util/nvramtool/cbfs.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2008 Jordan Crouse <jordan@cosmicpenguin.net>
   5  * Copyright (C) 2011 secunet Security Networks AG
   6  *     (Written by Patrick Georgi <patrick.georgi@secunet.com>)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #ifdef __MINGW32__
  19 #include <winsock.h>
  20 #else
  21 #include <arpa/inet.h>
  22 #endif
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #ifndef __MINGW32__
  26 #include <sys/mman.h>
  27 #endif
  28 #include <stdlib.h>
  29 #include <fcntl.h>
  30 #include <string.h>
  31 #include <stdio.h>
  32 #include "cbfs.h"
  33 #include "common.h"
  34
  35 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  36 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  37
  38 static void *cbfs_mapped;
  39 static void *cbfs_offset;
  40 static void* virt_to_phys(u32 virt)
  41 {
  42         return cbfs_offset + virt;
  43 }
  44
  45 #ifdef DEBUG
  46 #define debug(x...) printf(x)
  47 #else
  48 #define debug(x...) while(0) {}
  49 #endif
  50
  51 static int cbfs_check_magic(struct cbfs_file *file)
  52 {
  53         return !strcmp(file->magic, CBFS_FILE_MAGIC) ? 1 : 0;
  54 }
  55
  56 static struct cbfs_header *cbfs_master_header(void)
  57 {
  58         struct cbfs_header *header;
  59
  60         void *ptr = virt_to_phys(*((u32*)virt_to_phys(CBFS_HEADPTR_ADDR)));
  61         debug("Check CBFS header at %p\n", ptr);
  62         header = (struct cbfs_header *) ptr;
  63
  64         debug("magic is %08x\n", ntohl(header->magic));
  65         if (ntohl(header->magic) != CBFS_HEADER_MAGIC) {
  66                 printf("ERROR: No valid CBFS header found!\n");
  67                 return NULL;
  68         }
  69
  70         debug("Found CBFS header at %p\n", ptr);
  71         return header;
  72 }
  73
  74 struct cbfs_file *cbfs_find(const char *name)
  75 {
  76         struct cbfs_header *header = cbfs_master_header();
  77         void *offset;
  78
  79         if (header == NULL)
  80                 return NULL;
  81         offset = virt_to_phys(0 - ntohl(header->romsize) + ntohl(header->offset));
  82
  83         int align= ntohl(header->align);
  84
  85         while(1) {
  86                 struct cbfs_file *file = (struct cbfs_file *) offset;
  87                 if (!cbfs_check_magic(file)) return NULL;
  88                 debug("Check %s\n", CBFS_NAME(file));
  89                 if (!strcmp(CBFS_NAME(file), name))
  90                         return file;
  91
  92                 int flen = ntohl(file->len);
  93                 int foffset = ntohl(file->offset);
  94                 debug("CBFS: follow chain: %p + %x + %x + align -> ", offset, foffset, flen);
  95
  96                 void *oldoffset = offset;
  97                 offset = (void*)ALIGN((uintptr_t)(offset + foffset + flen), align);
  98                 debug("%p\n", (void *)offset);
  99                 if (offset <= oldoffset) return NULL;
 100
 101                 if (offset < virt_to_phys(0xFFFFFFFF - ntohl(header->romsize)))
 102                         return NULL;
 103         }
 104 }
 105
 106 void *cbfs_find_file(const char *name, unsigned int type, unsigned int *len)
 107 {
 108         struct cbfs_file *file = cbfs_find(name);
 109
 110         if (file == NULL) {
 111                 printf("CBFS:  Could not find file %s\n",
 112                        name);
 113                 return NULL;
 114         }
 115
 116         if (ntohl(file->type) != type) {
 117                 printf("CBFS:  File %s is of type %x instead of"
 118                        "type %x\n", name, file->type, type);
 119
 120                 return NULL;
 121         }
 122         if (len != NULL) *len = file->len;
 123
 124         return (void *) CBFS_SUBHEADER(file);
 125 }
 126
 127 void open_cbfs(const char *filename)
 128 {
 129         struct stat cbfs_stat;
 130         int cbfs_fd;
 131
 132         cbfs_fd = open(filename, O_RDWR);
 133         if (cbfs_fd == -1) {
 134                 printf("Couldn't open '%s'\n", filename);
 135                 exit(-1);
 136         }
 137         if (fstat(cbfs_fd, &cbfs_stat) == -1) {
 138                 printf("Couldn't stat '%s'\n", filename);
 139                 exit(-1);
 140         }
 141         cbfs_mapped = mmap(NULL, cbfs_stat.st_size, PROT_READ | PROT_WRITE,
 142                         MAP_SHARED, cbfs_fd, 0);
 143         close(cbfs_fd);
 144         if (cbfs_mapped == MAP_FAILED) {
 145                 printf("Couldn't map '%s'\n", filename);
 146                 exit(-1);
 147         }
 148         cbfs_offset = cbfs_mapped-(0xffffffff-cbfs_stat.st_size+1);
 149 }