efiprefix.c

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/*
 * Copyright (C) 2009 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );
FILE_SECBOOT ( PERMITTED );

#include <stdlib.h>
#include <errno.h>
#include <ipxe/device.h>
#include <ipxe/uri.h>
#include <ipxe/init.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_driver.h>
#include <ipxe/efi/efi_snp.h>
#include <ipxe/efi/efi_autoboot.h>
#include <ipxe/efi/efi_autoexec.h>
#include <ipxe/efi/efi_cachedhcp.h>
#include <ipxe/efi/efi_watchdog.h>
#include <ipxe/efi/efi_path.h>
#include <ipxe/efi/efi_veto.h>

/**
 * EFI entry point
 *
 * @v image_handle      Image handle
 * @v systab            System table
 * @ret efirc           EFI return status code
 */
EFI_STATUS EFIAPI _efi_start ( EFI_HANDLE image_handle,
                               EFI_SYSTEM_TABLE *systab ) {
        EFI_STATUS efirc;
        int rc;

        /* Initialise stack cookie */
        efi_init_stack_guard ( image_handle );

        /* Initialise EFI environment */
        if ( ( efirc = efi_init ( image_handle, systab ) ) != 0 )
                goto err_init;

        /* Claim SNP devices for use by iPXE */
        efi_snp_claim();

        /* Start watchdog holdoff timer */
        efi_watchdog_start();

        /* Call to main() */
        if ( ( rc = main() ) != 0 ) {
                efirc = EFIRC ( rc );
                goto err_main;
        }

 err_main:
        efi_watchdog_stop();
        efi_snp_release();
        efi_loaded_image->Unload ( image_handle );
        efi_driver_reconnect_all();
 err_init:
        return efirc;
}

/**
 * Initialise EFI application
 *
 */
static void efi_init_application ( void ) {
        EFI_HANDLE device = efi_loaded_image->DeviceHandle;
        EFI_DEVICE_PATH_PROTOCOL *devpath = efi_loaded_image_path;
        EFI_DEVICE_PATH_PROTOCOL *bootpath;
        struct uri *uri;

        /* Set current working URI from device path, if present */
        bootpath = efi_current_boot_path();
        DBGC ( device, "EFI has loaded image device path %s\n",
               efi_devpath_text ( devpath ) );
        DBGC ( device, "EFI has boot option device path %s\n",
               efi_devpath_text ( bootpath ) );
        uri = efi_path_uri ( devpath );
        if ( bootpath && ( ! uri ) )
                uri = efi_path_uri ( bootpath );
        if ( uri )
                churi ( uri );
        uri_put ( uri );
        free ( bootpath );

        /* Identify autoboot device, if any */
        efi_set_autoboot_ll_addr ( device, devpath );

        /* Store cached DHCP packet, if any */
        efi_cachedhcp_record ( device, devpath );
}

/** EFI application initialisation function */
struct init_fn efi_init_application_fn __init_fn ( INIT_NORMAL ) = {
        .name = "efi",
        .initialise = efi_init_application,
};

/**
 * Probe EFI root bus
 *
 * @v rootdev           EFI root device
 */
static int efi_probe ( struct root_device *rootdev __unused ) {

        /* Try loading autoexec script */
        efi_autoexec_load();

        /* Remove any vetoed drivers */
        efi_veto();

        /* Connect our drivers */
        return efi_driver_connect_all();
}

/**
 * Remove EFI root bus
 *
 * @v rootdev           EFI root device
 */
static void efi_remove ( struct root_device *rootdev __unused ) {

        /* Disconnect our drivers */
        efi_driver_disconnect_all();
}

/** EFI root device driver */
static struct root_driver efi_root_driver = {
        .probe = efi_probe,
        .remove = efi_remove,
};

/** EFI root device */
struct root_device efi_root_device __root_device = {
        .dev = { .name = "EFI" },
        .driver = &efi_root_driver,
};