Qi is a boot manager. It is designed to replace uBoot. But Qi will be simpler and faster.
Qi's concept is it leaves everything possible to Linux, that includes even the video init. Therefore Qi does NOT provide a boot menu. The usual NOR uBoot menu you use to flash your Neo (Aux first, power second, wait for menu) of course works fine, but if you try the usual procedure to fire up NAND uBoot (Power first, aux second, wait for menu) you get no response. (not even the 'backlighted black screen')
Qi will boot from any kernel named uImage-GTA0[123...].bin in the /boot folder in the root of an ext2 or ext3 partition on the uSD card.
- Qi looks for a kernel in the first, second and third partition, silently ignoring FAT partitions.
- Qi expects the / (root) filesystem to be on the same partition as /boot.
- If both uImage-GTA02 and uImage-GTA03 files are present, Qi loads the right one for the machine.
Failing to find a kernel in the SD card, Qi will boot from the kernel in NAND (if the kernel works of course, see below). Failing to find a valid kernel, Qi perform a memory test. It means that one can either move kernels out of the way to get the memory test, or make an SD Card just with normal Qi on it and no kernels to get a memory test.
- Up to Nov. 28th, Qi would blink the blue Power LED a fraction of a second every 10 secs or so to say nothing valid to boot.
Download and installation
The daily download is a qi-s3cXXXX-andy_somenumber.udfu file at http://people.openmoko.org/andy/ . (look at your dmesg output for the CPU to pick the right s3c* version.)
The installation should be flashing like;
# dfu-util -a u-boot -R -D qi-s3c6410-andy_8589b40295653557.udfu
Enabling console messages
on the rootfs in question, put in there
and you'll see the messages on boot. If it's NAND right now you need to edit the default commandline in Qi for gta02.
Testing speed improvements
Stopwatch results on Qi (error is approx ±1/2 second):
Booting SHR image with uBoot:
- 0:00 power button held down
- 0:07 splash screen appears
- 0:15 drops to console showing kernel messages scrolling by for ~1 minute
- 1:18 Openmoko 'please wait' splash
- 1:31 desktop animated splash
- 2:38 finished booting
Booting identical setup with Qi flashed over uBoot:
- 0:00 power button held down
- 0:06 backlit black
- 0:13 please wait booting... (only this text on console for next 38 seconds)
- 0:51 Angstrom console message (at the end of kernel output with uBoot, but ONLY text display to appear throughout this stage with Qi)
- 0:54 Openmoko 'please wait' splash
- 1:05 desktop animated splash
- 1:54 finished booting
So for this particular configuration, it reduced time-to-desktop by about 28%, about 44 seconds. Surprisingly, the later segments of booting (desktop) were also noticeably faster than with uBoot - One would have expected just the fist stages up until init (kernel finished establishing itself) to be faster.
- Qi won't boot the 'first try' after power restored - the tester didn't count that first 10 seconds for Qi to be fair to its booting speed, not penalize it for what appears to be a bug that bears no relation to actual boot speed).
- The current (Oct. 12, 2008) 2.6.27 kernel does not boot from the build-in flash NAND. It only works from the uSD boot on ext3. If one tries to boot it from the flash, then AUX red LED blinks ~4/sec. This means kernel panic... It's panicking because it has no rootfs because it can't mount the jffs2 because of the CRC errors because there is a bug that the mtd are not done properly.
- Qi often doesn't want to resume after suspend.
- Qi is able to load kernels larger than 2MB correctly, uBoot has a bug.
- Without "console=tty0 loglevel=8" in append-GTA02, and especially the loglevel variable, Qi fails to boot the SD, claiming it has an unknown root device (2,0).
LED codes summary
- One Blue shine every ~10 second: did not found any valid kernel to boot
- About four RED shines per second: kernel panic.