source: bootcd/isolinux/syslinux-6.03/com32/gpllib/acpi/rsdp.c

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2009-2011 Erwan Velu - All Rights Reserved
 *
 *   Permission is hereby granted, free of charge, to any person
 *   obtaining a copy of this software and associated documentation
 *   files (the "Software"), to deal in the Software without
 *   restriction, including without limitation the rights to use,
 *   copy, modify, merge, publish, distribute, sublicense, and/or
 *   sell copies of the Software, and to permit persons to whom
 *   the Software is furnished to do so, subject to the following
 *   conditions:
 *
 *   The above copyright notice and this permission notice shall
 *   be included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 *
 * -----------------------------------------------------------------------
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <dprintf.h>
#include "acpi/acpi.h"

int search_rsdp(s_acpi * acpi)
{
    /* Let's seach for RSDT table */
    uint8_t *q;

    /* Let's start for the base address */
    for (q = (uint8_t *)RSDP_MIN_ADDRESS; q < (uint8_t *)RSDP_MAX_ADDRESS; q+=16 ) {
        /* Searching for RSDP with "RSD PTR" signature */
        if (memcmp(q, RSDP, sizeof(RSDP)-1) == 0) {
            s_rsdp *r = &acpi->rsdp;
            r->valid = true;
            r->address = q;
            cp_str_struct(r->signature);
            cp_struct(&r->checksum);
            cp_str_struct(r->oem_id);
            cp_struct(&r->revision);
            cp_struct(&r->rsdt_address);
            cp_struct(&r->length);
            cp_struct(&r->xsdt_address);
            cp_struct(&r->extended_checksum);
            q += 3;             /* reserved field */
            acpi->rsdt.address = r->rsdt_address;
            acpi->xsdt.address = r->xsdt_address;
            DEBUG_PRINT(("RSDT should be at %p\n",r->rsdt_address));
            DEBUG_PRINT(("XSDT should be at %p\n",r->xsdt_address));
            return RSDP_TABLE_FOUND;
        }
    }
    return -RSDP_TABLE_FOUND;
}

void print_rsdp(s_acpi * acpi)
{
    s_rsdp *r = &acpi->rsdp;

    if (!r->valid)
        return;
    printf("RSDP Table @ 0x%p\n", r->address);
    printf(" signature         : %s\n", r->signature);
    printf(" checksum          : %u\n", r->checksum);
    printf(" oem id            : %s\n", r->oem_id);
    printf(" revision          : %u\n", r->revision);
    printf(" RDST address      : %p\n", r->rsdt_address);
    printf(" length            : %u\n", r->length);
    printf(" XSDT address      : %p\n", r->xsdt_address);
    printf(" extended checksum : %u\n", r->extended_checksum);
}