| Alain Knaff | a26ee60 | 2009-01-07 00:10:27 -0800 | [diff] [blame] | 1 | /* | 
 | 2 |   initramfs_data includes the compressed binary that is the | 
 | 3 |   filesystem used for early user space. | 
 | 4 |   Note: Older versions of "as" (prior to binutils 2.11.90.0.23 | 
 | 5 |   released on 2001-07-14) dit not support .incbin. | 
 | 6 |   If you are forced to use older binutils than that then the | 
 | 7 |   following trick can be applied to create the resulting binary: | 
 | 8 |  | 
 | 9 |  | 
 | 10 |   ld -m elf_i386  --format binary --oformat elf32-i386 -r \ | 
 | 11 |   -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o | 
 | 12 |    ld -m elf_i386  -r -o built-in.o initramfs_data.o | 
 | 13 |  | 
 | 14 |   initramfs_data.scr looks like this: | 
 | 15 | SECTIONS | 
 | 16 | { | 
 | 17 |        .init.ramfs : { *(.data) } | 
 | 18 | } | 
 | 19 |  | 
 | 20 |   The above example is for i386 - the parameters vary from architectures. | 
 | 21 |   Eventually look up LDFLAGS_BLOB in an older version of the | 
 | 22 |   arch/$(ARCH)/Makefile to see the flags used before .incbin was introduced. | 
 | 23 |  | 
 | 24 |   Using .incbin has the advantage over ld that the correct flags are set | 
 | 25 |   in the ELF header, as required by certain architectures. | 
 | 26 | */ | 
 | 27 |  | 
 | 28 | .section .init.ramfs,"a" | 
 | 29 | .incbin "usr/initramfs_data.cpio.lzma" |