Coming from BIOS/UEFI systems where it's generally relatively straightforward to boot a generic kernel into a desktop nowadays, #ARM #DeviceTree systems really are a mess...
#DeviceTree
Das einzig gute an der Zeit, die ich da investiert habe, ist die zusätzliche Unterstützung von #DeviceTree File Syntax Coloring aus orgmode Posts, was jetzt auch funktioniert!
Ok, bei 8 Zeilen dts File ist das jetzt noch nicht sooo wichtig, aber cool ist es schon 😂
#orgmode rules!
I couldn't resist to have a quick look into the device tree file(s) in the kernel sources of Bianbu Linux:
see here: https://gitee.com/bianbu-linux/linux-6.6/blob/bl-v2.0.y/arch/riscv/boot/dts/spacemit/k1-x.dtsi
On a quick look (didn't check entry by entry) the 'riscv,isa-extensions' entries per cpu seems to match your table.
Anyway as I said before, I think this does not need to reflect the real capabilities of the SOC too.
#riscv #spacemit #spacemitk1 #spacemitx60 #devicetree #linux #bananapif3 #bpif3
Regarding this I found an article from RedHat:
see https://research.redhat.com/blog/article/risc-v-extensions-whats-available-and-how-to-find-it/
According to the article the DeviceTree can be used to get that information, but since that's just a configuration describing the hardware it could be incomplete too.
#riscv #spacemit #spacemitk1 #bananapif3 #bpif3 #linux #devicetree
"Operating system provided device-trees" by Heinrich Schuchardt
While it was not the initial goal, in practice, when booting Linux, device trees need to be coupled with a given kernel version.
This brings its own sets of challenge, because the bootloader needs to patch the device tree to provide information to the OS.
When using EFI, there is now the EFI_DT_FIXUP_PROTOCOL.
Outside of EFI, the flash-kernel tool helps picking the correct device tree depending on the board model.
The way forward would be to use Unified Kernel Images, which would contain all device trees for supported platform, with the efistub used to select the correct one.
Wrote some words about my experiences with FriendlyELEC NanoPC-T6 SBC.
https://marcin.juszkiewicz.com.pl/2024/08/09/i-had-some-fun-with-friendlyelec-nanopc-t6/
I thought that booting Seriously Bad Computers in ACPI mode is crippled compared to booting in DeviceTree mode.
NanoPC-T6 is otherwise. Same 6.11-rc2 kernel gives working system in ACPI mode and fail-to-boot one in DT.
DT = no USB, no PCIe while rootfs is on NVME cause it worked fine in ACPI mode.
And DT is from 6.11-rc2 kernel.
#SystemNotReady #ACPI #DeviceTree #SBC #RK3588 #FriendlyELEC #NanoPC-T6
Hey fellow #embeddedlinux people! Have you ever wanted to generate a canonical representation of your devicetrees? Or diff two devicetrees? How about adding back labels to a decompiled devicetree? I've polished up and released a little tool I made for these things called DTCanon: https://github.com/mortie/dtcanon
This has been useful for me in some situations. Maybe it'll be useful for you too. It's #FOSS of course.
At Last, Chumby is Ready https://hackaday.com/2024/08/05/at-last-chumby-is-ready/ #Retrocomputing #LinuxHacks #devicetree #chumby #linux
How do I make #deviceTree for an #Android device to custom ROM it.
Драйвер Ethernet для xv6
Xv6 - учебная ОС - рассказывает об идеях, что лежат в основе операционных систем. Научим xv6 работать в сети, познакомимся со стандартом виртуальных устройств VirtIO, деревом устройств DeviceTree, технологией Ethernet, сетевыми протоколами, возведем сетевой мост между виртуальными машинами.
https://habr.com/ru/articles/826500/
#xv6 #ethernet #virtio #devicetree #qemu #dhcp #ipv4 #ipv6 #arp #icmp
Things I would change in the #devicetree syntax if I was god emperor of the world (or at least the embedded Linux part of it):
* Make semicolons after closing curly braces optional (ideally they'd be prohibited but that'd be a breaking change and I'd be a benevolent god emperor)
* Make status = "enabled" a synonym to "ok" or "okay", to match status = "disabled"
These two small changes would remove 99% of the mistakes I make when doing devicetree stuff
@DesRoin there are devices / sensors, for example the #sps30 PM sensors, that supports both #i2c and #uart connections. There are two drivers, one for i2c and one for uart. i2c can be attached in various ways.
But I have no idea how you are supposed to tell linux that behind this USB UART dongle, say /dev/ttyUSB0, is a sps30 that you should talk too with this driver. There is a very simple #devicetree example that does not help at all.
How are you supposed to "attach" #uart based sensor driver to a serial port in #linux when NOT using a #devicetree ? #iio
@CyReVolt gave a talk about "dtvis", a tool to visualize device trees.
So there is this thing that has bothered me since the dawn of time (ok, not that long, but at least since XML schemas): Why would you create a friendly, sensible URI for your schema like "http://devicetree.org/schemas/gpio/gpio-consumer.yaml#", that is practically begging to be clicked, only to have your web server return 404? (same result for https) I am perfectly aware that schema IDs and web links are not the same, but would it kill somebody if they worked like that, just for once? #devicetree
@popey 🤣 i've noticed!
Friggen Copilot sent me down a rabbit hole, suggesting writing&compiling device tree code, in order to define the PPS(Pulse Per Second) pin of my GNSS/GPS NTP server, using a BananaPi SBC - it turned out to be a one-liner, instead …i've wasted a whole day, watching a tech talk and reading #DeviceTree specs …then, a rando from YouTube pointed me in the right direction …at one point copilot even served me my own forum post as a solution! 🤣 😅 (i've figure it out, eventually)
Does anyone here know how to do I2S audio output in #Linux ..? I've enabled an I2S device in #devicetree and and it shows up as /sys/devices/platform/fe480000.i2s, and shows up as using the rockchip-i2s-tdm driver. However, it doesn't show up as an alsa sound card...
CLion Kicks Off Its 2024.1 EAP
#Clang #CLion #Eap #News #20241 #Cmake #Debug #Devicetree #Meson
https://blog.jetbrains.com/clion/2024/01/clion-kicks-off-its-2024-1-eap/
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