From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Tue, 1 Sep 2015 08:56:38 +0200 Subject: [Buildroot] First rootfile system build using buildroot In-Reply-To: <944894A3EB1D044A9003B2F944389BB20474C3452F@svr-wa-exch1.atg.lc> References: <944894A3EB1D044A9003B2F944389BB20474C344F7@svr-wa-exch1.atg.lc> <944894A3EB1D044A9003B2F944389BB20474C3452F@svr-wa-exch1.atg.lc> Message-ID: <20150901085638.774989e3@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 Mon, 31 Aug 2015 13:58:04 -0700, Lee, Tommy wrote: > Building the rootfilesystem into zImage resolves the rootfilesystem > loading/linking issue clearly. I do not see any reason to build and > load the rootfilesystem independently. If by "building the root filesystem into zImage" you mean using the initramfs mechanism, then clearly there is a reason to have the root filesystem independently. The initramfs mechanism is OK when the filesystem is relatively small. When it starts to be bigger, then initramfs has a number of drawbacks: * The entire root filesystem must be loaded at boot time. If you have a 5 or 6 MB root filesystem, that's probably alright. But if you have a 100-200 MB root filesystem, then it's going to take a while. By using a normal root filesystem, it gets mounted at boot time, but not its entire contents are loaded into memory at boot time. * The entire root filesystem will always be in memory, consuming this memory. Again if your filesystem is 5, 6, 8 or 16 MB, this might be alright. But if your filesystem is 100-200 MB, you probably don't want those 100-200 MB to be permanently loaded into memory. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com