From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Nelson Date: Wed, 19 Feb 2014 12:02:22 -0700 Subject: [U-Boot] [RFC PATCH 1/3] add file with a default boot environment based heavily on Stephen Warrens recent tegra work. In-Reply-To: <5304FE7E.2060805@wwwdotorg.org> References: <1392659798-1665-1-git-send-email-dennis@ausil.us> <1392659798-1665-2-git-send-email-dennis@ausil.us> <5304FB87.3020208@ti.com> <5304FC99.8070009@wwwdotorg.org> <5304FD57.3040508@ti.com> <5304FE7E.2060805@wwwdotorg.org> Message-ID: <5304FFBE.7080104@boundarydevices.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 02/19/2014 11:57 AM, Stephen Warren wrote: > On 02/19/2014 11:52 AM, Dan Murphy wrote: >> On 02/19/2014 12:48 PM, Stephen Warren wrote: >>> On 02/19/2014 11:44 AM, Dan Murphy wrote: >>>> On 02/17/2014 11:56 AM, Dennis Gilmore wrote: >>>>> Signed-off-by: Dennis Gilmore >>>>> diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h >>>>> +#ifdef CONFIG_CMD_USB >>>>> +#define BOOTCMD_INIT_USB "run usb_init; " >>>>> +#define BOOTCMDS_USB \ >>>>> + "usb_init=" \ >>>>> + "if ${usb_need_init}; then " \ >>>>> + "set usb_need_init false; " \ >>>>> + "usb start 0; " \ >>>>> + "fi\0" \ >>>>> + \ >>>>> + "usb_boot=" \ >>>>> + "setenv devtype usb; " \ >>>>> + BOOTCMD_INIT_USB \ >>>>> + "if usb dev ${devnum}; then " \ >>>> This may have already been highlighted but I don't see where the kernel command line arguments can be set. >>>> If you have the file system on the USB stick won't you need to direct the root to the stick? >>> They would be set in boot.scr or extlinux.cfg on the disk that the >>> system boots from; the kernel cmdline is part of the OS that's installed >>> there, not part of U-Boot. This is why these boot scripts load a >>> script/config-file from the disk which in turn defines which >>> kernel/DTB/cmdline to use, rather than directly loading a kernel and >>> DTB. This approach should even be suitable for booting a non-Linux-OS, >>> with suitable commands in boot.scr. >> >> But shouldn't the config file just be an override? >> >> I don't know if we should be having to need to load a boot.scr or any config file just to get the kernel to boot. >> >> If no config file exists should we not try to default to a known good default tested case? > > I believe always loading a script/config-file is the simplest and most > flexible approach, for a *distro* *oriented* boot process. +1 Scripts have the benefit of putting everything into a relatively easy-to-read form that only uses documented U-Boot commands, not board-specific constructs.