I know this is old,but Ill add this so that others may find it. This function seems to be present in the AMI EFI code. The leaked source code has modules that seem to handle this. The production bioses seem to have code for it as well but it could well be :"left over". In other words,it could be that they didn't implement it or disabled it,but didn't bother to remove all the pieces,or that its only enabled in debugging builds. I know Intel EFI for the developer boards contains similar functionality. The AMI seems to want the firmware to be uploaded via Xmodem. I seem to recall Xmodem was not particularly robust,but since its over a wired serial port,and the boot block presumably checks that the image is good before flashing, reliability of the protocol under a lot of errors is probably not a big deal. The nice thing about Xmodem is/was that it is simply to implement. (The issue was/is that it uses a simple check-sum on the packets it downloads. In the original xmodem implementation there are 128 bytes in a packet,or 1024 bits. Clearly there are 2^1024 possible values for the data, a vast number. There are however only 256 possible values for the check-sum. Single bit errors are easily caught by the check-sum. However, multitude errors can cause problems. You can see how its easy to get a bad packet with a good check-sum. On a relaible link it should be ok though)
Best place to start would be to boot up a pc with a terminal attached (a pc running a terminal emulator program) Of course,many modern boards do not have a serial port. Its not clear if a USB serial port will work. In fact,its not even clear if one on the PCI bus will be supported. It might have to be on the LPC buss. The LPC buss replaces the ISA buss and it is also not present on many modern motherboards. It could be the case that it requires a particular hardware configuration that is no longer there and the manufacturers dont bother to update it to the new configurations so its useless now. There is a bit of code in there with comments that discuss going through the available ports and looking for one with a terminal,so who knows. Maybe it can use different kinds of serial ports. Id still assume a USB port would not work until Id proven otherwise though.All that is assuming its built into production EFI images though.
The best best,without venturing into areas that are poorly understood,is to try the AMI recovery procedure. You hold a certain key sequence with a storage device containing a recovery image connected. A floppy used to be usable but the images are too big these days. A CDROM or USB flash drive are usually supported. A Google search or a search of your motherboard manufacturers website should find details.
This will often fix boards that dont post (if it tries to access the CD when you turn it on,its a good sign) The way this works is that there is a boot block in the flash that is only overwritten if you explicitly tell the bios flashing software to overwrite it. Ordinarily its not touched. If you have a bad flash,the boot block should still be good and you can execute the recovery procedure to fix it. Most BIOS and EFI vendors have a similar procedure (although it can be hidden on some name brand machines like Sony)
If that does not work then there is still hope. You can use a flash ROM programmer. If you have some measure of technical,and usually soldering skills,you can make one. A Google search can get you there.There is a program that someone wrote that can program SPI flash devices over a parallel port. Its made from a DB 25 connector and a few resistors and capacitors. You may or may not have to remove the flash rom from the board. If you dont have particularly great soldering skills,Id just buy a identical flash rom part off the internet and then get a tiny pair of cutters. (the little nail clippers that look like diagonal cutters are great for this) and snip the old one off the board,then clean up the pads and solder the new one on.) Find an old dead board to practice on first if you lack the experience. (A good hint is,get a good solder of the same type the board uses. In short,lead free on lead free boards,leaded on leaded boards. And get a roll of solder wick. (its a braided copper that fluxed that you use to soak up excess solder). If you find that a part has pins to close together for you to solder,you just put solder all the pins and dont worry about the "solder bridges" and then take off the excess with the solder wick. Ive had people look at me amazed and ask how I was able to solder all those tiny connections on the 80pin "postage stamp" chips with all those fine wires,or on ribbon cable connectors. Thats how you do it with simple tools.
