source: mainline/kernel/genarch/src/multiboot/multiboot.c@ e6b0dba

/*
 * Copyright (c) 2009 Jiri Svoboda
 * 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 <config.h>
#include <str.h>

/** Extract command name from the multiboot module command line.
 *
 * @param buf      Destination buffer (will be always NULL-terminated).
 * @param size     Size of destination buffer (in bytes).
 * @param cmd_line Input string (the command line).
 *
 */
void multiboot_extract_command(char *buf, size_t size, const char *cmd_line)
{
        /* Find the first space. */
        const char *end = str_chr(cmd_line, ' ');
        if (end == NULL)
                end = cmd_line + str_size(cmd_line);
        
        /*
         * Find last occurence of '/' before 'end'. If found, place start at
         * next character. Otherwise, place start at beginning of buffer.
         */
        const char *cp = end;
        const char *start = buf;
        
        while (cp != start) {
                if (*cp == '/') {
                        start = cp + 1;
                        break;
                }
                cp--;
        }
        
        /* Copy the command. */
        str_ncpy(buf, size, start, (size_t) (end - start));
}

/** Extract arguments from the multiboot module command line.
 *
 * @param buf      Destination buffer (will be always NULL-terminated).
 * @param size     Size of destination buffer (in bytes).
 * @param cmd_line Input string (the command line).
 *
 */
void multiboot_extract_argument(char *buf, size_t size, const char *cmd_line)
{
        /* Start after first space. */
        const char *start = str_chr(cmd_line, ' ');
        if (start == NULL) {
                str_cpy(buf, size, "");
                return;
        }

        const char *end = cmd_line + str_size(cmd_line);

        /* Skip the space(s). */
        while (start != end) {
                if (start[0] == ' ')
                        start++;
                else
                        break;
        }

        str_ncpy(buf, size, start, (size_t) (end - start));
}

static void multiboot_cmdline(char *cmdline)
{
        /*
         * GRUB passes the command line in an escaped form.
         */
        for (size_t i = 0, j = 0;
            cmdline[i] && j < CONFIG_BOOT_ARGUMENTS_BUFLEN;
            i++, j++) {
                if (cmdline[i] == '\\') {
                        switch (cmdline[i + 1]) {
                        case '\\':
                        case '\'':
                        case '\"':
                                i++;
                                break;
                        }
                }
                bargs[j] = cmdline[i];
        } 
}

static void multiboot_modules(uint32_t count, multiboot_module_t *mods)
{
        for (uint32_t i = 0; i < count; i++) {
                if (init.cnt >= CONFIG_INIT_TASKS)
                        break;
                
                init.tasks[init.cnt].paddr = mods[i].start;
                init.tasks[init.cnt].size = mods[i].end - mods[i].start;
                
                /* Copy command line, if available. */
                if (mods[i].string) {
                        multiboot_extract_command(init.tasks[init.cnt].name,
                            CONFIG_TASK_NAME_BUFLEN, MULTIBOOT_PTR(mods[i].string));
                        multiboot_extract_argument(init.tasks[init.cnt].arguments,
                            CONFIG_TASK_ARGUMENTS_BUFLEN, MULTIBOOT_PTR(mods[i].string));
                } else {
                        init.tasks[init.cnt].name[0] = 0;
                        init.tasks[init.cnt].arguments[0] = 0;
                }
                
                init.cnt++;
        }
}

static void multiboot_memmap(uint32_t length, multiboot_memmap_t *memmap)
{
        uint32_t pos = 0;
        
        while ((pos < length) && (e820counter < MEMMAP_E820_MAX_RECORDS)) {
                e820table[e820counter] = memmap->mm_info;
                
                /* Compute address of next structure. */
                uint32_t size = sizeof(memmap->size) + memmap->size;
                memmap = (multiboot_memmap_t *) ((uintptr_t) memmap + size);
                pos += size;
                
                e820counter++;
        }
}

/** Parse multiboot information structure.
 *
 * If @a signature does not contain a valid multiboot signature,
 * assumes no multiboot information is available.
 *
 * @param signature Should contain the multiboot signature.
 * @param info      Multiboot information structure.
 *
 */
void multiboot_info_parse(uint32_t signature, const multiboot_info_t *info)
{
        if (signature != MULTIBOOT_LOADER_MAGIC)
                return;

        /* Copy command line. */
        if ((info->flags & MULTIBOOT_INFO_FLAGS_CMDLINE) != 0)
                multiboot_cmdline((char *) MULTIBOOT_PTR(info->cmd_line));

        /* Copy modules information. */
        if ((info->flags & MULTIBOOT_INFO_FLAGS_MODS) != 0)
                multiboot_modules(info->mods_count,
                    (multiboot_module_t *) MULTIBOOT_PTR(info->mods_addr));
        
        /* Copy memory map. */
        if ((info->flags & MULTIBOOT_INFO_FLAGS_MMAP) != 0)
                multiboot_memmap(info->mmap_length,
                    (multiboot_memmap_t *) MULTIBOOT_PTR(info->mmap_addr));
}

/** @}
 */