payloads/libpayload/arch/x86/rom_media.c

   1 /*
   2  *
   3  * Copyright (C) 2013 Google, Inc.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28 #define LIBPAYLOAD
  29
  30 #include <cbfs.h>
  31 #include <string.h>
  32
  33 #ifdef LIBPAYLOAD
  34 # define printk(x...)
  35 # define init_default_cbfs_media libpayload_init_default_cbfs_media
  36   extern int libpayload_init_default_cbfs_media(struct cbfs_media *media);
  37 #else
  38 # include <console/console.h>
  39 #endif
  40
  41 // Implementation of memory-mapped ROM media source on X86.
  42
  43 static int x86_rom_open(struct cbfs_media *media) {
  44         return 0;
  45 }
  46
  47 static void *x86_rom_map(struct cbfs_media *media, size_t offset, size_t count) {
  48         void *ptr;
  49         // Some address (ex, pointer to master header) may be given in memory
  50         // mapped location. To workaround that, we handle >0xf0000000 as real
  51         // memory pointer.
  52
  53         if ((uint32_t)offset > (uint32_t)0xf0000000)
  54                 ptr = (void*)offset;
  55         else
  56                 ptr = (void*)(0 - (uint32_t)media->context + offset);
  57         return ptr;
  58 }
  59
  60 static void *x86_rom_unmap(struct cbfs_media *media, const void *address) {
  61         return NULL;
  62 }
  63
  64 static size_t x86_rom_read(struct cbfs_media *media, void *dest, size_t offset,
  65                            size_t count) {
  66         void *ptr = x86_rom_map(media, offset, count);
  67         memcpy(dest, ptr, count);
  68         x86_rom_unmap(media, ptr);
  69         return count;
  70 }
  71
  72 static int x86_rom_close(struct cbfs_media *media) {
  73         return 0;
  74 }
  75
  76 int init_x86rom_cbfs_media(struct cbfs_media *media);
  77 int init_x86rom_cbfs_media(struct cbfs_media *media) {
  78         // On X86, we always keep a reference of pointer to CBFS header in
  79         // 0xfffffffc, and the pointer is still a memory-mapped address.
  80         // Since the CBFS core always use ROM offset, we need to figure out
  81         // header->romsize even before media is initialized.
  82         struct cbfs_header *header = (struct cbfs_header*)
  83                         *(uint32_t*)(0xfffffffc);
  84         if (CBFS_HEADER_MAGIC != ntohl(header->magic)) {
  85 #if CONFIG(LP_ROM_SIZE)
  86                 printk(BIOS_ERR, "Invalid CBFS master header at %p\n", header);
  87                 media->context = (void*)CONFIG_LP_ROM_SIZE;
  88 #else
  89                 return -1;
  90 #endif
  91         } else {
  92                 uint32_t romsize = ntohl(header->romsize);
  93                 media->context = (void*)romsize;
  94 #if CONFIG(LP_ROM_SIZE)
  95                 if (CONFIG_LP_ROM_SIZE != romsize)
  96                         printk(BIOS_WARNING, "rom size unmatch (%d/%d)\n",
  97                                CONFIG_LP_ROM_SIZE, romsize);
  98 #endif
  99         }
 100         media->open = x86_rom_open;
 101         media->close = x86_rom_close;
 102         media->map = x86_rom_map;
 103         media->unmap = x86_rom_unmap;
 104         media->read = x86_rom_read;
 105         return 0;
 106 }
 107
 108 int init_default_cbfs_media(struct cbfs_media *media) {
 109         return init_x86rom_cbfs_media(media);
 110 }