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| author | Jesse Barnes <jsbarnes@google.com> | 2021-01-20 16:45:47 -0800 |
|---|---|---|
| committer | Jesse Barnes <jsbarnes@google.com> | 2021-01-20 16:45:47 -0800 |
| commit | f645685e2f2c97b1b60df186f031eca23bf09df1 (patch) | |
| tree | 0ae2d9dd70876ed0bb23966cf78b246be43ea64a | |
| parent | e2c6ceee7b40e344278cf541fbe3339ba699de9a (diff) | |
| -rw-r--r-- | README.txt | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/README.txt b/README.txt new file mode 100644 index 0000000..4811725 --- /dev/null +++ b/README.txt @@ -0,0 +1,56 @@ +Upstream kernels on Chromebooks
+You may want to run a stock upstream kernel on a Chromebook running ChromeOS for a variety of reasons:
+* Testing and development of upstream patches
+* Pushing upstream patches
+* Doing upstream development
+* Doing distro development on a Chromebook
+To that end, I think it’s nice to be able to work in a regular, upstream git kernel tree and be able to easily push your kernel over to a target device for development and testing. Further, using the stock Chromebook firmware and boot method (vboot) is desirable for reasons of test coverage, consistency of experience, and general Chromeyness.
+
+
+The high level requirements for this are similar to many other development activities:
+* Chromebook in developer mode
+* ssh access to the target device
+* Workstation with kernel sources
+* vboot-kernel-utils on the workstation
+
+
+On a high level, the steps required are the following:
+1. Build your kernel with an appropriate config and necessary patches (see appendix)
+2. Copy modules to the target device
+3. Build the new kernel image, including command line, signing, and boot stub
+4. Install the new image
+5. Set the new image to boot once
+
+
+The script in the appendix will perform these steps for you and is provided as a reference.
+________________
+Appendix A - command line and config
+
+
+A sample command line is included in the repo:
+
+
+loglevel=7
+init=/sbin/init
+root=/dev/nvme0n1p3
+rootwait
+rw
+i915.modeset=1
+
+
+It will depend on your specific platform (some will have root on /dev/mmc* for example, or not use the i915 graphics driver.
+
+
+The kernel configuration to use will depend on the platform as well, but options like CONFIG_VT and FRAMEBUFFER should be disabled if booting Chrome OS. See this example config for reference.
+
+
+See example hatch config in this dir.
+
+
+On Chrome OS, the current config can also be retrieved using “modprobe configs” and then reading /proc/config.gz.
+________________
+Appendix B - Scripts
+git://people.freedesktop.org/~jbarnes/cros-misc
+
+
+Use the push_kernel.sh script to upload a kernel from your current working directory (which should be a kernel tree) to the target system. The target has to be in developer mode with ssh access, and you’ll also need to provide a kernel boot command line. You can base your command line on /proc/cmdline from the running system.
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