Re: wip blog post: running Guix System on ARM
On Sun, Nov 17, 2019 at 08:43:33PM +0100, Ludovic Courtès wrote: > Hello! > > Julien Lepiller skribis: > > > Hi, attached is a draft for a blog post (or a section in the cookbook) > > for explaining how to install the Guix System on an ARM board. WDYT? > > I really like it! Yes, it makes we want to try! I think it should be a BLOG AND a section in the cookbook. Pj.
Re: wip blog post: running Guix System on ARM
Hello! Julien Lepiller skribis: > Hi, attached is a draft for a blog post (or a section in the cookbook) > for explaining how to install the Guix System on an ARM board. WDYT? I really like it! Nitpick: s/grub/GRUB/ and s/u-?boot/U-Boot/ (when referring to the software). Perhaps a reference at the end to Danny’s work to follow Buildroot more closely (and to Buildroot itself) would be interesting, but anyhow, it looks very nice! I guess you could post it on Monday noon CET (tomorrow) if you feel ready. Note that you’ll need to adjust the header just like the other .md files in guix-artwork.git/website/posts. Thanks! Ludo’.
Re: wip blog post: running Guix System on ARM
Hi, Pierre Neidhardt skribis: >> ### The kernel modules >> >> In order for Guix to be able to load the system from the initramfs, it will >> probably need > > Maybe define initramfs? Or just link to > https://en.wikipedia.org/wiki/Initramfs. I’d suggest writing “initial RAM disk (initrd)” to (1) be consistent with the terminology used in Guix, and (2) to avoid obscure abbreviations. :-) Ludo’.
Re: wip blog post: running Guix System on ARM
Hello, Danny Milosavljevic skribis: > On Wed, 13 Nov 2019 22:21:54 +0100 > Julien Lepiller wrote: > >> Hi, attached is a draft for a blog post (or a section in the cookbook) >> for explaining how to install the Guix System on an ARM board. WDYT? > > I guess it can't hurt to describe this stuff as it works now, but the goal is > not > to need to do any of this complicated stuff--and there's no fundamental reason > why one would have to. There are projects like buildroot which have all the > u-boot configuration (and more--like the partitioning, which also can > sometimes > have funny requirements, for example on Allwinner) that Guix could import to > generically install Guix on any ARM board. > Eventually there will be an importer for those. Perhaps the closing could link to the work you’ve started in this area and to explain the goals? https://git.savannah.gnu.org/cgit/guix.git/log/?h=wip-buildroot (Was there also a mailing list thread on this topic?) Thanks, Ludo’.
Re: wip blog post: running Guix System on ARM
Le Thu, 14 Nov 2019 12:05:34 +0100, "pelzflorian (Florian Pelz)" a écrit : > On Thu, Nov 14, 2019 at 10:29:22AM +0100, Pierre Neidhardt wrote: > > Neat, thanks for this article! > > > > Yes, thank you! I have not tried yet though. > > Maybe add the top add instructions what to do if installation fails > (i.e. flash the SD with another operating system and start anew). > > > > > Make sure there is an empty /etc, or the new system won't boot > > > properly. > > > > Isn't this a bug in Guix? > > > > > > Is installing on the same drive an “official” installation method? I > mean, it probably works and people can ask for help after using it, > but remaining files from the old system could be problematic. If this > is dangerous (is it?) then please add a warning. It's not officially recommended, but we have used and proposed it on IRC in the past. The overdrive at my place, as well as my own server both were installed using that method. > > Also, I wonder: > > On Wed, Nov 13, 2019 at 10:21:54PM +0100, Julien Lepiller wrote: > > Then, initialize the system with: > > > > ```bash > > mount /dev/sda1 /mnt > > mkdir /mnt/etc > > $EDITOR /mnt/etc/config.scm # create the configuration file > > guix system init /mnt/etc/config.scm /mnt > > ``` > > So the mmcblk you install on is different from the running system’s > mmcblk, otherwise how could you keep your old system’s SD card? > > Then the mmcblk device number will change on the running Guix System > and the config.scm will have to be adapted to use the mmcblk before > reconfiguring from the installed Guix System. > > Otherwise if you install on the same mmcblk as the running system, > then maybe this could fail if the u-boot partition is too small? That > would leave both the existing operating system and the new Guix System > unusable. Maybe there should be more of a warning. > > > ### The bootloader > > > > Because of the way the Guix System is designed, you cannot use an > > already existing bootloader to boot your system: it wouldn't know > > where to look for the kernel, because it doesn't know its store > > path. It wouldn't be able to let you boot older generations > > either. Most boards use the u-boot bootloader, so we will focus on > > that bootloader here. > > > More generally, since no old Guix generation can be selected in pure > u-boot when booting (I think) this warrants more of a warning that one > important feature of Guix is missing. I must have expressed myself badly, sorry. It's perfectly possible to select older generations from u-boot. I was talking about the u-boot from the foreign distro, but I was wrong on that too ^^'. So you can always select an older generation. > > For later: What would a rescue of a broken Guix System look like? I > do not know if all this works better with grub-efi on supported ARM > systems; I have never tried. > > For later, maybe in the manual: Maybe it would be interesting how to > create a reusable SD install image for Guix. I also remember there > were discussions about making ci.guix.gnu.org build a two-part > bootable installation image in the past, one part with a bootloader > for a specific board and another part general for all boards. > > Regards, > Florian
