diff options
Diffstat (limited to 'csu/abi-note.S')
| -rw-r--r-- | csu/abi-note.S | 72 |
1 files changed, 37 insertions, 35 deletions
diff --git a/csu/abi-note.S b/csu/abi-note.S index d2051e5b3b..a5014ab5cc 100644 --- a/csu/abi-note.S +++ b/csu/abi-note.S @@ -26,44 +26,46 @@ write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -#include <sysdep.h> +/* Define an ELF note identifying the operating-system ABI that the + executable was created for. The ELF note information identifies a + particular OS or coordinated development effort within which the + ELF header's e_machine value plus (for dynamically linked programs) + the PT_INTERP dynamic linker name and DT_NEEDED shared library + names fully identify the runtime environment required by an + executable. -/* The basic layout of note sections is specified by the ELF format. */ + The general format of ELF notes is as follows. + Offsets and lengths are bytes or (parenthetical references) to the + values in other fields. -#define ELF_NOTE_BEGIN(sectname, sectflags, type, name) \ - .section sectname, sectflags; \ - .align 4; /* Notes are 4-byte aligned. */ \ - .long 1f - 0f; /* 32-bit word: length of name field */ \ - .long 3f - 2f; /* 32-bit word: length of desc field */ \ - .long (type); /* 32-bit word: vendor-defined type field */ \ -0: .asciz name; /* null-terminated string, any length: name */\ -1: .align 4; /* Name data padded to 4-byte alignment. */ \ -2: /* Here follows the "note descriptor" data, whose format \ - is not specified by ELF. The vendor name and type field \ - indicate what sort of data is found here. */ +offset length contents +0 4 length of name +4 4 length of data +8 4 note type +12 (0) vendor name + - null-terminated ASCII string, padded to 4-byte alignment +12+(0) (4) note data, -#define ELF_NOTE_END \ -3: .align 4 /* Pad to 4-byte align the next note. */ - - -/* The linker (GNU ld 2.8 and later) recognize an allocated section whose - name begins with `.note' and creates a PT_NOTE program header entry - pointing at it. - - Such a program header is the canonical way (at least in the free OS - community) to identify the OS environment ABI that the executable was - created for. The ELF note information identifies a particular OS or - coordinated development effort within which the ELF header's e_machine - value plus (for dynamically linked programs) the PT_INTERP dynamic - linker name and DT_NEEDED shared library names fully identify the - runtime environment required by an executable. - - The GNU project and cooperating development efforts (including the Linux - community) use a vendor name string of "GNU", and a note type field with - value 1 for a note descriptor that indicates ABI requirements. */ + The GNU project and cooperating development efforts (including the + Linux community) use note type 1 and a vendor name string of "GNU" + for a note descriptor that indicates ABI requirements. The note data + is four 32-bit words. The first of these is an operating system + number (0=Hurd, 1=Linux, 2=Solaris, ...) and the remaining three + identify the earliest release of that OS that supports this ABI. + See abi-tags (top level) for details. */ #include <abi-tag.h> /* OS-specific ABI tag value */ + +/* The linker (GNU ld 2.8 and later) recognizes an allocated section whose + name begins with `.note' and creates a PT_NOTE program header entry + pointing at it. */ -ELF_NOTE_BEGIN(".note.ABI-tag", "a", 1, "GNU") - .long ABI_TAG -ELF_NOTE_END + .section ".note.ABI-tag", "a" + .align 4 + .long 1f - 0f /* name length */ + .long 3f - 2f /* data length */ + .long 1 /* note type */ +0: .asciz "GNU" /* vendor name */ +1: .align 4 +2: .long ABI_TAG /* note data: the ABI tag */ +3: .align 4 /* pad out section */ |