Hope someone build one USB rom emualator for openmarket.
YH
On Tue, Oct 24, 2006 at 12:30:01PM -0700, Lu, Yinghai wrote:
Hope someone build one USB rom emualator for openmarket.
What is the minimum useful size? Would 2Mbit be enough? Can anyone suggest a reasonable target price?
A USB micro, SRAM and some mux chips is really all that's needed. Maybe even use flash in the emulator. But to have an upgrade path and best configurability would probably require a PLD. (So that one hardware can do both LPC and parallell, and maybe even 3V3 but still be 5V-tolerant.)
//Peter
Peter Stuge wrote:
On Tue, Oct 24, 2006 at 12:30:01PM -0700, Lu, Yinghai wrote:
Hope someone build one USB rom emualator for openmarket.
What is the minimum useful size? Would 2Mbit be enough? Can anyone suggest a reasonable target price?
I'd say 16 Mbit, but that's just my dream of everything-in-BIOS. But IMO 4 Mbit are really the minimum.
Target price... something below 50 Euros would be nice, but I don't know whether that can be achieved.
A USB micro, SRAM and some mux chips is really all that's needed. Maybe even use flash in the emulator. But to have an upgrade path and best configurability would probably require a PLD.
What if you create something like an USB programmable BIOS saviour instead? That should fit most requirements AFACIS.
Regards, Carl-Daniel
* Carl-Daniel Hailfinger c-d.hailfinger.devel.2006@gmx.net [061025 14:02]:
Peter Stuge wrote:
On Tue, Oct 24, 2006 at 12:30:01PM -0700, Lu, Yinghai wrote:
Hope someone build one USB rom emualator for openmarket.
What is the minimum useful size? Would 2Mbit be enough? Can anyone suggest a reasonable target price?
I'd say 16 Mbit, but that's just my dream of everything-in-BIOS. But IMO 4 Mbit are really the minimum.
4 mbit really is the minimum. optimally the device would contain real flash and a microcontroller to update it in-circuit. Otherwise, it should really behave like a flash to the system, to make it usable for testing in-system flash update scenarios. (Hey, if there's no real flash in there, could the uC check the timing of the flash writes? ;-))
Target price... something below 50 Euros would be nice, but I don't know whether that can be achieved.
I am scared this might already be the price for the PLCC connector ;) the rest of the stuff could be pretty cheap though...
What if you create something like an USB programmable BIOS saviour instead? That should fit most requirements AFACIS.
I built something like that. drawback: it is slow and it requires a second machine.
Stefan
rsmith and I had been discussing that the past couple of weeks. I plan to just make one, and see how much it costs. The PLCC plug-in doohickey is always the problem, the cheapest I can find is 30USD (qty one, small discounts for more). My plan is minimum 8Mb, using a CPLD for LPC emulation and any one of the various cheap USB microcontrollers for interface. I will also add port80 decode and display for myself. I'll keep in mind the suggestions given here, they could be added later pretty easily (with more cost) What I have seen so far:
Parallel ROM emulation (with DIP pins to go with it) Parallel ROM programming LPC ROM programming NVRAM storage of the ROM data device emulation (which could be extended to making the thing into a little logic analyzer for the LPC bus)
The big hazard to this is that SPI is going to take off as the boot source soon (it is in most modern southbridges already). Talking SPI is not a problem, but the ROMs are all going to be soldered down, so running in emulator mode takes on a whole new level of pain. This project is doomed to quick obselence.
When done, I would open the design fully, so anyone could build one, or modify it to their heart's content.
Please reply to me how many of these things you would buy for $50. $75?
Thanks, Tom
On 10/24/06, Peter Stuge stuge-linuxbios@cdy.org wrote:
On Tue, Oct 24, 2006 at 12:30:01PM -0700, Lu, Yinghai wrote:
Hope someone build one USB rom emualator for openmarket.
What is the minimum useful size? Would 2Mbit be enough? Can anyone suggest a reasonable target price?