Re: wip blog post: running Guix System on ARM
Hi Julien, On Wed, 13 Nov 2019 22:21:54 +0100 Julien Lepiller wrote: > Hi, attached is a draft for a blog post (or a section in the cookbook) > for explaining how to install the Guix System on an ARM board. WDYT? I guess it can't hurt to describe this stuff as it works now, but the goal is not to need to do any of this complicated stuff--and there's no fundamental reason why one would have to. There are projects like buildroot which have all the u-boot configuration (and more--like the partitioning, which also can sometimes have funny requirements, for example on Allwinner) that Guix could import to generically install Guix on any ARM board. Eventually there will be an importer for those. The kernel module situation is awful. It would be good if we could automate it more in the future (if the information is statically available in the first place). If the foreign distribution doesn't have it, not much can be done. I'm not sure what buildroot does--whether we have kernels with different built-in modules for different modules or what? Some comments on your draft: (1) You absolutely can use an existing u-boot to boot Guix (bugs nonwithstanding). Guix only generates "extlinux.conf" and doesn't touch the other u-boot config. The default u-boot-bootloader installer (as opposed to config installer) is "do nothing". So your existing u-boot (for example in NAND flash) would display a boot menu and then you could boot from SSD or SD, for example. If this doesn't work, please file a bug report. Also, the old generations should be able to be selected, too. Doesn't it work? FWIW, I'm also using an existing Grub inside Libreboot to boot Guix on X86, with exactly the same mechanism (grub.conf generated, grub-install not invoked). (2) If possible, can you mention that non-exported, non-documented variables are subject to change? I mean I like that "@@" is possible, but let's make sure the user knows that it would be better to contact us for including his stuff if it's supposed to continue to work. pgpMg3GLHY34d.pgp Description: OpenPGP digital signature
Re: wip blog post: running Guix System on ARM
On Thu, Nov 14, 2019 at 10:29:22AM +0100, Pierre Neidhardt wrote: > Neat, thanks for this article! > Yes, thank you! I have not tried yet though. Maybe add the top add instructions what to do if installation fails (i.e. flash the SD with another operating system and start anew). > > Make sure there is an empty /etc, or the new system won't boot > > properly. > > Isn't this a bug in Guix? > > Is installing on the same drive an “official” installation method? I mean, it probably works and people can ask for help after using it, but remaining files from the old system could be problematic. If this is dangerous (is it?) then please add a warning. Also, I wonder: On Wed, Nov 13, 2019 at 10:21:54PM +0100, Julien Lepiller wrote: > Then, initialize the system with: > > ```bash > mount /dev/sda1 /mnt > mkdir /mnt/etc > $EDITOR /mnt/etc/config.scm # create the configuration file > guix system init /mnt/etc/config.scm /mnt > ``` So the mmcblk you install on is different from the running system’s mmcblk, otherwise how could you keep your old system’s SD card? Then the mmcblk device number will change on the running Guix System and the config.scm will have to be adapted to use the mmcblk before reconfiguring from the installed Guix System. Otherwise if you install on the same mmcblk as the running system, then maybe this could fail if the u-boot partition is too small? That would leave both the existing operating system and the new Guix System unusable. Maybe there should be more of a warning. > ### The bootloader > > Because of the way the Guix System is designed, you cannot use an already > existing bootloader > to boot your system: it wouldn't know where to look for the kernel, because > it doesn't know > its store path. It wouldn't be able to let you boot older generations > either. Most boards > use the u-boot bootloader, so we will focus on that bootloader here. More generally, since no old Guix generation can be selected in pure u-boot when booting (I think) this warrants more of a warning that one important feature of Guix is missing. For later: What would a rescue of a broken Guix System look like? I do not know if all this works better with grub-efi on supported ARM systems; I have never tried. For later, maybe in the manual: Maybe it would be interesting how to create a reusable SD install image for Guix. I also remember there were discussions about making ci.guix.gnu.org build a two-part bootable installation image in the past, one part with a bootloader for a specific board and another part general for all boards. Regards, Florian
Re: wip blog post: running Guix System on ARM
Hi, Thank you for the article! I would find interesting to point somewhere in your post to these previous blog posts [1] [2] [3] about ARM and Guix. :-) [1] https://guix.gnu.org/blog/2017/porting-guixsd-to-armv7/ [2] http://guix.gnu.org/blog/2018/guix-on-android/ [3] http://guix.gnu.org/blog/2019/guix-days-bootstrapping-arm/ à tantôt, simon
Re: wip blog post: running Guix System on ARM
Hi Julien,
Julien Lepiller writes:
> Hi, attached is a draft for a blog post (or a section in the cookbook)
> for explaining how to install the Guix System on an ARM board. WDYT?
