arm-netbook March 2017

arm-netbook@lists.phcomp.co.uk

39 participants
27 discussions

rk3288 ddr ram initialisation reverse-engineering.... a ray of hope!
by Luke Kenneth Casson Leighton 16 Mar '17

16 Mar '17

yay i believe i may have _finally_ tracked down the issue with the DDR3 RAM initialisation - not the actual underlying problem with the PCB layout (which is down to impedance and is probably going to need insertion of a bank of... probably like... 60-80 resistors... *sigh*...) but with initialising the RK3288 RAM controller at the much lower clock rate of 200mhz. i _really_ should have checked the rkclk_configure_ddr function in u-boot-rockchip's clk_rk3288.c file first, but i have to say it's been great fun doing reverse-engineering again. i basically took the rkbin/rk32/ 32_LPDDR2_200MHz_LPDDR3_200MHz_DDR3_200MHz_20150318.bin file which rockchip supplied - and which is confirmed as successfully initialising the DDR3 controller (at 200mhz) on the EOMA68-RK3288 board - and have been rapidly working it back towards c-code. ... probably unnecessarily as it turns out, because *actually* what i quite likely only needed was to add "200mhz" as one of the supported switch-statements in rkclk_configure_ddr! ooops.... now, it has to be said that if i had not got as far through the reverse-engineering as i have, i would not have had the information that i needed in order to easily work out the PLL settings for the 200mhz clock-rate. the reason is quite straightforward: the proprietary binary is SIGNIFICANTLY more comprehensive in its initialisation, parameterisation, safety-checking and follow-up testing of the memory. i can see _where_ the u-boot-rockchip sdram initialisation comes from: many of the functions are the same but the key strategic ones are significantly improved. so, anyway, it's late evening, so i cannot go round to my host's house straight away and test this out, but i will do tomorrow first thing :) l. --- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

1 0

AMD considering releasing the PSP
by Julie Marchant 15 Mar '17

15 Mar '17

Trisquel forum thread here: https://trisquel.info/en/forum/amd-apparently-taking-requests-feedback-comm… And this is the Reddit thread where it happened: https://www.reddit.com/r/Amd/comments/5x4hxu/we_are_amd_creators_of_athlon_… It would be a good idea to encourage AMD to do this. Who knows? It could lead us to an x86 EOMA computer card of some sort in the future. ;) Not to mention, it would just be better for us overall to have AMD on our side. -- Julie Marchant https://onpon4.github.io Protect your emails with GnuPG: https://emailselfdefense.fsf.org

9 32

AMD considering releasing the PSP
by Mike Leimon 15 Mar '17

15 Mar '17

> Ok so basically this will allow type II cards( smaller) to fit into type > III housings and utilize higher clocks ? I think the idea is a bit better than that even. I think that by default all Type II cards must adhere/support the 5W upper thermal limit. However, even in a Type II slot the card may negotiate with a housing and if the housing can support heat removal from the card to allow it to operate at a higher (10W?) limit, then the card may then utilize a faster clock rate or activate more cores (at that point). > Also from my understanding the > type III card will be the physical form factor used for the EOMA 200 > standard ? No, I think this is a misunderstanding. I'm pretty sure that the EOMA-200 standard will have 202 pins Please see the following page for details: http://elinux.org/Embedded_Open_Modular_Architecture/EOMA-200

2 1

Prototype Circuit Board Printer
by Mike Leimon 15 Mar '17

15 Mar '17

Just in case you all haven't seen this before (or haven't thought about it). I was thinking that since it seems like lots of prototype boards are being made perhaps a prototype circuit board printer like the following might be useful for prototyping some of the simpler support boards (e.g. some of the laptop PCBs). https://voltera.io/ I'm not exactly sure how much cheaper (if any) that it would be compared to getting prototype boards printed up by another company but, I could imagine that being able to print up your own circuit boards would probably help speed up the design/prototype iteration cycle. -Mike

2 1

Funding
by mike.valk＠gmail.com 15 Mar '17

15 Mar '17

Interesting read: https://medium.com/open-collective/why-and-how-to-fund-the-open-source-proj…

