From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnab Basu Date: Thu, 14 Aug 2014 14:57:21 +0530 Subject: [U-Boot] Passing bootargs to arm64 kernel In-Reply-To: References: <20140813103908.GB19374@bill-the-cat> Message-ID: <53EC80F9.3060303@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 08/14/2014 08:04 AM, Youngmin Nam wrote: > Thank you for reply Tom, > Let me ask you some questions. > > Can we set kernel's bootargs without re-compiling device tree on arm64 > kernel by u-boot? > > I mean, I want to set kernel's bootargs by u-boot without re-compiling > device tree. > > Is it possible? This is done anyway, whatever is defined in CONFIG_BOOTARGS will be stored in the U-Boot environment variable bootargs and passed as bootargs to the kernel via the "chosen" node. See fdt_chosen in common/fdt-support.c. So if you want the change the bootargs passed to the kernel, just do > set bootargs '' at the u-boot prompt and the boot the kernel. Thanks Arnab > 2014. 8. 13. ?? 7:39? "Tom Rini" ?? ??: > >> On Wed, Aug 13, 2014 at 11:21:32AM +0900, Youngmin Nam wrote: >> >>> Hello. >>> I'm trying to find a way how to pass bootargs to arm64 kernel. >>> >>> In arm32 kernel, we can pass bootargs with atag from u-boot to kernel. >> So, >>> we can overwrite kernel's bootargs with u-boot's bootargs. >>> >>> But from arm64 kernel, the dtb is the only argument that should be passed >>> from bootloader which is mandatory. >>> you can find this contents in kernel >>> documentation.(Documentation/arm64/Booting.txt) >>> >>> So, is there any way how to set bootargs by u-boot? >> >> Yes, within the device tree, like we do today. There's a few issues we >> have today, but I need to re-post the booti command support patches, >> given what's coming in 3.17 in the kernel. >> >> -- >> Tom >>