source: mainline/kernel/genarch/src/multiboot/multiboot2.c@ c3887ad

/*
 * Copyright (c) 2011 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup genarch
 * @{
 */
/** @file
 */

#include <typedefs.h>
#include <genarch/multiboot/multiboot.h>
#include <genarch/multiboot/multiboot2.h>
#include <genarch/fb/bfb.h>
#include <config.h>
#include <align.h>

#define MULTIBOOT2_TAG_ALIGN  8

static void multiboot2_module(const multiboot2_module_t *module)
{
        if (init.cnt < CONFIG_INIT_TASKS) {
                init.tasks[init.cnt].addr = PA2KA(module->start);
                init.tasks[init.cnt].size = module->end - module->start;
                multiboot_extract_command(init.tasks[init.cnt].name,
                    CONFIG_TASK_NAME_BUFLEN, module->string);
                
                init.cnt++;
        }
}

static void multiboot2_memmap(uint32_t length, const multiboot2_memmap_t *memmap)
{
        multiboot2_memmap_entry_t *entry = (multiboot2_memmap_entry_t *)
            ((uintptr_t) memmap + sizeof(*memmap));
        uint32_t pos = sizeof(*memmap);
        
        while ((pos < length) && (e820counter < MEMMAP_E820_MAX_RECORDS)) {
                e820table[e820counter].base_address = entry->base_address;
                e820table[e820counter].size = entry->size;
                e820table[e820counter].type = entry->type;
                
                /* Compute address of next entry. */
                entry = (multiboot2_memmap_entry_t *)
                    ((uintptr_t) entry + memmap->entry_size);
                pos += memmap->entry_size;
                
                e820counter++;
        }
}

static void multiboot2_fbinfo(const multiboot2_fbinfo_t *fbinfo)
{
        if (fbinfo->visual == MULTIBOOT2_VISUAL_RGB) {
                bfb_addr = fbinfo->addr;
                bfb_width = fbinfo->width;
                bfb_height = fbinfo->height;
                bfb_bpp = fbinfo->bpp;
                bfb_scanline = fbinfo->scanline;
                
                bfb_red_pos = fbinfo->rgb.red_pos;
                bfb_red_size = fbinfo->rgb.red_size;
                
                bfb_green_pos = fbinfo->rgb.green_pos;
                bfb_green_size = fbinfo->rgb.green_size;
                
                bfb_blue_pos = fbinfo->rgb.blue_pos;
                bfb_blue_size = fbinfo->rgb.blue_size;
        }
}

/** Parse multiboot2 information structure.
 *
 * If @a signature does not contain a valid multiboot2 signature,
 * assumes no multiboot2 information is available.
 *
 * @param signature Should contain the multiboot2 signature.
 * @param info      Multiboot2 information structure.
 *
 */
void multiboot2_info_parse(uint32_t signature, const multiboot2_info_t *info)
{
        if (signature != MULTIBOOT2_LOADER_MAGIC)
                return;
        
        const multiboot2_tag_t *tag = (const multiboot2_tag_t *)
            ALIGN_UP((uintptr_t) info + sizeof(*info), MULTIBOOT2_TAG_ALIGN);
        
        while (tag->type != MULTIBOOT2_TAG_TERMINATOR) {
                switch (tag->type) {
                case MULTIBOOT2_TAG_MODULE:
                        multiboot2_module(&tag->module);
                        break;
                case MULTIBOOT2_TAG_MEMMAP:
                        multiboot2_memmap(tag->size, &tag->memmap);
                        break;
                case MULTIBOOT2_TAG_FBINFO:
                        multiboot2_fbinfo(&tag->fbinfo);
                        break;
                }
                
                tag = (const multiboot2_tag_t *)
                    ALIGN_UP((uintptr_t) tag + tag->size, MULTIBOOT2_TAG_ALIGN);
        }
}

/** @}
 */