Sunday, November 1, 2020

Extending WiFi : DD-WRT Repeater Bridge

Base              TP-Link TL-WDR3600 v1 (link to firmware)

Extender       Cisco Linksys E4200 (link to firmware)

DD WRT version  DD-WRT v3.0-r44340 std (09/10/20)

References: https://wiki.dd-wrt.com/wiki/index.php/Repeater_Bridge

I had an earlier version working for a while and when I changed passphrase, it all fell apart. So I redid it. 

The main trouble on following the wiki instructions was that wireless and wired clients would connect to the extender, but not get an IP address. Client Brige config worked fine. So back to the repeater bridge. I added an AP to the extender on the second wifi band and it works fine now. I realize this is not recommended by the wiki. 

So use at your own caution. I'd still suggest following the wiki instructions above. If all else fails, try adding an AP .


Adding NVME boot support to Asrock Z68 Pro3

 This is possible and it worked for me. However, use at your own risk: Flashing BIOS is risky.

  The main idea is from this post.

Notes:

  1. Original BIOS version was 2.30  . This had padded sections so I couldn't use UEFITool. MMtool worked fine to insert NVME support. 
  2. Older BIOSes had no space to insert even compressed version of NVME support
  3. This worked for me on an Intel drive
  4. NvmExpressDxe_4.ffs was not sufficient to add boot support.
  5. I extracted the 3 NVME support files from Asrock Z97 Pro3 and inserted them into 2.30 instead of NvmExpressDxe_4.ffs . This worked and both Windows and Linux can boot from NVME. 

As an initial caution, I disconnected all other drives from the motherboard. UEFI defaults. I'll add other components one by one. 


Tuesday, April 21, 2020

Older laptops, linux, usability

Yes this is from April 2020

Exhibit 1
IBM Thinkpad A21m
Pentium III 750Mhz
512 MB RAM
ATI rage mobility
1024x768 display

Exhibit 2
Dell Inspiron 8500
Mobile Pentium 4 2.6 Ghz/1.2Ghz 
512 MB RAM
nvidia geforce4 4200
1920x1200 display

The surprise (to someone who started linux by juggling slackware floppies and CDs) is that all recent distros I tried at least came up to X. But they were generally slow because of lack of hardware rendering. Wifi was not always straightforward with b43 support.

Previously installed older distros (Debian 3.1, 5) on (1) laptop was not very usable - SSL . Windows XP after more than a decade of accumulation was very slow.

After many trials (included kernel recompiles which took overnight) with Debian 10, Ubuntu 18.04 LTS, Mint, Antix, Arch, and other distros, I converged on just doing what was done before - follow previous directions. Maybe I'll yet try to backport learnings to a newer distro.

Exhibit (2) turned out to be easier to get going than Exhibit (1) .

wifi with b43 turned out to be easier than hardware rendering

(2) Mint 13 with nvidia drivers
Tux racer works great

3.2.0-23-generic
xorg-server 2:1.11.4-0ubuntu10.17

(1) Ubuntu 8.04 "Hardy Heron" with compiled mach64.ko and drm.ko
Tux racer not great. But good usability otherwise.
Firefox / SSL problem still exists. I dug out CDRW because this won't start from USB directly. And 2/4  discs didn't boot completely.

The linksys wifi card (WPC600N) only seemed to work well with ndiswrapper.

References:
http://www.bakarasse.de/pages/en/linux/3d-with-ati-mach64/ubuntu-hardy.php?lang=EN
    precompiled .ko were hard to download
    Using source from here, I was able to compile the modules. They sometimes loaded when using startx or X -config from console, but hard hang when starting X from boot.

https://bugs.freedesktop.org/show_bug.cgi?id=21945

    I used ab582f64fd54565f66eba866972f0fe2c313f000 from https://gitlab.freedesktop.org/mesa/drm.git
    This worked for me.

    I tried changing IRQs from 11 to see if that had a dependence (Bios-config-PCI). It mostly made things worse.

    Adding agp_mode 2, made things go haywire.

2.6.24-32-386
X.Org X Server 1.4.0.90

Write to me if you want to look at xorg.conf or /var/log/Xorg.0.log