From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 23 Mar 2018 21:17:35 +0100 Subject: [Buildroot] [At91Bootstrap3] Overriding dtb chosen arguments for kernel command line In-Reply-To: References: Message-ID: <20180323211735.32c114db@windsurf> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Fri, 23 Mar 2018 16:15:32 -0300, Alejandro Ariel Fachini wrote: > I have been using at91bootstrap3 to directly load kernel, using dtb on > sam9x35ek, this kernel is mounting UBI RFS file. > Wel i need to mount another file JFFS2 and i want to change parameters in > Kernel Command Line. > I treid from inside at91bootstrap3-v3.8.6 terminal using make menuconfig > and selecting override kernel comand line but got error. > Also tried manually changing arguments in linux menu config and still get > the arguments inside DTB. > How can i do this? Thank you very much. > Note: I am not using U-Boot, using U-Boot is working ok. Do you have CONFIG_ARM_ATAG_DTB_COMPAT enabled in your kernel configuration ? I suppose when you boot with U-Boot, U-Boot patches the DTB before passing it to the kernel. However, I don't think at91bootstrap3 patches the DTB, it probably just passes an old style ATAGS, which the kernel will only pick up if CONFIG_ARM_ATAG_DTB_COMPAT=y. Note: this is just an hypothesis, I haven't actually checked the at91bootstrap3 code. Best regards, Thomas Petazzoni -- Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com