opengnsys_ipxe/src/include/ipxe/cpio.h

94 lines
2.1 KiB
C

#ifndef _IPXE_CPIO_H
#define _IPXE_CPIO_H
/** @file
*
* CPIO archives
*
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <ipxe/image.h>
/** A CPIO archive header
*
* All field are hexadecimal ASCII numbers padded with '0' on the
* left to the full width of the field.
*/
struct cpio_header {
/** The string "070701" or "070702" */
char c_magic[6];
/** File inode number */
char c_ino[8];
/** File mode and permissions */
char c_mode[8];
/** File uid */
char c_uid[8];
/** File gid */
char c_gid[8];
/** Number of links */
char c_nlink[8];
/** Modification time */
char c_mtime[8];
/** Size of data field */
char c_filesize[8];
/** Major part of file device number */
char c_maj[8];
/** Minor part of file device number */
char c_min[8];
/** Major part of device node reference */
char c_rmaj[8];
/** Minor part of device node reference */
char c_rmin[8];
/** Length of filename, including final NUL */
char c_namesize[8];
/** Checksum of data field if c_magic is 070702, othersize zero */
char c_chksum[8];
} __attribute__ (( packed ));
/** CPIO magic */
#define CPIO_MAGIC "070701"
/** CPIO type for regular files */
#define CPIO_MODE_FILE 0100000
/** CPIO type for directories */
#define CPIO_MODE_DIR 0040000
/** CPIO header length alignment */
#define CPIO_ALIGN 4
/** Alignment for CPIO archives within an initrd */
#define INITRD_ALIGN 4096
/**
* Get CPIO image name
*
* @v image Image
* @ret name Image name (not NUL terminated)
*/
static inline __attribute__ (( always_inline )) const char *
cpio_name ( struct image *image ) {
return image->cmdline;
}
/**
* Get CPIO header zero-padding length
*
* @v len Length of CPIO header (including name, excluding NUL)
* @ret pad_len Padding length
*/
static inline __attribute__ (( always_inline )) size_t
cpio_pad_len ( size_t len ) {
/* Pad by at least one byte (for name's terminating NUL) */
return ( CPIO_ALIGN - ( len % CPIO_ALIGN ) );
}
extern size_t cpio_header ( struct image *image, unsigned int index,
struct cpio_header *cpio );
#endif /* _IPXE_CPIO_H */