Purpose
Modifies an XCOFF executable
file header.
Syntax
ldedit -b Option [ -V ] File
Description
You can use the ldedit command
to modify various fields in an XCOFF header or the auxiliary
header of an executable file. The ldedit command makes it possible
to mark or unmark an application as a 'large page data' program. The ldedit command
also makes it possible to add or modify the values of MAXDATA and
MAXSTACK without relinking.
The format of the -b flag
is similar to the format used by the link editor, the ld command.
The -b flag can be used multiple times on the command line.
If
no flags are specified, the ldedit command displays a usage
message using the standard error output.
Flags
| Item |
Description |
| -b Option |
Modifies an executable as specified by Option.
The possible values for Option are:
- datapsize:psize
- Requests psize page sizes in bytes for
data. The value can be specified as a decimal, hexadecimal, or octal
number. The number specifications are the same as in C programming
language. Additionally, the page sizes can be specified as a number
followed by a one-character suffix:
- k or K for kilo or 0x400 bytes
- m or M for mega or 0x100000 bytes
- g or G for giga or 0x40000000 bytes
- t or T for tera or 0x10000000000 bytes
- p or P for peta or 0x4000000000000 bytes
- x or X for exo or 0x1000000000000000 bytes
For example, either -b datapsize:16k or -b
datapsize:0x4000 will request 0x4000 for data and set the F_VARPG bit
in the XCOFF header. It is accomplished
by setting the corresponding member of the auxiliary header to the
logarithm base 2 of the given value psize.
If the value is different from 0, the F_VARPG bit
of the XCOFF header's f_flags member
is also set. Otherwise, this bit is cleared.
- forkpolicy:policy
- Sets the _AOUT_FORK_POLICY flag in the XCOFF auxiliary header,
if File is a 64-bit program. If policy is
cor,
the _AOUT_FORK_COW is also set, requesting the use of the copy-on-write
forktree policy. If policy is cow,
the _AOUT_FORK_COW flag is cleared, requesting the use of the copy-on-reference
forktree policy. If File is a 32-bit program,
no change is made.
- noforkpolicy
- Resets the _AOUT_FORK_POLICY and _AOUT_FORK_COR flags in the XCOFF
auxiliary header, if File is a 64-bit program.
The default forktree policy is used, unless a forktree policy is specified
with the VMM_CNTRL environment variable. If File is
a 32-bit program, no change is made.
- lpdata
- Marks a file as a 'large page data' executable.
- nolpdata
- Unmarks a file as a 'large page data' executable.
- noshrsymtab
- Clears the _AOUT_SHR_SYMTAB flag in the XCOFF auxiliary header.
If File is a 32-bit object, no change is
made.
- maxdata:value
- Sets the MAXDATA value. value is an octal number when it
starts with
0, a hexadecimal number when it starts
with 0x, and a decimal number in all other cases.
- maxdata:value/dsa
- Sets the MAXDATA value and the DSA bit. value is an octal
number when it starts with
0, a hexadecimal number
when it starts with 0x, and a decimal number in all
other cases.
|
| |
- maxstack:value
- Sets the MAXSTACK value. value is an octal number when
it starts with
0, a hexadecimal number when it starts
with 0x, and a decimal number in all other cases.
- norwexec
- Marks a file's writable and mappable sections and stack as non-executable.
- rwexec
- Marks a file's writable and mappable sections and stack as executable.
- shrsymtab
- Sets the _AOUT_SHR_SYMTAB flag in the XCOFF auxiliary header.
If File is a 64-bit program, a shared symbol
table is created when the program is run. If Flag is
a 64-bit object but not a 64-bit program, the _AOUT_SHR_SYMTAB flag
can be set, but has no effect at runtime. If File is
a 32-bit object, no change is made.
|
| |
- stackpsize:psize
- Requests psize page sizes in bytes for
process main thread stack. The value can be specified as a decimal,
hexadecimal, or octal number. The number specifications are the same
as in C programming language. Additionally, the page sizes can be
specified as a number followed by a one-character suffix:
- k or K for kilo or 0x400 bytes
- m or M for mega or 0x100000 bytes
- g or G for giga or 0x40000000 bytes
- t or T for tera or 0x10000000000 bytes
- p or P for peta or 0x4000000000000 bytes
- x or X for exo or 0x1000000000000000 bytes
For example, either -b stackpsize:16k or -b
stackpsize:0x4000 will request 0x4000 for process main thread
stack and set the F_VARPG bit in the XCOFF header.
It is accomplished by setting the corresponding member of the auxiliary
header to the logarithm base 2 of the given value psize.
If the value is different from 0, the F_VARPG bit
of the XCOFF header's f_flags member
is also set. Otherwise, this bit is cleared.
- textpsize:psize
- Requests psize page sizes in bytes for
text. The value can be specified as a decimal, hexadecimal, or octal
number. The number specifications are the same as in C programming
language. Additionally, the page sizes can be specified as a number
followed by a one-character suffix:
- k or K for kilo or 0x400 bytes
- m or M for mega or 0x100000 bytes
- g or G for giga or 0x40000000 bytes
- t or T for tera or 0x10000000000 bytes
- p or P for peta or 0x4000000000000 bytes
- x or X for exo or 0x1000000000000000 bytes
For example, either -b textpsize:16k or -b
textpsize:0x4000 will request 0x4000 for text and set the F_VARPG bit
in the XCOFF header. It is accomplished
by setting the corresponding member of the auxiliary header to the
logarithm base 2 of the given value psize.
If the value is different from 0, the F_VARPG bit
of the XCOFF header's f_flags member
is also set. Otherwise, this bit is cleared.
|
| -V |
Prints the version of the ldedit command
on the standard error output. |
Example
- To request system-selected page sizes for text, data, and stacks,
enter:
ldedit -b textpsize:0 -b datapsize:0 -b stackpsize:0
This
clears the F_VARPG bit in the XCOFF header.