Snap 4100 Bios Questions
 

Ok, like many before me I am going to venture on solving the 137GB barrier. I got one of these units a few days ago and this problem doesn't seem insurmountable.

I have some rudimentary questions that if anyone knows the answer to it would speed up this process.

1: Does anyone know where the bios is physically stored. I only found an Intel 28F016S5-120 chip which is a "Flash FileSystem" chip. I *think* that the bios is stored in a small portion of this.
2: Where can I get a copy of a bios upgrade. *Any* version would do for me.
3: Does anyone know if the bios is a proprietary one, or perhaps a stripped down award/phoenix bios?

Cheers

Re: Snap 4100 Bios Questions
 

Ok, how about just throwing a hint where I can find a bios upgrade file to download?

If I have a copy of a bios file, then i can find out where in memory it is stored more easily.

Gord

Re: Snap 4100 Bios Questions
 

You need to read the FAQ's.

These units do not support LBA48Bit addressing. Max usable capacity is 130gig.

Re: Snap 4100 Bios Questions
 

*Sigh*

I have read the FAQ. I have found the OS update.

I am requesting information on the BIOS, and if updates were made/issued and if they were released.

I am a programmer with the knowledge and experience to tackle this...

Screw it. I'll do it myself.

Re: Snap 4100 Bios Questions
 

This problem has been addressed before. The BIOS and OS are in the same flashram. There is no specific BIOS on the 4100. The problem is the Original snaps used 24 bit addressing. There was a problem with the 4100 controller chip, it had a bug that did not work in 48 bit. Adaptec at the time decided it was not worth the effort to fix the problem due to flashram restraints.

There are several old threads aimed at the code uploaded to the flashram. The code is in HEX loaded to a specific address.

Re: Snap 4100 Bios Questions
 

Thank you! That was very useful.

Basically, from what I've found is that the flash image that you see is actually a full OS file system of sorts. I've been working on fiddling with the loading of the OS to insert the correct routines. It was actually found that the chip itself wasn't faultly, just the driver.

However, thank you for your post, I will keep working, and if anyone has anything useful to add, I would appreciate. (Thats useful to add. Please, refrain from the "it can't be done, its been tried, etc etc" stuff.)

Cheers

Re: Snap 4100 Bios Questions
 

The original controller chips did have a bug but was caught and replaced before other models were impacted. Instead of just locking out the ones impacted they elected to kill it on all 4100's. So current models will work if the apporate code can be uploaded.

The code is loaded by IBM HEX which specifies a address for the hex code to load into. Without the source code you will have a large task ahead of you.

The os is broken down by platformbytes. This is imbeded into the snaps ID/BIOS. When the os is loaded it looks at the platformbytes then it has instructions for what parts are needed.

This info should get you started. It's been over 4yrs since I looked at it.

Good luck.

Re: Snap 4100 Bios Questions
 

Thanks! I appreciate that information. This advances me miles from where I was going. My plan at this point is to pull the flash chip, read it, and compare the contents to a known bin file.

One thought I had was to just say screw it with the existing OS, and see if I can figure out a way of reconstructing the appropriate file system on the chip and make a version of freenas work. Although, my thoughts are that the chip may not be big enough, but, if the BIOS can boot into a section of flash ram, perhaps I could install a boot loader there, and then point it towards a partition on a drive?

Not sure where i"m heading but this is my thought process so far.

Thanks *alot*

Re: Snap 4100 Bios Questions
 

I kid of started that direction till I found 1 of the 2 flashram chips were soldered in. Requires a TSOP48 base to read the chips...

I was thinking it would be easier to have the bios std so it would revert to the HD's instead of memory location.

Re: Snap 4100 Bios Questions
 

I'm going to be pulling the chip fairly soon. Life took over for a bit. If it doesn't contravene any laws or ethics or something, I will post a copy of the raw contents of the flash when I've got it off.

I looked at the data sheet and it doesn't have a boot block like many of the flash chips I'm used to dealing with. So, I'm presuming it picks some arbitratry spot to load and execute.

If I can find that point then we're cruisin' to happy town.

I had another thought. I wonder if these units share a bios with other units that do support 48bit. If they do, perhaps they check some value stored in an eeprom during post and disable things accordingly, and its a matter of disabling those routines?

Another thought that runs through my head is with the size of the eeprom being limited, perhaps the best route would be is to find the location of the "boot block" that it loads and executes after post and just stuff Grub on there. I'd imagine its all gravy after that point.

Rambling over :hammer:

Cheers