====== Debian hardfloat with upstream U-Boot ======
Here I'm documenting my progress on using my ac100-116 "the right way". Feel free to reach me on [[help#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:
* Needs the latest (from firmware git) ''rt2870.bin'' for stable wifi
* Missing ''nvec_event'' so lid open/close events are not generated
* To be able to use ''synaptics'' X.org driver the ''elantech'' protocol needs to be forced for ''psmouse'' kernel driver
* ''mpv'' works nicely for unaccelerated video playback, including streaming from Youtube and other popular hostings (''ytdl-format=18'' is usually needed)
===== Status =====
==== What works ====
* Booting (currently fetching kernel+rootfs is a bit slow due to u-boot bug, ~15s)
* Display (both text console and X.org fbdev), keyboard, touchpad
* Wifi
* Bluetooth
* GSM/UMTS data transfer
* Stereo sound both on internal speakers and the headphones
* Webcam
* Integrated digital microphone
* External stereo headset with microphone
==== What doesn't ====
* LCD and keyboard in u-boot (pending upstream patches and paz00 integration, http://news.gmane.org/group/gmane.comp.boot-loaders.u-boot/thread=122864, for keyboard NVEC support would be needed)
* Boot from USB in u-boot (http://news.gmane.org/group/gmane.comp.boot-loaders.u-boot/thread=122484)
* Resume from suspend-to-ram (pending u-boot warmboot patches, see http://news.gmane.org/group/gmane.comp.boot-loaders.u-boot/thread=122760)
* Suspend-to-disk/hibernation (not anytime soon, no upstream support for ARMs)
* tegra_wdt watchdog resets the system but it doesn't boot after that for the reasons unknown
* Proprietary drivers for X and OMX-accelerated sound/video decoding (never tried, see https://build.pub.meego.com/package/files?package=nvidia-tegra2&project=home%3Acxl000%3Atrimslice%3AMer%3Atesting , http://ppa.launchpad.net/ac100/ppa/ubuntu/pool/restricted/n/nvidia-graphics-drivers-tegra/ , mplayer-omx, gst-omx etc)
===== Installation and initial configuration story =====
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]].