LOL! \O/
This should be a cookbook section, and released soon unless other people
find some error or important things missing (I still do not use some ARM
SoC, but hope to test soon)
What about to start a wip-cookbook-install-on-arm branch with a 1/2
weeks time frame to allow patch proposals from interested
parties?... then publish? :-)
I have just a couple of comments and one typo... BTW discussion based on
my comments should be postponed after your section is published in the
cookbook, since I don't have patch proposals :-D
[...]
> Most boards can be booted from an existing GNU+Linux distribution. You will
> need to install a distribution (any of them) and install GNU Guix on it, using
> e.g. the installer script.
Is it possible to install to SDD (eventually with external HDD) using
another host (e.g. my laptop) with `guix system disk-image...` and then
``dd ... of=/dev/sdX`` on SDD?
[...]
> ### The kernel modules
[...]
AFAIU this is the only "tricky" part for the user: can we find a way for
Guix to help them automagically populate the list of needed initrd
kernel modules for their SoC?
> Your own board may need other kernel modules to boot properly, however it is
> hard to discover
> them. Guix can tell you when a module is missing in your configuration file
> if it is loaded
> as a module. Most distros however build these modules in the kernel
> directly, so Guix cannot
> detect them reliably. Another way to find what drivers might be needed is to
> look at the output
> of `dmesg`. You'll find messages such as:
This implies that we are booting a distro on the SoC, so (if possible)
we cannot install using `guix system disk-image`. This means that the
only way to make Guix automagically know the list of base modules needed
for each SoC should be to... define them in Guix.
Should be possible to extend (gnu system linux-initrd) whith code
defining default-initrd-modules if string-match some specific SoC
architectures (are they detected?) ?
--8<---cut here---start->8---
(define* (default-initrd-modules
#:optional
(system (or (%current-target-system)
(%current-system
"Return the list of modules included in the initrd by default."
(define virtio-modules
;; Modules for Linux para-virtualized devices, for use in QEMU guests.
'("virtio_pci" "virtio_balloon" "virtio_blk" "virtio_net"
"virtio_console" "virtio-rng"))
`("ahci" ;for SATA controllers
"usb-storage" "uas" ;for the installation image etc.
"usbhid" "hid-generic" "hid-apple" ;keyboards during early boot
"dm-crypt" "xts" "serpent_generic" "wp512" ;for encrypted root partitions
"nls_iso8859-1";for `mkfs.fat`, et.al
,@(if (string-match "^(x86_64|i[3-6]86)-" system)
'("pata_acpi" "pata_atiixp";for ATA controllers
"isci") ;for SAS controllers like Intel C602
'())
,@virtio-modules))
--8<---cut here---end--->8---
I mean something like adding a proper form of this pseudocode:
--8<---cut here---start->8---
,@(if (string-match "^()-" system)
'("sd_mod" "ahci_sunxi";for sunxi ATA controller
"sunxi-mmc") ;for sunxi MMC
'())
--8<---cut here---end--->8---
Obviously there should be quite some work to do to extend our
default-initrd-modules this way for each SoC (or class of SoCs) since we
should find them reading some appropriate documentation or testing
things like you described in this draft, but once done it's forever and
for all :-)
> Installing the Guix System
> --
[...]
