From ff064cd650e7690dd393c9fb0a56dd3e473eada4 Mon Sep 17 00:00:00 2001
From: Francis Rowe
- tty0_ in the coreboot IRC channel had this to say: + http://flashrom.org/ISP + is what we typically do in libreboot, though not always. That page + has some notes about using resistors to affect stability.
--<stefanct> http://flashrom.org/ISP -<stefanct> i was even using 220 ohm today -<tty0_> fchmmr: I flash with 20MHz. But had to do a lot of stuff to make it work: -<n1cky> stefanct: got a picture? -<tty0_> I made "coax" with 0.1 mm core and aluminum foley (from my kitchen), add 100 Ohm resistors (serial) -<tty0_> above the aluminum foley i've put heatshrink -<stefanct> i think that's a bit overkill :) -<tty0_> did this for: CS, CLK, D0, D1 -<tty0_> i can flash with 50MHz -* roxfan has quit (Ping timeout: 246 seconds) -<tty0_> I planned to take pics and explain -<fchmmr> sgsit, 50MHz / 0.5MHz = 100 times faster than what we are used to. -<kmalkki> and flashrom does not tell you the correct actual SPI clock -<tty0_> yep -<kmalkki> (for spidev on BBB) -<fchmmr> tty0_, I'm adding these notes to the libreboot documentation. -<tty0_> 512 takes forever (compared with this) -<fchmmr> tty0_, more notes from you (and photos), probably a full guide, would be very useful for a lot of people. -<tty0_> kmalkki: yes -<stefanct< and on the bbb the maximum is in the device tree -<tty0_> stefanct: If you have to do it many times it it worth i believe. I had so much problems flashing my x200t without it -<stefanct< in my case it is 16MHz -<stefanct< tty0_: if it helps... sure -<kmalkki> tty0_: so what hardware did you claim 50MHz with? -<tty0_> BBB - -<tty0_> http://i.imgur.com/qHGxKpj.jpg -<tty0_> BTW, i use twisted pair as core (in case i need to put capacitors) -<tty0_> One of my early x200t attempts: http://i.imgur.com/L0fVK3i.jpg - -+ +
+ tty0_ in #libreboot was able to get better flashing speeds with the following configuration: +
+