Here I'm documenting my progress on using my ac100-116 “the right way”. Feel free to reach me on irc, my nick is PaulFertser.
UPDATE 24 Oct 2016: migrated the system to current upstream U-boot and Linux. Everything seems to be nice and reliable. The limitations section still applies. Some notes on update:
rt2870.bin for stable wifinvec_event so lid open/close events are not generatedsynaptics X.org driver the elantech protocol needs to be forced for psmouse kernel drivermpv works nicely for unaccelerated video playback, including streaming from Youtube and other popular hostings (ytdl-format=18 is usually needed)U-boot doesn't support the display yet. Kernel initialises and uses the integrated panel and the backlight properly. It's possible that you'll manage this with a specially prepared bootloader that will boot from external SD automatically without a serial console.
I use a toolchain compiled by Gentoo crossdev, putusb, uboot, Marvin's 3.0.8 kernel.
Configure u-boot with make paz00_config and build it with your toolchain.
I then used my laptop and an SD card, created a single ext2 partition there and unpacked the preinstalled ubuntu rootfs. Copied the uImage to root and the created modules to /lib/modules. Erased unneeded boot scripts (including network-manager) from /etc/init/. Created there a file to start getty on ttyS0, 115200 baud. Placed a suitable wpa_supplicant.conf somewhere on the card. Removed password from /etc/shadow to give me root login.
I boot the u-boot.bin via putusb, then
mmc dev 1; ext2load mmc 1 0x408000 uImage; setenv bootargs "mem=509M@0M console=tty1 console=ttyS0,115200n8 root=/dev/mmcblk1p1"; bootm
Logged in, set password to 1, start wpa_supplicant -Dnl80211 -iwlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf &, then dhclient eth0. Installed openssh-server and switched to that (because the serial console sometimes stops to function).
Installed gdisk and repartitioned from scratch /dev/mmcblk0, creating two partitions there (one for /boot, 32M should be enough), another for LVM pv. Created LVM there, with two (for now) volumes: 1G for swap, and everything else for the rootfs. mkfs.nilfs /dev/emmc-lvm/rootfs. Mounted it, and started to Debootstrap debian armhf according to the official manual (you'll need to read both installing debian and armhf chroot, though debian-ports.org repositories are not needed).
Copied /lib/firmware/rt2870.bin to the newly established system, configured /etc/network/interfaces to bring up wlan0 for my home wlan automatically. Created a symlink from /bin/true to /usr/sbin/mkfs.nilfs2 to make the boot happy.
Initramfs is a bit tricky: a workaround from http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=649288 is needed (it has a typo where .. is used instead of . and also the script should be made +x), and also you need to pay attention to using /dev/mapper/emmc--lvm-rootfs and not /dev/emmc-lvm/rootfs for the root= kernel command line argument (see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=612402) or else initramfs won't call vgchange -ay automatically. Add nilfs2 to /etc/initramfs-tools/modules (if you're using MODULES=most). Make a symlink from initrd-3.0.8 to initramfs in /boot. You'll also need a custom initramfs-tools addon script to add nilfs_cleanerd to the initramfs or you'll need to start it later from e.g. /etc/rc.local.
The resulting system should be bootable with
mmc dev 0; ext2load mmc 0 0x408000 uImage; ext2load mmc 0 0x1408000 initramfs; setenv bootargs "mem=509M@0M console=tty1 console=ttyS0,115200n8 root=/dev/mapper/emmc--lvm-rootfs zcache initrd=0x1408000,0x${filesize}"; bootm 0x408000
You can hardcode this command line by adding
#define CONFIG_BOOTCOMMAND \
"mmc dev 0; ext2load mmc 0 0x408000 uImage; ext2load mmc 0 0x1408000 initramfs; setenv bootargs \"mem=509M@0M console=tty1 console=ttyS0,115200n8 root=/dev/mapper/emmc--lvm-rootfs zcache initrd=0x1408000,0x${filesize}\"; bootm 0x408000"
to include/configs/paz00.h and recompiling u-boot.
If you want to flash uboot as your main bootloader, get the dump of your part2 (DCT) with putusb, use bct_dump to dump the current config to file, add
BootLoader = u-boot.bin,0x00108000,0x00108000,Complete;
in there and create a new image with cbootimage. Then either flash it with putusb or from a running system by echo 0 > /sys/block/mmcblk0boot0/force_ro; dd if=newdct.bin of=/dev/mmcblk0boot0.
I managed to successfully recompile u-boot on the device itself using the Debian hardfloat native toolchain, but i needed this patch to bct_dump:
diff --git a/parse.c b/parse.c
index 1005ebc..c9153a1 100644
--- a/parse.c
+++ b/parse.c
@@ -913,7 +913,7 @@ void process_config_file(build_image_context *context)
{
char buffer[MAX_BUFFER];
int space = 0;
- char current;
+ int current;
u_int8_t c_eol_comment_start = 0; // True after first slash
u_int8_t comment = 0;
u_int8_t string = 0;
And then be sure to read suckless tips_and_tricks.