A USB micro, SRAM and some mux chips is really all that's needed. Maybe even use flash in the emulator. But to have an upgrade path and best configurability would probably require a PLD. (So that one hardware can do both LPC and parallell, and maybe even 3V3 but still be 5V-tolerant.)
//Peter
-- linuxbios mailing list linuxbios@linuxbios.org http://www.openbios.org/mailman/listinfo/linuxbios
Tom Sylla wrote:
rsmith and I had been discussing that the past couple of weeks. I plan to just make one, and see how much it costs. The PLCC plug-in doohickey is always the problem, the cheapest I can find is 30USD (qty one, small discounts for more). My plan is minimum 8Mb, using a CPLD
After some digging I found a much cheaper source. Segor electronics ( http://www.segor.de/ ) sells single PLCC32 plug-ins for 14.00 Euro (including 16% german sales tax). Quantities above 10 cost 11.20 Euro per part. If you're ordering from the US, you can get a tax refund (or maybe the tax won't even be applied in the first place). http://www.segor.de/bilder/000066d5.jpg has an image. Ordering information (where to find it in their catalogue): Hauptgruppe: Steckverbinder/Fassungen Obergruppe: Converter und Programmieradapter Warengruppe: PLCC-Stecker Artikelbezeichnung: PLCC32-Steck
The big hazard to this is that SPI is going to take off as the boot source soon (it is in most modern southbridges already). Talking SPI is not a problem, but the ROMs are all going to be soldered down, so running in emulator mode takes on a whole new level of pain. This project is doomed to quick obselence.
Wait a second. You mean socketed flash chips won't be present on future mainboards? Are there no socketed SPI chips or will the ROM storage itself be integrated into the south bridge?
When done, I would open the design fully, so anyone could build one, or modify it to their heart's content.
Please reply to me how many of these things you would buy for $50. $75?
Given that I'm a university student with limited budget, I'd appreciate a target price of $30-40. Of course this may be totally infeasible depending on how expensive the parts are.
Regards, Carl-Daniel
On 10/25/06, Carl-Daniel Hailfinger c-d.hailfinger.devel.2006@gmx.net wrote:
After some digging I found a much cheaper source. Segor electronics ( http://www.segor.de/ ) sells single PLCC32 plug-ins for 14.00 Euro (including 16% german sales tax). Quantities above 10 cost 11.20 Euro per part. If you're ordering from the US, you can get a tax refund (or maybe the tax won't even be applied in the first place).
Neat, I'll look into those.
Wait a second. You mean socketed flash chips won't be present on future mainboards? Are there no socketed SPI chips or will the ROM storage itself be integrated into the south bridge?
SPI is becoming a darling boot source, it is only 2 wires, and the ROMs are physically much smaller, but are similar densities to PLCCs. SPIs right now are mostly SO-8s, and socketing SO-8s is an expensive thing to do (much more expensive than a PLCC socket). The SPI ROMs themselves, however, are cheaper than their LPC/FWH PLCC counterparts. That is what makes me think SPI will take over soon. Maybe that is wrong, and PLCCs will last 5 more years, who knows. (NAND may also be a near term option on some southbridges)
Tom Sylla wrote:
SPI is becoming a darling boot source, it is only 2 wires, and the ROMs are physically much smaller, but are similar densities to PLCCs. SPIs right now are mostly SO-8s, and socketing SO-8s is an expensive thing to do (much more expensive than a PLCC socket). The SPI ROMs themselves, however, are cheaper than their LPC/FWH PLCC counterparts. That is what makes me think SPI will take over soon. Maybe that is wrong, and PLCCs will last 5 more years, who knows. (NAND may also be a near term option on some southbridges)
certainly in embedded soldered-on is attractive.
Our job will get harder, but I think we will have to work it out.
ron
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Carl-Daniel Hailfinger -
Lu, Yinghai -
Peter Stuge -
Ronald G Minnich -
Stefan Reinauer -
Tom Sylla