Displaying 10 results from an estimated 10 matches for "sect1ptr0".
2015 Oct 20
2
Syslinux/Extlinux chain : Unexpected change of Extlinux configuration folder after reboot
...oot use the good kernel and image.
But all the following reboot (without call to extlinux -i), roll back to the previous linux image (the one used before the previous call to extlinux -i).
I'have check the boot sector content of the Ext4 partition. The pointers (found with offset computed with sect1ptr0, sect1ptr1) to the extlinux configuration change between reboot without calling extlinux.
I have backup the Ext4 partition boot sector between each reboot with this command:
dd if=/dev/sda2 of=$VERSION_DIR/boot/syslinux/bootsector.bak ibs=60928 count=1 conv=notrunc
The file comparison show an unw...
2015 Oct 20
1
Syslinux/Extlinux chain : Unexpected change of Extlinux configuration folder after reboot
...d image.
>> But all the following reboot (without call to extlinux -i), roll back to the previous linux image (the one used before the previous call to extlinux -i).
>>
>> I'have check the boot sector content of the Ext4 partition. The pointers (found with offset computed with sect1ptr0, sect1ptr1) to the extlinux configuration change between reboot without calling extlinux.
>>
>> I have backup the Ext4 partition boot sector between each reboot with this command:
>> dd if=/dev/sda2 of=$VERSION_DIR/boot/syslinux/bootsector.bak ibs=60928 count=1 conv=notrunc
>&...
2019 Apr 22
0
Installing syslinux on a purely virtual disk
...slinux.c" uses "libinstaller/syslxmod.c" to
modify the content (boot sector and ldlinux).
> The question, is there a way to simulate the work that syslinux does
> in a reasonably supportable way that won't break on future updates of
> syslinux?
>
> Rich.
>
The Sect1Ptr0_VAL and Sect1Ptr1_VAL magic values didn't change in
almost a decade. So a simple search and replace approach should work
for a while. On the other hand the required offsets are embedded in
"ldlinux.sys" (Sect1Ptr0, Sect1Ptr1 with Sect1Ptr0Ptr and Sect1Ptr1Ptr
in the extended patch are...
2015 Oct 20
0
Syslinux/Extlinux chain : Unexpected change of Extlinux configuration folder after reboot
...d kernel and image.
> But all the following reboot (without call to extlinux -i), roll back to the previous linux image (the one used before the previous call to extlinux -i).
>
> I'have check the boot sector content of the Ext4 partition. The pointers (found with offset computed with sect1ptr0, sect1ptr1) to the extlinux configuration change between reboot without calling extlinux.
>
> I have backup the Ext4 partition boot sector between each reboot with this command:
> dd if=/dev/sda2 of=$VERSION_DIR/boot/syslinux/bootsector.bak ibs=60928 count=1 conv=notrunc
> The file co...
2019 Apr 18
4
Installing syslinux on a purely virtual disk
I'm trying to add boot support to
https://github.com/libguestfs/nbdkit/tree/master/plugins/floppy
This NBD server plugin generates a completely virtual FAT filesystem
and partition table. Nothing is ever written to a file, and it must
run without anything needing to be root, loop mounting etc. Running
"syslinux --install <something>" is a non-starter.
So I've looked at
2018 Jan 05
0
Structure of VBR in FAT32?
...9;t get this part. Record?
>>
>> It's more of a list. The list has rows or records. Each record
>> indicates data about a block of the file ldlinux.sys. This data is in
>> fields for offset sector number of start and how many sectors are
>> within the block.
>Sect1Ptr0
>
> Let me see if I get this.
>
> 1. Run installer
> 2. Installer loads ldlinux.sys onto the filesystem (and copies ldlinux.c32,
> but irrelevant for now).
> 3. Installer calculates which blocks in the filesystem contain ldlinux.sys
> 4. Installer modifies first sector of ld...
2018 Jan 03
2
Structure of VBR in FAT32?
Gene, thanks for doing "Reply-All". I only get digest, so this keeps me in
the loop. Appreciated.
> which appears to be included in diskstart.inc. I will have to dig in and
> see
> > how this all gets compiled (pointers always appreciated :-) ).
>
> Yes.
>
Is the build process documented? Or am I just going to have to plod through
the makefiles?
> As Ady said,
2018 Jan 06
2
Structure of VBR in FAT32?
...ing the modified VBR back.
>
So as not to ruin the EBPB or signature, e.g.?
> > 6. Installer modifies code in VBR (a specific byte?) to indicate which
> block
> > contains first 512 bytes of ldlinux.sys
>
> It's 8 bytes for a 64-bit address located at the labels "Sect1Ptr0"
> and "Sect1Ptr1". These are NOT at fixed offsets and might move based
> on revisions of diskboot.inc.
>
That works. I will read it.
> I'd suggest against trying to make a script to install.
I have been looking at trying to leverage the installation without the...
2010 Dec 21
2
[PATCH][git-pull] core/diskstart.inc
git://git.zytor.com/users/genec/syslinux.git
Branch core-diskstart-boot-for-hpa.
I found that INT 13h AH 08h in BOCHS used ES, DI, at least when using
a partitionless HDD, causing "Boot error" from the magic check as it
was loaded to the wrong location. HPA suggested wrapping INT 13h with
the push/pop for ES's safety. This then lead to checking over for all
int 13h calls in
2018 Jan 06
0
Structure of VBR in FAT32?
...a FAT file system is near impossible to reliably read.
>> > 6. Installer modifies code in VBR (a specific byte?) to indicate which
>> > block
>> > contains first 512 bytes of ldlinux.sys
>>
>> It's 8 bytes for a 64-bit address located at the labels "Sect1Ptr0"
>> and "Sect1Ptr1". These are NOT at fixed offsets and might move based
>> on revisions of diskboot.inc.
> That works. I will read it.
>> I'd suggest against trying to make a script to install.
> I have been looking at trying to leverage the installat...