Patrick Georgi has uploaded this change for review.
Documentation: describe coreboot on the dev site's landing page
Get some content on the documentation site's front page. Some links
still need to be filled in with content yet to be written, but we need
to start somewhere.
Change-Id: I7f36234ef783e041a44590858bb75a69b96ee668
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
---
M Documentation/index.md
1 file changed, 134 insertions(+), 0 deletions(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/27/31127/1
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[Documentation](https://review.coreboot.org/cgit/coreboot.git/tree/Documentation)
directory in the source code.
+## Purpose of coreboot
+
+coreboot is a project to develop open source firmware for various
+architectures. Its design philosophy is to do the bare minimum necessary to
+ensure that hardware is usable and then pass control to a different program
+that called the _payload_.
+
+### Separation of concerns
+
+The payload can then provide user interfaces, file system drivers,
+various policies etc. to load the OS. Through this separation of concerns
+coreboot maximizes reusability of the complicated and fundamental hardware
+initialization routines across many different use cases, no matter if
+they provide standard interfaces or entirely custom boot flows.
+
+Popular [payloads]() in use with coreboot are SeaBIOS, which provides PCBIOS
+services, Tianocore, which provides UEFI services, GRUB2, the bootloader
+used by many Linux distributions, or depthcharge, a custom boot loader
+on Chromebooks.
+
+### No resident services (if possible)
+
+Ideally coreboot completely hands over control to the payload with no
+piece of coreboot remaining resident in the system, or even available
+for callback. Given the reality of contemporary computer design,
+there's often a small piece that survives for the whole runtime of
+the computer. It runs in a highly privileged CPU mode (eg SMM on x86)
+and provides some limited amount of services to the OS. But here, too,
+coreboot aims to keep everything at the minimum possible, both in scope
+(eg. services provided) and code size.
+
+### No specification of its own
+
+coreboot uses a very minimal interface to the payload, and otherwise
+doesn't impose any standards on the ecosystem. This is made possible by
+separating out concerns (interfaces and resident services are delegated
+to the payload), but it's also a value that is deeply ingrained in the
+project. We fearlessly rip out parts of the architecture and remodel it
+when a better way of doing the same was identified.
+
+### One tree for everything
+
+Another difference to various other firmware projects is that we try
+to avoid fragmentation: the traditional development model of firmware
+is one of "set and forget" in which some code base is copied, adapted
+for the purpose at hands, shipped and only touched again if there's an
+important fix to do.
+
+All newer development happens on another copy of some code base without
+flowing back to any older copy, and so normally there's a huge amount
+of fragmentation.
+
+In coreboot, we try to keep everything in a single source tree, and
+lift up older devices when we change something fundamentally. That way,
+new and old devices benefit alike from new development in the common parts.
+
+There's a downside to that: Some devices might have no maintainer anymore
+who could ensure that coreboot is still functional for them after a big
+rework, or maybe a rework even requires knowledge that doesn't exist
+anymore within the project (for example because the developer moved on
+to do something else).
+
+In this case, we announce the deprecation of the device and defer the big
+rework until the deprecation period passed, typically 6-12 months. This
+gives interested developers a chance to step in and bring devices up to
+latest standards.
+
+While without this deprecation mechanism we could inflate the number
+of supported devices (probably 300+), only a tiny fraction of them
+would even work, which helps nobody.
+
+## Scope of the coreboot project
+
+coreboot as a project is closer to the Linux kernel than to most
+user level programs. One place where this becomes apparent is the
+distribution mechanism: The project itself only provides source code
+(plus redistributable binaries for parts that we haven't managed to open
+up) and does not ship ready-to-install coreboot-based firmware binaries.
+
+There are various [distributions](), some shipping coreboot with their hardware
+(eg. Purism or Chromebooks), others providing after-market images for
+various devices (eg. Libreboot, MrChromebox).
+
+If you want to use coreboot on your system, that's great!
+
+Please note that the infrastructure around coreboot.org is built for
+development purposes. We gladly help out users through our communication
+channels, but we also expect a "firmware developer mindset": If compiling
+your own firmware and, at some point, recovering from a bad flash by
+hooking wires onto chips in your computer sounds scary to you, you're
+right, as it is.
+
+If that's _way_ beyond your comfort zone, consider looking into the
+various distributions, as they typically provide pre-tested binaries
+which massively reduces the risk that the binary you write to flash is
+one that won't boot the system (with the consequence that to get it to work
+again, you'll need to attach various tools to various chips)
+
+## The coreboot community
+
+If you're interested in getting your hands dirty (incl. potentially wiring
+up an external flasher to your computer), you've come to the right place!
+
+We have various [virtual sites]() where we discuss and coordinate
+our activities, review patches, and help out each other. To
+help promote a positive atmosphere, we established a [Code of
+Conduct](code_of_conduct.md). We invested a lot of time to balance it out,
+so please keep it in mind when engaging with the coreboot community.
+
+Every now and then, coreboot is present in one way or another at
+[conferences](). If you're around, come and say hello!
+
+## Getting the source code
+
+coreboot is primarily developed in the
+[git](https://review.coreboot.org/cgit/coreboot.git) DSCM, using
+[Gerrit](https://review.coreboot.org) to manage contributions and
+code review.
+
+In general we try to keep the `master` branch in the repository functional
+for all hardware we support. So far, the only guarantee we can make is
+that the master branch will (nearly) always build for all boards in a
+standard configuration.
+
+However we're continually working on improvements to our infrastructure to
+get better in that respect, eg by setting up boot testing facilities. This
+is obviously more complex than regular integration testing, so progress
+is slow.
+
+We also schedule two source code releases every year, around April and
+October. These releases see some very limited testing and mostly serve
+as synchronization points for deprecation notices and for other projects
+such as external distributions.
+
Contents:
* [Getting Started](getting_started/index.md)
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