I decided to go ahead and do what I said I'd do in yesterday's entry and build a custom Linux kernel on my Kubuntu machine. I figure this will save some RAM. But first, I'd need to take up a ton of hard drive space. The packages you need just to build a kernel are slightly more than a gig and the kernel source is over 100 MB. Then I discovered at the end of the document I was using for instructions that there was a way that involved less downloading and less space. Anyway, the stock Ubuntu kernel uses 6719 KiB of memory and the vmlinuz is 4.90 MiB. When it's idle and at 50% screen brightness, it uses 21 W of power. (I read that the kernel settings could affect power usage, so that's the only reason I noted it.) After hours of downloading, configuring, and compiling, my kernel was installed. It booted, but I almost thought it froze because the screen was black and there was no hard drive activity. Then the login screen came up. This first-try kernel uses 6627 KiB of memory (about 1% less) and the vmlinuz is 4.81 MiB (90720 bytes less). After this, there were two things that didn't work properly that I have to look into: the sound card (in the regular kernel) and the video card (restricted). Even without having the right video driver, everything seems to be responsive enough; I'm not going to attempt to do anything that requires 3D acceleration. The sound card support I included was AC'97 and I realized that the audio is actually HD Audio. (I didn't think this computer was new enough. I didn't see anything about HD Audio in
lspci...) I figure once I get the audio working, I can work on getting the restricted video working correctly. Another compile later, and my audio was working. I found that I just needed to set the CONFIG_EXTRA_FIRMWARE and CONFIG_EXTRA_FIRMWARE_DIR lines to "radeon/RS690_cp.bin" and "/lib/firmware", respectively. One more compile and my kernel didn't have that 60 second delay. After this, the kernel uses 6786 KiB of memory (more than it used when I started...probably because I moved stuff I knew I needed from modules to built-ins) and the vmlinuz is 4.91 MiB (bigger again). Maybe I'll see if I can shrink it further later on. There were some drivers that I wasn't sure about, so I figure a closer look at that part would yield a leaner kernel.