cpio.h File Reference

CPIO archives. More...

#include <ipxe/image.h>

Go to the source code of this file.

Data Structures
struct	cpio_header
	A CPIO archive header. More...

Macros
#define	CPIO_MAGIC   "070701"
	CPIO magic. More...
#define	CPIO_ALIGN   4
	CPIO header length alignment. More...
#define	INITRD_ALIGN   4096
	Alignment for CPIO archives within an initrd. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static const char *	cpio_name (struct image *image)
	Get CPIO image name. More...
void	cpio_set_field (char *field, unsigned long value)
	Set field within a CPIO header. More...
size_t	cpio_name_len (struct image *image)
	Get CPIO image filename. More...
size_t	cpio_header (struct image *image, struct cpio_header *cpio)
	Construct CPIO header for image, if applicable. More...

Detailed Description

CPIO archives.

Definition in file cpio.h.

Macro Definition Documentation

CPIO_MAGIC

#define CPIO_MAGIC   "070701"

CPIO magic.

Definition at line 51 of file cpio.h.

CPIO_ALIGN

#define CPIO_ALIGN   4

CPIO header length alignment.

Definition at line 54 of file cpio.h.

INITRD_ALIGN

#define INITRD_ALIGN   4096

Alignment for CPIO archives within an initrd.

Definition at line 57 of file cpio.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

cpio_name()

static const char* cpio_name ( struct image *  image )

inlinestatic

Get CPIO image name.

Parameters

image

Image

Return values

name	Image name (not NUL terminated)

Definition at line 66 of file cpio.h.

                                  {
        return image->cmdline;
}

References image::cmdline.

Referenced by bzimage_load_initrd(), cpio_name_len(), and efi_file_read_initrd().

cpio_set_field()

void cpio_set_field	(	char *	field,
		unsigned long	value
	)

Set field within a CPIO header.

Parameters

field	Field within CPIO header
value	Value to set

Definition at line 43 of file cpio.c.

                                                         {
        char buf[9];

        snprintf ( buf, sizeof ( buf ), "%08lx", value );
        memcpy ( field, buf, 8 );
}

References memcpy(), snprintf(), and value.

Referenced by cpio_header(), and cpio_parse_cmdline().

cpio_name_len()

size_t cpio_name_len

(

struct image *

image

)

Get CPIO image filename.

Parameters

image

Image

Return values

len	CPIO filename length (0 for no filename)

Definition at line 56 of file cpio.c.

                                             {
        const char *name = cpio_name ( image );
        char *sep;
        size_t len;

        /* Check for existence of CPIO filename */
        if ( ! name )
                return 0;

        /* Locate separator (if any) */
        sep = strchr ( name, ' ' );
        len = ( sep ? ( ( size_t ) ( sep - name ) ) : strlen ( name ) );

        return len;
}

References cpio_name(), len, name, strchr(), and strlen().

Referenced by bzimage_load_initrd(), cpio_header(), and efi_file_read_initrd().

cpio_header()

size_t cpio_header	(	struct image *	image,
		struct cpio_header *	cpio
	)

Construct CPIO header for image, if applicable.

Parameters

image	Image
cpio	CPIO header to fill in

Return values

len	Length of magic CPIO header (including filename)

Definition at line 102 of file cpio.c.

                                                                     {
        size_t name_len;
        size_t len;

        /* Get filename length */
        name_len = cpio_name_len ( image );

        /* Images with no filename are assumed to already be CPIO archives */
        if ( ! name_len )
                return 0;

        /* Construct CPIO header */
        memset ( cpio, '0', sizeof ( *cpio ) );
        memcpy ( cpio->c_magic, CPIO_MAGIC, sizeof ( cpio->c_magic ) );
        cpio_set_field ( cpio->c_mode, 0100644 );
        cpio_set_field ( cpio->c_nlink, 1 );
        cpio_set_field ( cpio->c_filesize, image->len );
        cpio_set_field ( cpio->c_namesize, ( name_len + 1 /* NUL */ ) );
        cpio_parse_cmdline ( image, cpio );

        /* Calculate total length */
        len = ( ( sizeof ( *cpio ) + name_len + 1 /* NUL */ + CPIO_ALIGN - 1 )
                & ~( CPIO_ALIGN - 1 ) );

        return len;
}

References cpio_header::c_filesize, cpio_header::c_magic, cpio_header::c_mode, cpio_header::c_namesize, cpio_header::c_nlink, CPIO_ALIGN, CPIO_MAGIC, cpio_name_len(), cpio_parse_cmdline(), cpio_set_field(), len, image::len, memcpy(), and memset().

Referenced by bzimage_load_initrd(), and efi_file_read_initrd().