rsvmap = cpu_to_be32(off);

	((u64 *) cxt->pres)[0] = 0;	/* phys = 0, size = 0, terminate */
	((u64 *) cxt->pres)[1] = 0;

	cxt->p_anchor = cxt->pres + 16;	/* over the terminator */
}

/* add a reserver physical area to the rsvmap */
void ft_add_rsvmap(struct ft_cxt *cxt, u64 physaddr, u64 size)
{
	((u64 *) cxt->pres)[0] = cpu_to_be64(physaddr);	/* phys = 0, size = 0, terminate */
	((u64 *) cxt->pres)[1] = cpu_to_be64(size);

	cxt->pres += 16;	/* advance two u64s worth */

	((u64 *) cxt->pres)[0] = 0;	/* phys = 0, size = 0, terminate */
	((u64 *) cxt->pres)[1] = 0;

	/* keep track of size */
	cxt->res_size = cxt->pres + 16 - cxt->pres_begin;

	cxt->p_anchor = cxt->pres + 16;	/* over the terminator */
}

int ft_set_rsvmap(void *bphp, int m, u64 physaddr, u64 size)
{
	const struct boot_param_header *bph = bphp;
	u64 *p_rsvmap = (u64 *)
		((char *)bph + be32_to_cpu(bph->off_mem_rsvmap));
	u32 i;

	for (i = 0;; i++) {
		u64 addr, sz;

		addr = be64_to_cpu(p_rsvmap[i * 2]);
		sz = be64_to_cpu(p_rsvmap[i * 2 + 1]);
		if (addr == 0 && size == 0)
			break;
		if (m == i) {
			p_rsvmap[i * 2] = cpu_to_be64(physaddr);
			p_rsvmap[i * 2 + 1] = cpu_to_be64(size);
			return 0;
		}
	}
	return -1;
}

void ft_begin_tree(struct ft_cxt *cxt)
{
	cxt->p_begin = cxt->p_anchor;
	cxt->pstr_begin = (char *)cxt->bph + cxt->max_size;	/* point at the end */

	cxt->p = cxt->p_begin;
	cxt->pstr = cxt->pstr_begin;
}

int ft_end_tree(struct ft_cxt *cxt)
{
	struct boot_param_header *bph = cxt->bph;
	int off, sz, sz1;
	u32 tag, v;
	char *p;

	ft_put_word(cxt, OF_DT_END);

	if (cxt->overflow)
		return -ENOMEM;

	/* size of the areas */
	cxt->struct_size = cxt->p - cxt->p_begin;
	cxt->strings_size = cxt->pstr_begin - cxt->pstr;

	/* the offset we must move */
	off = (cxt->pstr_begin - cxt->p_begin) - cxt->strings_size;

	/* the new strings start */
	cxt->pstr_begin = cxt->p_begin + cxt->struct_size;

	/* move the whole string area */
	memmove(cxt->pstr_begin, cxt->pstr, cxt->strings_size);

	/* now perform the fixup of the strings */
	p = cxt->p_begin;
	while ((tag = be32_to_cpu(*(u32 *) p)) != OF_DT_END) {
		p += 4;

		if (tag == OF_DT_BEGIN_NODE) {
			p = (char *) _ALIGN((unsigned long)p + strlen(p) + 1, 4);
			continue;
		}

		if (tag == OF_DT_END_NODE || tag == OF_DT_NOP)
			continue;

		if (tag != OF_DT_PROP)
			return -EINVAL;

		sz = be32_to_cpu(*(u32 *) p);
		p += 4;

		v = be32_to_cpu(*(u32 *) p);
		v -= off;
		*(u32 *) p = cpu_to_be32(v);	/* move down */
		p += 4;

		p = (char *) _ALIGN((unsigned long)p + sz, 4);
	}

	/* fix sizes */
	p = (char *)cxt->bph;
	sz = (cxt->pstr_begin + cxt->strings_size) - p;
	sz1 = _ALIGN(sz, 16);	/* align at 16 bytes */
	if (sz != sz1)
		memset(p + sz, 0, sz1 - sz);
	bph->totalsize = cpu_to_be32(sz1);
	bph->off_dt_struct = cpu_to_be32(cxt->p_begin - p);
	bph->off_dt_strings = cpu_to_be32(cxt->pstr_begin - p);

	/* the new strings start */
	cxt->pstr_begin = cxt->p_begin + cxt->struct_size;
	cxt->pstr = cxt->pstr_begin + cxt->strings_size;

	/* mark the size of string structure in bph */
	bph->size_dt_strings = cxt->strings_size;

	return 0;
}

/**********************************************************************/

static inline int isprint(int c)
{
	return c >= 0x20 && c <= 0x7e;
}