> In this scenario, we use the foreign system as we would the installer iso,
> using the manual
> installation procedures described in the manual. Essentially, you have to
> partition your SSD
> to your liking, format your new partations and make sure to reference the
> correct partition
^ i (typo)
[...]
Thanks! Gio'
--
Giovanni Biscuolo
Xelera IT Infrastructures
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wip blog post: running Guix System on ARM
Hi, attached is a draft for a blog post (or a section in the cookbook) for explaining how to install the Guix System on an ARM board. WDYT? Guix on an ARM Board Increasingly people discovering Guix want to try it on an ARM board, instead of their x86 computer. There might be various reasons for that, from power consumption to security. In my case, I found these ARM boards practical for self-hosting, and I think the unique properties of GNU Guix are making it very suitable for that purpose. I have installed GNU Guix on a Cubietruck, so my examples below will be about that board. However, you should be able to change the examples for your own use case. Installing the Guix System on an ARM board is not as easy as installing it on an x86 desktop computer: there is no installation image. However, Guix supports ARM and can be installed on a foreign distribution running on that architecture. The trick is to use the Guix installed on that foreign distribution to initialize the Guix System. Most boards can be booted from an existing GNU+Linux distribution. You will need to install a distribution (any of them) and install GNU Guix on it, using e.g. the installer script. Then, my plan was to install the Guix System on an external SSD drive, instead of the SD card, but we will see that both are perfectly possible. The first part of the article will focus on creating a proper u-boot configuration and an operating system declaration that suits your board. The second part of this article will focus on the installation procedure, when there is no installer working for your system. Writing a configuration file for an ARM board - A configuration file for an ARM board is not very different from a configuration file for a desktop or a server running on another architecture. However, most boards use the u-boot bootloader and require some less common modules to be available at boot time. ### The root file system First of all, you should decide where your root file system is going to be installed. In my case, I wanted to install is on the external SSD, so I chose it: ```scheme (file-systems (cons* (file-system (mount-point "/") (device "/dev/sda1") (type "ext4")) %base-file-systems)) ``` If you instead want to install the root file system on an SD card, you'll need to find its device name, usually `/dev/mmcblk0` and the partition number. The device corresponding to the first partition should be `/dev/mmcblk0p1`. In that case, you would have: ```scheme (file-systems (cons* (file-system (mount-point "/") (device "/dev/mmcblk0p1") (type "ext4")) %base-file-systems)) ``` ### The bootloader Because of the way the Guix System is designed, you cannot use an already existing bootloader to boot your system: it wouldn't know where to look for the kernel, because it doesn't know its store path. It wouldn't be able to let you boot older generations either. Most boards use the u-boot bootloader, so we will focus on that bootloader here. Contrary to grub, there are multiple variants of u-boot, one per board type. The installation procedure for u-boot is also somewhat specific to the board, so there are two things that you need to take care of: the u-boot package and the bootloader declaration. Guix already define a few u-boot based bootloaders, such as `u-boot-a20-olinuxino-lime-bootloader` or `u-boot-pine64-plus-bootloader` among others. If your board already has a `u-boot-*-bootloader` defined in `(gnu bootloader u-boot)`, you're lucky and you can skip this part of the article! Otherwise, maybe the bootloader package is defined in `(gnu packages bootloaders)`, such as the `u-boot-cubietruck` package. If so, you're a bit lucky and you can skip creating your own package definition. If your board doesn't have a `u-boot-*` package defined, you can create one. It could be as simple as `(make-u-boot-package "Cubietruck" "arm-linux-gnueabihf")`. The first argument is the board name, as expected by the u-boot build sysetem. The second argument is the target triplet that corresponds to the architecture of the board. You should refer to the documentation of your board for selecting the correct values. If you're really unlucky, you'll need to do some extra work to make the u-boot package you just created work, as is the case for the `u-boot-puma-rk3399` for instance: it needs additional phases to install firmware. You can add the package definition to your operating system configuration file like so, before the operating-system declaration: ```scheme (use-modules (gnu packages bootloaders)) (define u-boot-my-board (make-u-boot-package "Myboard" "arm-linux-gnueabihf")) (operating-system [...]) ``` Then, you need to define the bootloader. A bootloader is a structure that has a name, a package, an installer, a configuration file and a configuration file