1 0

EOMA68 booting process
by Luke Kenneth Casson Leighton 14 Mar '17

14 Mar '17

On Thu, Mar 9, 2017 at 3:46 PM, mike.valk(a)gmail.com <mike.valk(a)gmail.com> wrote: thanks for the explanation, mike. > So for EOMA we must set/invent a standard which Installers can use > regardless the SoC type used in the EOMA card. ah. right. the way i see it, the only thing that needs to happen is that the card has to have enough on-board storage to get to u-boot (or similar) where it can then recognise the EOMA68 I2C EEPROM (and get the ID info) or for it to (pretty much) always boot externally and do the same. anything beyond tthat needs to be analysed *really* carefully, right through its impllications down the *entire* lifecycle. which is why i currently have it as (pretty much) "card must self-boot and must adapt to EOMA68 EEPROM ID" and it's left as generically as that > On A20 et.al. there is the FEL mode. Which is initialized by that first > loaded program. from ROM. > In this FEL mode you can push an image over USB-OTG. But > that requires an active USB host not just an USB thumb drive. i do this all the time. i don't develop for the A20 in any other way. when i see the shit that people get themselves into *even though usb-fel was written years ago* by trying to un-fuck their systems using LIVESHIT.EXE and other crap i'm just... staggered and genuinely confused. it's *real* simple and needs just *seven* lines of bash script: fel write 0x2000 ./fel-boot-spl-EOMA68_A20_2GB.bin sleep 1 fel exe 0x2000 sleep 1 fel write 0x4a000000 u-boot.new.bin sleep 1 fel exe 0x4a000000 the fel-boot-spl.bin is actually the u-boot-spl.bin executable that's compiled by default in u-boot if you select "CONFIG_SPL". the u-boot.new.bin is u-boot without the spl part tacked onto the front. it really couldn't be simpler. you can if you want directly upload the linux kernel, script.bin, dtb file, initramdisk WHATEVER YOU LIKE directly into memory and then execute it DIRECTLY. you don't even need u-boot to do it. > http://linux-sunxi.org/FEL/USBBoot#Booting_U-Boot_over_USB > http://linux-sunxi.org/BROM > > So the question is are "we" going to build such a thing? i'm yet to be convinced that it's necessary, beyond adapting u-boot and the linux kernel to read and adapt to the ID in the EOMA68 EEPROM. what specifically did you have in mind? l. > >> >> >> -- hendrik >> >> >> _______________________________________________ >> arm-netbook mailing list arm-netbook(a)lists.phcomp.co.uk >> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook >> Send large attachments to arm-netbook(a)files.phcomp.co.uk > > > > _______________________________________________ > arm-netbook mailing list arm-netbook(a)lists.phcomp.co.uk > http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook > Send large attachments to arm-netbook(a)files.phcomp.co.uk

2 4

article about.... netbooks
by Luke Kenneth Casson Leighton 14 Mar '17

14 Mar '17

and they're even running arm processors. this *being* a mailing list *named* "arm-netbooks" (duh) it's my responsibility and duty to make people aware of e.g. this :) https://mobile.slashdot.org/story/17/03/12/2140230/can-crowdfunding-bring-b… l.

1 0

laptop 15in PCB4 "stand-alone power board"
by Luke Kenneth Casson Leighton 13 Mar '17

13 Mar '17

hi, in order to work towards getting the laptop out in phases i'm looking to create an intermediary design that utilises the exact same PCB1 from the laptop, exact same LCD, without the STM32F board (PCB2) and without the battery charger board (PCB3)... which in effect makes an "LCD monitor" when utilised with a passthrough Card or an "all-in-one PC" when utilised with a card that has a processor in it. a review of the (simple) schematics for PCB4 would be really useful, although they are in fact very very simple. please note though that i will be delaying prototyping PCB4 and PCB1 until the latest micro-desktop revision (1.7) has been prototyped and confirmed working with its SD/MMC level-shifting. i missed that bit... so do not wish to waste backer funds by potentially making a mistake on the micro-desktop 1.7 PCB that's *duplicated* on laptop PCB1. http://hands.com/~lkcl/eoma/laptop_15in/pcb4 --- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

2 2

eoma68 rk3288 testing
by Luke Kenneth Casson Leighton 12 Mar '17

12 Mar '17

http://rhombus-tech.net/rock_chips/rk3288/news/ i now have 2 assembled PCBs with the exact same "fault" - which after talking to paulk and akaka on #linux-rockchip i *may* have a lead on how to get the DDR3 RAM up and running properly. we believe it's down to the impedance control register (ZQCR) which is being hard-coded in u-boot-rockchip rather than being allowed to "train". those values are suited for 6-layer 1.6mm PCBs - the impedance of tracks when you have an 8-layer 1.2mm PCB are *half* what they are for 6-layer 1.6mm PCBs. l. --- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

2 8

Libre CNC milling toolchain
by Lars Kruse 11 Mar '17

11 Mar '17

Hi Luke, I just read your last update [1], even though it is already three weeks old. It was a good and interesting read - thank you for that! There you mentioned the bad shape of Free Software in the fields of CNC milling. In general I have to agree. But I think, it is not as bleak as you experienced it. There is indeed a usable toolchain of Free Software for 2D or 3D design, toolpath generation and machine control. Sadly especially the toolpath generation process is far from being as fast and full of features as it should be. Personally I maintain PyCAM [2] (a toolpath generator). The toolpath generators are the weak link between a range of good libre 3D and 2D design software and linuxcnc [3] - an excellent and mature software for machine control. Feel free to contact me, if this topic is of any practical interest for you right now. Cheers, Lars [1] https://www.crowdsupply.com/eoma68/micro-desktop/updates/progress-physics-t… [2] http://pycam.sf.net/ [3] http://linuxcnc.org/

3 3

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

arm-netbook March 2017