U-boot ddr timings file


could anyone give me a quick rundown of how to create my own ddr timings file for u-boot?

i was told in the cases where the manufacturer does not provide it, i should be able to create one on my own.

Unfortunately, this is highly SoC specific. Some vendors provide some Excel sheets to enter details about both the RAM chip(s) (usually from their datasheet(s)) and further details about the specific hardware design (e.g. swizzle and trace lengths) and generate either pseudocode (e.g. later to be pasted into SPL part of U-Boot) or further artefacts to continue the tuning workflow. Such RAM tuning may involve further tools which may be used to stress the system at various operating conditions (e.g. across the whole rated temperature range usually run inside a climate chamber) to identify and calibrate them RAM timings. To get a feel of what exactly I am talking about I may refer you to the following page from NXP about their mostly public i.MX 8M family DDR tooling: https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-8M-Family-DDR-Tool-Release/ta-p/1104467. Now, if you reveal what exact vendor and SoC you are targeting, we may find out how exactly their tooling may look like.

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what a freakin' nightmare.

so it's better (and safer) for me to expect TP-LINK to provide this sheet (that's currently missing, and resulting in the failure to compile the u-boot), right?

i'm going crazy man. this arithmetic sucks. i know it, but i don't wanna do it!

but i know daniel is expecting to have done it !!

i realised my initramfs isn't booting because for LANTIQ devices my loading address (in u-boot) isn't the same as the uimage load address. but i can't simply use a 'tftpboot <kernel load address>' and expect it to work.


BTW: What speaks against using them conf files from ax50v1_GPL/Iplatform/openwrt/package/uboot-lantiq?

good question; it's missing. see post here:

man my investigation of this platform is going to be helpful for anyone looking into it. right now it's just about figuring how to get the ramdisk detected which i hope is a noob situation. then i can worry about the u-boot flashing.

i already contacted tp-link about this missing file, which as you surmised is critical to the entire build operation.


is there any kind of generic template for these DDR files? i need to make one man.

i realised right now the 2010 u-boot probably has fk-all for EVA and this is probalby why i can't get a ramdisk boot.

i am quite sure all 3.x builds don't have EVA and this is probably the cause of everything, since enabling 'eva legacy' mode allowed the RD mount from u-boot to get detected (it was not able to do so prior)

edit: after looking, i think you're correct @sumo. there is no template. it's just a freakin' column of floating point numbers of an arbitrary length. well, it may not be arbitrary since i didn't count the rows, but it suffices to say "first inspection" supports your claim.

Sorry, but I really don't know nothing about any of this Lantiq (now actually MaxLinear, formerly Intel but likely dating back to Infineon or even Texas Instruments) stuff. It seems very hard to find any kind of public documentation about any of those chips. As stated before, usually, there would be some guidelines available from such SoC vendor about how/what exactly needs to be done. Without access to any of this it will be all just guesswork.


I'M IN. we can worry about the u-boot later. TP-LINK has assured me they're acting on my inquiry.


this is so freakin' awesome. it's a consistent boot now. oh my god this weekend is gonna be f u cking WICKED.