embedded.c

Go to the documentation of this file.

/** @file
 *
 * Embedded image support
 *
 * Embedded images are images built into the gPXE binary and do not require
 * fetching over the network.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <string.h>
#include <gpxe/image.h>
#include <gpxe/uaccess.h>
#include <gpxe/init.h>

/**
 * Free embedded image
 *
 * @v refcnt            Reference counter
 */
static void __attribute__ (( unused ))
embedded_image_free ( struct refcnt *refcnt __unused ) {
        /* Do nothing */
}

/* Raw image data for all embedded images */
#undef EMBED
#define EMBED( _index, _path, _name )                                   \
        extern char embedded_image_ ## _index ## _data[];               \
        extern char embedded_image_ ## _index ## _len[];                \
        __asm__ ( ".section \".rodata\", \"a\", @progbits\n\t"          \
                  "\nembedded_image_" #_index "_data:\n\t"              \
                  ".incbin \"" _path "\"\n\t"                           \
                  "\nembedded_image_" #_index "_end:\n\t"               \
                  ".equ embedded_image_" #_index "_len, "               \
                        "( embedded_image_" #_index "_end - "           \
                        "  embedded_image_" #_index "_data )\n\t"       \
                  ".previous\n\t" );
EMBED_ALL

/* Image structures for all embedded images */
#undef EMBED
#define EMBED( _index, _path, _name ) {                                 \
        .refcnt = { .free = embedded_image_free, },                     \
        .name = _name,                                                  \
        .data = ( userptr_t ) ( embedded_image_ ## _index ## _data ),   \
        .len = ( size_t ) embedded_image_ ## _index ## _len,            \
},
static struct image embedded_images[] = {
        EMBED_ALL
};

/**
 * Register all embedded images
 */
static void embedded_init ( void ) {
        int i;
        struct image *image;
        void *data;
        int rc;

        /* Skip if we have no embedded images */
        if ( ! sizeof ( embedded_images ) )
                return;

        /* Fix up data pointers and register images */
        for ( i = 0 ; i < ( int ) ( sizeof ( embedded_images ) /
                                    sizeof ( embedded_images[0] ) ) ; i++ ) {
                image = &embedded_images[i];

                /* virt_to_user() cannot be used in a static
                 * initialiser, so we cast the pointer to a userptr_t
                 * in the initialiser and fix it up here.  (This will
                 * actually be a no-op on most platforms.)
                 */
                data = ( ( void * ) image->data );
                image->data = virt_to_user ( data );

                DBG ( "Embedded image \"%s\": %zd bytes at %p\n",
                      image->name, image->len, data );

                if ( ( rc = register_image ( image ) ) != 0 ) {
                        DBG ( "Could not register embedded image \"%s\": "
                              "%s\n", image->name, strerror ( rc ) );
                        return;
                }
        }

        /* Load the first image */
        image = &embedded_images[0];
        if ( ( rc = image_autoload ( image ) ) != 0 ) {
                DBG ( "Could not load embedded image \"%s\": %s\n",
                      image->name, strerror ( rc ) );
                return;
        }
}

/** Embedded image initialisation function */
struct init_fn embedded_init_fn __init_fn ( INIT_NORMAL ) = {
        .initialise = embedded_init,
};