Diffstat (limited to 'doc')
2 files changed, 60 insertions, 3 deletions
diff --git a/doc/comboot.doc b/doc/comboot.doc
index c5207042..a69bfc41 100644
@@ -828,7 +828,7 @@ AX=001Ah [3.50] Cleanup, shuffle and boot to flat protected mode
AX=001Bh [3.50] Cleanup, shuffle and boot to real mode
- Input: AX 001Ah
+ Input: AX 001Bh
DX derivative-specific flags (see function 000Ch)
ES:DI shuffle descriptor list (must be in low memory)
CX number of shuffle descriptors
@@ -869,3 +869,26 @@ AX=001Bh [3.50] Cleanup, shuffle and boot to real mode
Interrupts are off and DF=0 on entry.
+AX=001Ch [3.60] Get pointer to auxilliary data vector
+ Input: AX 001Ch
+ Output: ES:BX Auxilliary data vector
+ CX Size of the ADV (currently 500 bytes)
+ The auxillary data vector is a tagged data structure used
+ to carry a small amount of information (up to 500 bytes) from
+ one boot to another.
+AX=001Dh [3.60] Write auxilliary data vector
+ Input: AX 001Dh
+ Output: None
+ Write the auxilliary data vector back to disk. Returns
+ failure for non-disk-based derivatives unless the "auxdata"
+ configuration command is used to specify a disk location
+ (not yet implemented.)
+ In a future version, PXELINUX may end up attempting to save
+ the ADV on the server via TFTP write.
diff --git a/doc/extlinux.doc b/doc/extlinux.doc
index 78f0910e..2508fa1c 100644
@@ -6,7 +6,7 @@ It works the same way as SYSLINUX, with a few slight modifications.
1. The installer is run on a *mounted* filesystem. Run the extlinux
installer on the directory in which you want extlinux installed:
- extlinux -i /boot
+ extlinux --install /boot
Specify --install (-i) to install for the first time, or
--update (-U) to upgrade a previous installation.
@@ -15,9 +15,10 @@ It works the same way as SYSLINUX, with a few slight modifications.
If /boot is a filesystem, you can do:
mkdir -p /boot/extlinux
- extlinux -i /boot/extlinux
+ extlinux --install /boot/extlinux
... to create a subdirectory and install extlinux in it.
+ /boot/extlinux is the recommended location for extlinux.
2. The configuration file is called "extlinux.conf", and is expected
@@ -42,6 +43,39 @@ It works the same way as SYSLINUX, with a few slight modifications.
+5. EXTLINUX now has "boot-once" support. The boot-once information is
+ stored in an on-disk datastructure, part of extlinux.sys, called
+ the "Auxillary Data Vector". The Auxilliary Data Vector is also
+ available to COMBOOT/COM32 modules that want to store small amounts
+ of information.
+ To set the boot-once information, do:
+ extlinux --once 'command' /boot/extlinux
+ where 'command' is any command you could enter at the SYSLINUX
+ command line. It will be executed on the next boot and then
+ To clear the boot-once information, do:
+ extlinux --clear-once /boot/extlinux
+ If EXTLINUX is used on a RAID-1, this is recommended, since under
+ certain circumstances a RAID-1 rebuild can "resurrect" the
+ boot-once information otherwise.
+ To clear the entire Auxillary Data Vector, do:
+ extlinux --reset-adv /boot/extlinux
+ This will erase all data stored in the ADV, including boot-once.
+ The --once, --clear-once, and --reset-adv commands can be combined
+ with --install or --update, if desired. The ADV is preserved
+ across updates, unless --reset-adv is specified.
Note that EXTLINUX installs in the filesystem partition like a
well-behaved bootloader :) Thus, it needs a master boot record in the
partition table; the mbr.bin shipped with SYSLINUX should work well.