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authorjoel <joel@FreeBSD.org>2012-08-15 17:29:05 +0000
committerjoel <joel@FreeBSD.org>2012-08-15 17:29:05 +0000
commitde468fe679a47f0016408bc31c53e27bd91bae7b (patch)
tree86cb69c7ec7392a93d62a47a90a73f518dea1ab7 /share/man/man4/aout.4
parent0837e83e7ab9d4a6586490922e22a0523a1833ff (diff)
downloadFreeBSD-src-de468fe679a47f0016408bc31c53e27bd91bae7b.zip
FreeBSD-src-de468fe679a47f0016408bc31c53e27bd91bae7b.tar.gz
Minor mdoc fixes and language tweaks.
Diffstat (limited to 'share/man/man4/aout.4')
-rw-r--r--share/man/man4/aout.447
1 files changed, 24 insertions, 23 deletions
diff --git a/share/man/man4/aout.4 b/share/man/man4/aout.4
index c121fe1..57fa15e 100644
--- a/share/man/man4/aout.4
+++ b/share/man/man4/aout.4
@@ -35,16 +35,15 @@ kldload a.out
.Sh DESCRIPTION
The
.Xr a.out 5
-executable format was used by
-.Fx
-of versions \*(Lt 3.0.
-Since only i386 architecture was supported at that time, the
+executable format was used before the release of
+.Fx 3.0.
+Since i386 was the only supported architecture at that time,
.Xr a.out 5
-executables can only be activated on the platforms that support
-execution of i386 code, which are i386, amd64 and (partially) ia64.
+executables can only be activated on platforms that support
+execution of i386 code, such as i386, amd64 and (partially) ia64.
.Pp
To add kernel support for old syscalls and old syscall invocation methods,
-you need to place the following options in the kernel configuration file:
+place the following options in the kernel configuration file:
.Bd -ragged -offset indent
.Cd "options COMPAT_43"
.br
@@ -57,14 +56,16 @@ option is only required on 64-bit CPU architectures.
.Pp
The
.Va aout.ko
-module must be loaded to get support for
+module needs to be loaded with the
+.Xr kldload 8
+utility in order to support the
.Xr a.out 5
-image activator.
-Use the command
+image activator:
.Bd -ragged -offset indent
.Ic kldload aout
.Ed
-or put the following line in
+.Pp
+Alternatively, to load the module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
aout_load="YES"
@@ -72,9 +73,9 @@ aout_load="YES"
.Pp
The
.Xr a.out 5
-format was mainstream quite long time ago.
-The reasonable default settings and security requirements of the
-modern OS contradict to the default environment of that time and
+format was mainstream quite a long time ago.
+Reasonable default settings and security requirements of
+modern operating systems today contradict the default environment of that time and
require adjustments of the system to mimic natural environment for
old binaries.
.Pp
@@ -84,10 +85,10 @@ tunables are useful for this:
.Bl -tag -offset indent -width "XXXXXXXXXXXXXXXXXXXXXXXXX"
.It Xo Va security.bsd.map_at_zero
.Xc
-Set to 1 to allow the mapping of process pages at the address 0.
+Set to 1 to allow mapping of process pages at address 0.
Some very old
.Va ZMAGIC
-executable images require the text mapping at the address 0.
+executable images require text mapping at address 0.
.It Xo Va kern.pid_max
.Xc
Old versions of
@@ -96,12 +97,12 @@ used 16-bit types for
.Vt pid_t .
Current kernels use 32-bit type for
.Vt pid_t ,
-and allow the process id's up to 99999.
+and allow process id's up to 99999.
Such values cannot be represented by old
.Vt pid_t ,
-mostly causing issues for the processes using
+mostly causing issues for processes using
.Xr wait 2
-syscalls, for instance, shells.
+syscalls, for example shells.
Set the sysctl to 30000 to work around the problem.
.It Xo Va kern.elf32.read_exec
.Xc
@@ -109,7 +110,7 @@ Set to 1 to force any accessible memory mapping performed by 32-bit
process to allow execution, see
.Xr mmap 2 .
Old i386 CPUs did not have a bit in PTE which disallowed execution
-from the page, so many old programs did not specified
+from the page, so many old programs did not specify
.Va PROT_EXEC
even for mapping of executable code.
The sysctl forces
@@ -123,8 +124,6 @@ non-executable mappings.
.Xr a.out 5 ,
.Xr elf 5 ,
.Xr sysctl 8 .
-.Sh BUGS
-On 64bit architectures, not all wrappers for older syscalls are implemented.
.Sh HISTORY
The
.Xr a.out 5
@@ -132,7 +131,7 @@ executable format was used on ancient
.At
and served as the main executable format for
.Fx
-from inception up to
+from the beginning up to
.Fx 2.2.9 .
In
.Fx 3.0
@@ -143,3 +142,5 @@ The
.Nm
manual page was written by
.An Konstantin Belousov Aq kib@FreeBSD.org .
+.Sh BUGS
+On 64bit architectures, not all wrappers for older syscalls are implemented.
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