[U-Boot] [PATCH v2] arm: socfpga: Enable load zImage and Linux DTB from USB

[Chin Liang See <clsee@altera.com>]

Hi Vagrant,

On Fri, 2015-11-27 at 08:57 -0800, Vagrant Cascadian wrote:
> On 2015-11-27, Marek Vasut wrote:
> > On Friday, November 27, 2015 at 01:23:34 PM, Chin Liang See wrote:
> > > On Fri, 2015-11-27 at 11:36 +0100, Marek Vasut wrote:
> > > > On Friday, November 27, 2015 at 03:36:42 AM, Chin Liang See
> > > > wrote:
> > > > > Adding new environment usbload which will load zImage and
> > > > > Linux DTB from USB mass storage through FAT file system.
> ...
> > > > The distro_bootcmd can do this and even let's you boot
> > > > debian/fedora
> > > > on such
> > > > a machine in a standardized way. Should we switch to
> > > > distro_bootcmd
> > > > instead
> > > > of adding new ad-hoc stuff ?
> > > 
> > > It seems to me that we need to add script into the fs to get that
> > > work,
> > > right?
> 
> Yes and no. Currently Debian uses a bootscript generated with
> flash-kernel, such as:
> 
>   https://anonscm.debian.org/cgit/d-i/flash-kernel.git/tree/bootscrip
> t/all/bootscr.uboot-generic
> 
> But you can also use a syslinux formatted plain text file, such as
> extlinux.conf or pxelinux.conf/default, described in
> u-boot/doc/README.distro. They look something like this:
> 
>   label Boot
>   kernel /boot/vmlinuz
>   append ro root=/dev/sda2 console=ttyS0,115200n8
>   fdtdir /boot/dtbs/
>   initrd /boot/initrd.img
> 
> The (only) reason debian hasn't yet switched to syslinux-style config
> files is that is that the console settings vary wildly by board, and
> the
> "chosen" console property isn't yet consistantly supported on all
> boards
> and kernel versions in use. That may change soon.
> 
> But the distro_bootcmd support supports both syslinux-style files and
> bootscripts out-of-the-box. Because of the standardization, for any
> board you would hope to see working out of the box on Debian(and I
> suspect Fedora as well), supporting distro_bootcmd in u-boot upstream
> would be ideal.
> 
> 
> live well,
>   vagrant


Thanks for the pointers and this looks great. I can imagine how this
cool feature easing user when come to update the boot device and boot
file name without the need to update the U-Boot source.

To take this advantage socfpga, ubifs support for NOR and NAND boot
need to be happened first :)

Thanks
Chin Liang