From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 14 Mar 2018 19:08:30 +0100 From: Greg Kroah-Hartman To: Samuel Holland Cc: linux-kernel@vger.kernel.org, coreboot@coreboot.org, Thierry Escande , Wei-Ning Huang , Julius Werner , Dmitry Torokhov , Guenter Roeck Subject: Re: [PATCH 0/5] coreboot table bus and framebuffer driver Message-ID: <20180314180830.GA6311@kroah.com> References: <20180125014120.20851-1-samuel@sholland.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180125014120.20851-1-samuel@sholland.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Jan 24, 2018 at 07:41:15PM -0600, Samuel Holland wrote: > On many systems, coreboot[1] firmware can initialize graphics hardware > and set up a high-resolution linear framebuffer. It exports information > about this framebuffer, along with various other information, in a table > discoverable via ACPI or a device tree. > > coreboot also supports booting Linux directly from flash as a "payload". > Projects such as Heads[2], u-root[3], and petitboot[4] provide a minimal > userland that can then be used to chainload (via kexec) into a full > Linux system loaded from disk or over the network. > > Fitting even a minimal Linux system on an SPI flash chip is challenging. > Reusing the framebuffer setup from coreboot provides an enormous benefit > to these projects by allowing them to omit full graphics drivers from > their kernel builds. It also speeds up boot times by avoiding duplicated > effort, and because coreboot's graphics initialization is often much > faster than the Linux driver. > > Patch 1 of this series expands coreboot table support into an enumerable > bus that devices can hang off of. Patches 2-3 convert the existing > drivers to use the new bus structure instead of ad-hoc platform devices, > and patch 4 removes the old coreboot_table_find function. > > Finally, patch 5 adds a new driver for the coreboot-initialized > framebuffer. It improves on earlier work[5] by being architecture- > independent and not needing to scan through low memory. > > This patchset has been tested on a Lenovo ThinkPad X220, and earlier > versions of these patches have been tested by various members of the > coreboot community on other hardware. It would be great to get some of the google developers to ack these, as this touches their code... thanks, greg k-h