[syslinux] Sysylinux-6.03 freezes at Loading kernel..., works smooth with 4.06 via SD-CARD

[Ady]

> 
> Hi
> I have tried to install syslinux 4.06 on the SD card again, it works 
> like a charm.
> 
> I am being very carefull with c32 files from the same version 
> bootloader. No success.
> 
> I am also unmounting /dev/sdb1 before installing syslinux, as mentioned 
> in the given documentations.
> In the pasted syslinux.cfg content--- I have also tried using only one 
> DEFAULT directive. No success.
> syslinux boots successfully into SD-CARD thats for sure, as I do get 
> the boot prompt and I can even choose to load initrd0.img first, which 
> shows loading successful. But when it comes to loading the kernel, the 
> system hangs.
> 
> UEFI mode is disabled in my BIOS.
> Also I tested today the same installation procedure on a USB. Now here 
> is the interesting part, in booting from a USB with the same settings 
> and configuration. The kernel loads successfully but a new error shows 
> up resulting in a system hang.
>  ' Loading vmlinuz0 ... ok
> Loading initrd0.img... ok
> Probing EDD (edd=off to disable)... '
> The problem starts when syslinux tries to load kernel file into the 
> memory, for some reason it tries to read the wrong addresses, or maybee 
> it calculates the addresses wrongly. I have tried several paritions 
> sizes <128M  >128M ... no success.
> On your changelog, i see that you converted lots of assembly code into 
> C, somewhere there is the bug, which is not allowing for a successful 
> load of the kernel for the SD-Card case, and for the USB-case kernel is 
> loaded but again Probing EDD gets to compute the addresses wrongly.
> there is a bug in the Syslinux-6.03 code, otherwise syslinux-4.06 
> should have also shown similar issues, but it works like a charm.
> 
> Could you please point me to a documentation which allows for complete 
> compilation from scratch???
> 
> /micheal
> 

I doubt recompiling can give you a better result. Recompiling could 
also introduce potential interaction problems.

The best chance for someone to be able to replicate the problem is by 
using official pre-built binaries included in the official upstream 
archives downloaded from kernel.org, and not by rebuilding or using 
some package.

The fact that you are receiving different behaviors (instead of getting 
the same consistent error each time) might indicate that perhaps the 
problem is related to hardware or to the filesystem. Syslinux 6.03 
(final) might be only the trigger (or, as you say, it might be the 
culprit; we don't know yet).

Some possible suggestions:
0_ Check whether there is a BIOS (firmware) update available for your 
hardware.
1_ Wipe the first few MBs of your SD-Card, (warning: data will be 
erased!).
2_ Create a *new* MBR, partition table, and FAT filessytem.
3_ Use (and post here) an adequate, complete syslinux.cfg (especially 
if it works with 4.06).
4_ Use official prebuilt binaries downloaded from kernel.org.
5_ Test on another hardware combination (different mainboard / USB port 
/ USB cable / USB boot device...).
6_ Please also test in an adequate VM and report the results.

Thank you,
Ady.

PS: Not only that rebuilding Syslinux binaries is not recommended for 
troubleshooting; but additionally there have been some reports about 
building issues with nasm 2.11.06, and/or gcc 4.9.x, and/or gnu-efi 
and/or ovmf.