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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Tumbleweed’ Category

Marrying U-Boot, uEFI and grub2 – Alexander Graf – openSUSE…

Posted by jpluimers on 2020/07/13

A very insightful talk: “Marrying U-Boot, uEFI and grub2 – Alexander Graf – openSUSE…”

Booting is hard. Booting in the ARM world is even harder. State of the art are a dozen different boot loaders that may or may not deserve that name. Each gets configured differently and each has its own pros and cons.

As a distribution this is a nightmare. Configuring each and every one of them complicates code that really should be very simple.

To solve the problem, we can just add another layer of abstraction (grub2) on top of another layer of abstraction (uEFI) on top of another layer of abstraction (u-boot). Follow me on a journey on how all those layers can make life easier for the distribution and how much fun uEFI really is.

After this talk, you will know how ARM systems boot, what uEFI really means, how uEFI binaries interact with firmware and how we are going to move to uEFI based boot on openSUSE for ARM.

Usually known as agraf on-line, [WayBack] Alexander Graf – Open IoT & ELC 2017 is an impressive guy:

Alexander Graf

SUSE
KVM Wizard
Nürnberg Area, Germany
Alexander started working for SUSE about 9 years ago. Since then he worked on fancy things like SUSE Studio, QEMU, KVM and openSUSE on ARM. Whenever something really useful comes to his mind, he tends to implement it. Among others he did Mac OS X virtualization using KVM, nested SVM, KVM on PowerPC and a lot of work in QEMU for openSUSE on ARM. He is the upstream maintainer of KVM for PowerPC, QEMU for PowerPC and QEMU for S390x.

Slides: [WayBack] Marrying U-Boot, UEFI and grub.pdf

There are 2 videos on YouTube (view them below):

A few things I learned

Boot sequence:

  1. Raspberry Pi has a tiny boot ROM
  2. It loads the firmware in the GPU (for Raspberry this is a Raspberry Foundation provided binary)
  3. The firmware loads U-Boot
  4. U-Boot loads grub2
  5. grub2 can have many modules (like file system drivers) and loads the kernel

Alexander pushed the U-Boot stuff up stream, but the FreeBSD team was the first to actually boot a full OS from it.

Relations:

  • uEFI/EFI is a set of specs that define the API
  • U-Boot is the firmware implementing uEFI, so your machine behaves as a PC making booting a lot more standardised, starting at handing off to a regular grub2 boot process
  • U-Boot loads grub2

U-boot:

–jeroen

References:

Images

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Posted in *nix, *nix-tools, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

openSUSE:Standards Rpm Metadata – openSUSE: Repository layout

Posted by jpluimers on 2020/07/09

For my link archive: [WayBack] openSUSE:Standards Rpm Metadata – openSUSE: Repository layout.

It is not fully up to date any more on primary.xml.gz, so here are my notes for the aarch64 version of Tumbleweed:

  1. Inspect http://download.opensuse.org/ports/aarch64/tumbleweed/repo/oss/repodata/repomd.xml [WayBack] for the name of *-primary.xml.gz (in this case http://download.opensuse.org/ports/aarch64/tumbleweed/repo/oss/repodata/d701c298b21d0b995c9560f9cfcc84685cb916deacc4f4c4a613a9b9d8f5aa57-primary.xml.gz [WayBack]
  2. Download that .gz file and uncompress it
  3. Inspect the *-primary.xml from it, look inside the metatadata root element for a package having a name element with value openSUSE-release: that package element now has a version element having a ver attribute containing the version text.

–jeroen

Posted in *nix, *nix-tools, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

Raspberry Pi, Tumbleweed, btrfs

Posted by jpluimers on 2020/06/15

I want to use btrfs as filesystem on a Raspberry Pi with opensuse Tumbleweed.

It is hard to find out how, so here are a few links that should help me from “opensuse” “tumbleweed” “btrfs” “raspberry” pi:

–jeroen


Posted in *nix, *nix-tools, Development, Hardware Development, Linux, openSuSE, Power User, Raspberry Pi, SuSE Linux, Tumbleweed | Leave a Comment »

Raspberry Pi 1B OpenSuSE Tumbleweed zypper upgrade problem · GitHub

Posted by jpluimers on 2020/05/25

It looks like OpenSuSE has stopped supporting Raspberry Pi 1, so the best likely is to recycle it into a Pi-Hole as basically it’s been dead since mid 2017: [WayBack] Raspberry Pi 1B OpenSuSE Tumbleweed zypper upgrade problem · GitHub.

Build status for armv6l support: [WayBack] Project openSUSE:Factory:ARM Status Monitor – openSUSE Build Service

–jeroen

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Posted in *nix, *nix-tools, Debian, Development, Hardware Development, History, Linux, openSuSE, Power User, Raspberry Pi, Raspbian, SuSE Linux, Tumbleweed | Leave a Comment »

ipmi – Linux: Why does Single User mode work on Serial Console but not on the attached Keyboard/Video/Monitor? – Server Fault

Posted by jpluimers on 2020/05/19

From [WayBack] ipmi – Linux: Why does Single User mode work on Serial Console but not on the attached Keyboard/Video/Monitor? – Server Fault (slightly edited; thanks Patrick!):

Because init has not spawned off multiple TTYs yet (getty, mgetty, etc), so you only have the primary TTY. The primary TTY is the last console= parameter on the kernel command line. All the console parameters get the output, but only the last one will be able to act as input.

–jeroen

Posted in *nix, Debian, Linux, openSuSE, Power User, RedHat, SuSE Linux, Tumbleweed | Leave a Comment »

 
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