From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 26 Aug 2016 11:30:22 +0200 Subject: [Buildroot] [PATCH v1 3/9] board/intel/common: Add possibility for adding ACPI tables to the initrd In-Reply-To: <20160826090454.GK1812@lahna.fi.intel.com> References: <1472133887-34746-1-git-send-email-andriy.shevchenko@linux.intel.com> <1472133887-34746-4-git-send-email-andriy.shevchenko@linux.intel.com> <7d61148d-f102-bc79-e177-3ec8f6f95b8e@mind.be> <20160826090454.GK1812@lahna.fi.intel.com> Message-ID: <20160826113022.2748b435@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Fri, 26 Aug 2016 12:04:54 +0300, Mika Westerberg wrote: > > On 25-08-16 16:04, Andy Shevchenko wrote: > > > Add script which takes ASL files as input, compiles them to AML bytecode, > > > and prepends the whole thing to the initrd archive. They are placed in > > > kernel/firmware/acpi directory where the kernel is able to find and use > > > them. > > > > Why is this a post-image script, and not just a post-build script that copies > > everything in the right place and lets the cpio rootfs take care of generating > > the cpio? AFAIK there is no particular requirement for this stuff to be at the > > beginning of the cpio image, is there? > > Actually there is - the kernel looks only from the first uncompressed > cpio archive for these additional AML files. Still not clear: Arnout doesn't suggest to generate multiple cpio archives, but rather to simply have the AML files within the cpio archive in the first place. The Buildroot process looks like this: 1. Build all packages 2. Run post-build scripts 3. Create filesystem images (including cpio one) 4. Run post-image scripts Right now, if I understand correctly, in step (4), you're generating an additional initrd with just the AML files. Is this correct? What about instead having things done in step (2): install the AML files at the appropriate places in $(TARGET_DIR) so that they automatically end up in the rootfs.cpio generated by Buildroot? In this case, there's a single initrd, which contains both the root filesystem itself and the AML files. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com