UART pins and serial line parameters

[onegulin]

The second picture is very informative, thanks for it.
What is the uart pin assignment? What are the serial line parameters?
Thanks.

[MyPod-zz]

115200. You'll just need GND, RX, TX.

[ChrisThePL]

Is this UART to iDrac console ? Can I revovery iDrac image by TFTP like iDrac6 ?

[MyPod-zz]

This is UART to J_IDRAC_UART. To recover via TFTP you need access to the u-boot console, which Dell has locked down and further restriced access to in 2.61.60.60.

[hh010]

I find 4pin BMC_UART on the mainboard, maybe it can use TTL write the image to U_EMMC, And the other 4pin is FVS_HEADER.

[Fohdeesha]

there are easy to use recovery commands to re-program EMMC flash from within u-boot, but you have to get there first. There is some special sequences/methods to get it to drop to a u-boot shell over the UART, I will probably publish them soon

[hh010]

can you share the 4m bin of the IDRAC_SPI？

[Fohdeesha]

I haven't verified this dump, but I think it's valid. from my R720

http://fohdeesha.com/data/other/R720-SPI.bin

[WenceyWang]

there are easy to use recovery commands to re-program EMMC flash from within u-boot, but you have to get there first. There is some special sequences/methods to get it to drop to a u-boot shell over the UART, I will probably publish them soon

Is there any document to get into the u-boot shell?

[TrendMend]

Any updates to this?

[dudududodododedede]

see this post for how to interrupt uboot:

https://www.win-raid.com/t3828f16-Problem-Dell-R-xd-iDRAC-BIOS-Recovery-4.html#msg73352

[dudududodododedede]

note that if you have idrac 2.61.60.60 or newer then this method doesn't work anymore (dell patched it)

[Fohdeesha]

@dudududodododedede the SW_IDRAC_DBG jumper u-boot entry was patched out? About time, I'm surprised they left it active as long as they did. As for the method we used for the exploit in this repo, it involved shorting specific EMMC flash pins in a certain way so that u-boot could not read its boot storage, so would instead drop down into the u-boot shell. I believe dell patched this around the same version once we reported it to them

[hafizfurqan]

For future references pics for CP210X USB to UART pinout for PowerEdge R720

[hafizfurqan]

For future references pics for CP210X USB to UART pinout

A more cleaner pic with interrupt pins

[adiee5]

note that if you have idrac 2.61.60.60 or newer then this method doesn't work anymore (dell patched it)

so, how can i interrupt uboot if i have a newer version? (mine's either 2.65.15.65.65 or 2.65.65.65.10, both versions are displayed in the terminal)