svcadm(1M)을 검색하려면 섹션에서 1M 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
a.out(5)
a.out(5) File Formats a.out(5)
NAME
a.out - Executable and Linking Format (ELF) files
SYNOPSIS
#include <elf.h>
DESCRIPTION
The file name a.out is the default output file name from the link edi‐
tor, ld(1). The link editor will make an a.out executable if there were
no errors in linking. The output file of the assembler, as(1), also
follows the format of the a.out file although its default file name is
different.
Programs that manipulate ELF files may use the library that elf(3ELF)
describes. An overview of the file format follows. For more complete
information, see the references given below.
tab() box; cw(2.69i) |cw(2.81i) cw(2.69i) |cw(2.81i) Linking ViewExecu‐
tion View _ ELF headerELF header _ Program header tableProgram header
table optional _ Section 1Segment 1 _ . . . _ Section nSegment 2 _ . .
. _ . . .. . . _ Section header tableSection header table optional
An ELF header resides at the beginning and holds a "road map" describ‐
ing the file's organization. Sections hold the bulk of object file
information for the linking view: instructions, data, symbol table,
relocation information, and so on. Segments hold the object file infor‐
mation for the program execution view. As shown, a segment may contain
one or more sections.
A program header table, if present, tells the system how to create a
process image. Files used to build a process image (execute a program)
must have a program header table; relocatable files do not need one. A
section header table contains information describing the file's sec‐
tions. Every section has an entry in the table; each entry gives infor‐
mation such as the section name, the section size, etc. Files used dur‐
ing linking must have a section header table; other object files may or
may not have one.
Although the figure shows the program header table immediately after
the ELF header, and the section header table following the sections,
actual files may differ. Moreover, sections and segments have no speci‐
fied order. Only the ELF header has a fixed position in the file.
When an a.out file is loaded into memory for execution, three logical
segments are set up: the text segment, the data segment (initialized
data followed by uninitialized, the latter actually being initialized
to all 0's), and a stack. The text segment is not writable by the pro‐
gram; if other processes are executing the same a.out file, the pro‐
cesses will share a single text segment.
The data segment starts at the next maximal page boundary past the last
text address. If the system supports more than one page size, the "max‐
imal page" is the largest supported size. When the process image is
created, the part of the file holding the end of text and the beginning
of data may appear twice. The duplicated chunk of text that appears at
the beginning of data is never executed; it is duplicated so that the
operating system may bring in pieces of the file in multiples of the
actual page size without having to realign the beginning of the data
section to a page boundary. Therefore, the first data address is the
sum of the next maximal page boundary past the end of text plus the
remainder of the last text address divided by the maximal page size. If
the last text address is a multiple of the maximal page size, no dupli‐
cation is necessary. The stack is automatically extended as required.
The data segment is extended as requested by the brk(2) system call.
SEE ALSO
as(1), ld(1), brk(2), elf(3ELF)
Oracle Solaris 11.4 30 Jul 2018 a.out(5)