You align the chip,and tack down one lead on the corner.. Then make sure the opposite side or corner is aligned perfectly. Then check that EVERY pin aligns. Then you tack the opposite corner down and check that everything aligns again. Then run a bead over a side. Check that everything aligns again. (If you make a mistake, you can POSSIBLY get one side all melted and reposition with a dental pick. But if you do more than one side,its very difficult to get it off again) Then wick off the excess solder and examine the pins with a magnifier. You should have perfect connections with no bridges. If you have bridges,run a new bead of solder over that side and wick it off again. Make sure THOSE pins aligned properly. Then check the other three to make sure THEY align and then solder them in place. Inspect for bridges and repeat as necessary. Make sure to use only the heat you need to avoid damaging the board or chip and let it cool between soldering. Don't hold the heat on it for more than a few seconds. (five or ten seconds is fine. Five minutes is asking for trouble)
Getting the tiny chips off is harder. On some you can CAREFULLY get some clippers in to snip the wires. But its easy to tear the pads off the board,then your screwed. (its very hard to fix,there are ways,but its allways a mess. Your best bet if it happens is to try to see where the trace goes and hope its somewhere that you can easily solder a wire. Don't try conductive ink or epoxy unless you've done it before and know some tricks to get it to work. Ive made a mess of dozens of boards trying to do that before figuring out when it will work,when it wont and how to apply it without getting it smeared everywhere.Soldering a tiny little wire is usually better. (usually just a single strand of fine stranded wire does the trick. Then,once its all working,a drop of nail polish or epoxy to stick it down in place.(let a drop dry and check it with a meter on a high ohm setting to make sure its a good insulator)
Getting a chip off intact,or even leaving a board intact is a harder proposition. Practice practice practice. on a dead worthless board. The usual trick is to run a bead of solder down one side or on a four sided chip, down two or three,then heat the sides and pry up at the corner gently with a dental pick. If you do it right the edge comes up maybe a 10th of a mm. Then repeat on the opposite side,and keep going back and forth until both sides are up about a half mm. Then wick off the solder on one side. WHen its up about a half mm or so you can get a side totally free. Then you melt the other side and quickly flip the board over and flick it off. If you do it right it comes right off and you can clean it up. If you do it wrong it tears pads off the boards. Then you hope you dont scrape off pads cleaning it. DONT EVERY RUB OR SCRAPE THE PADS WHILE HOT. (or while cold for that matter). Lay the wick down,heat,then remove while hot. if it cools you will tear the pads off. The trick is,lay the wick down, Place the iron with a clean tip on the fresh wick. The solder is wicked up. Then lift both the wick and the iron away together. If you have looked at this and though "This sounds fine,so long as your an bug eyed alien with microscopic magnifying vision with dozens of identical,each terminating in a half dozen fine manipulating appendages, you probably understand the procedure. Its a royal pain and takes a lot of skill to pull off. That does not mean you cant do it. It means if you dive in without practice,your going to make a mess of it and destroy what your trying to fix.
Think of it this way. Ive seen a lot of very nice old rifles that were "Bubbafied" Basically, repaired or refurbished by "Bubba",with a dremmel tool and a piece of sand paper. As an example, you see a wooden stock refinished and it looks horrible with sanding marks all over it and places where he sanded to far with a power sander and then the whole finish has runs and dull spots. Its terrible,and its obvious he didn't know what he was doing. Neither did I. But I got an old rifle I wanted to refinish. I started in an immediately realized I had no idea what I was doing. So I did a bunch of research. Looked at various finishing products and got a chunk of wood. And I sanded it by various means,finding out what advice from the internet was pure BS,what seemed to work and what seemed to work easily,and figured out a few things on my own. I also found that some products are total junk and some work great and that the products that promise everything in a single can are the former (For one thing they come out "gummy and soft" rather than making a hard tough protective finish) and that the old standbys and the ones that are for a single step in the multi-step "right way to do it" worked very nicely. And finally,after stripping and sanding and finishing and then stripping it all off and starting over,I had a chunk of wood,with a smooth ,resilient glossy finish on it. It took a lot of work to get there. The final process requires sanding for hours with successively finer sandpapers then finally going over it with steel wool. When you do that,you hit a point where the wood changes from that sanded look,to a glossy look where the grain comes out as you get rid of the last of scratches and make a smooth glossy finish on the wood itself. And then you apply the stain and then you do the steel wool again and then finally a hard polyurethane or epoxy finish.And the result looks like it was done by someone who really knew what they were doing.
And its not because I was magically an expert having never done it before. It was because I developed the skills to do it,before I jumped in and made a mess of it. And thats the lesson to take away. If you have to do something you have never done before,develop the skills to do it first. Practice on junk so you can get good at it before you work on stuff you care about.
Over the winter a fence blew over and put a couple of dents in my year and a half old Mustang GT. I love that car. I was very upset. Will I pay someone to fix it? No. Ive done some body work and I know its an art form. I know those dents can be taken out and you will never see them. Ive seen it done. There is a method to doing it. There are tons of videos on "panel beating" as they seem to call it in Australia and the UK.And there are tricks to avoid damaging the paint. But I cant expect to be able to do it the first time,so I will go get an old fender and my body tools and practice until I can do it right every time. Then not only will I be able to fix these dents,but any dents. I will have learned a new skill. I will have a new capability to fix things that I didn't have before.
Facebook
Twitter
Instagram