Linux kernel source tree
bebe35bb73
I still have some Soekris net4826 in a Community Wireless Network I volunteer with. These devices use an AMD SC1100 SoC. I am running OpenWrt on them, which uses a patched kernel, that naturally has evolved over time. I haven't updated the ones in the field in a number of years (circa 2017), but have one in a test bed, where I have intermittently tried out test builds. A few years ago, I noticed some trouble, particularly when "warm booting", that is, doing a reboot without removing power, and noticed the device was hanging after the kernel message: [ 0.081615] Working around Cyrix MediaGX virtual DMA bugs. If I removed power and then restarted, it would boot fine, continuing through the message above, thusly: [ 0.081615] Working around Cyrix MediaGX virtual DMA bugs. [ 0.090076] Enable Memory-Write-back mode on Cyrix/NSC processor. [ 0.100000] Enable Memory access reorder on Cyrix/NSC processor. [ 0.100070] Last level iTLB entries: 4KB 0, 2MB 0, 4MB 0 [ 0.110058] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0 [ 0.120037] CPU: NSC Geode(TM) Integrated Processor by National Semi (family: 0x5, model: 0x9, stepping: 0x1) [...] In order to continue using modern tools, like ssh, to interact with the software on these old devices, I need modern builds of the OpenWrt firmware on the devices. I confirmed that the warm boot hang was still an issue in modern OpenWrt builds (currently using a patched linux v6.6.65). Last night, I decided it was time to get to the bottom of the warm boot hang, and began bisecting. From preserved builds, I narrowed down the bisection window from late February to late May 2019. During this period, the OpenWrt builds were using 4.14.x. I was able to build using period-correct Ubuntu 18.04.6. After a number of bisection iterations, I identified a kernel bump from 4.14.112 to 4.14.113 as the commit that introduced the warm boot hang. |
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.