Patchwork [v1] dts: tegra-ventana: use proper root instead of /dev/ram

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Submitter Varun Wadekar
Date Nov. 15, 2011, 6:21 a.m.
Message ID <1321338087-3662-1-git-send-email-vwadekar@nvidia.com>
Download mbox | patch
Permalink /patch/125675/
State New, archived
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Comments

Varun Wadekar - Nov. 15, 2011, 6:21 a.m.
From: Pritesh Raithatha <praithatha@nvidia.com>

The root file system on ventana resides on /dev/mmcblk0p1.
Update the dts file to use the proper root instead of /dev/ram.

Signed-off-by: Pritesh Raithatha <praithatha@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
---
 arch/arm/boot/dts/tegra-ventana.dts |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Stephen Warren - Nov. 15, 2011, 7:16 p.m.
Varun Wadekar wrote at Monday, November 14, 2011 11:21 PM:
> From: Pritesh Raithatha <praithatha@nvidia.com>
> 
> The root file system on ventana resides on /dev/mmcblk0p1.

Well, that's entirely up to however the user set up their system, although
I admit mmcblk0p1 is likely to be the common case; I certainly carry
basically this patch locally for many boards.

> Update the dts file to use the proper root instead of /dev/ram.
> 
> Signed-off-by: Pritesh Raithatha <praithatha@nvidia.com>
> Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

Acked-by: Stephen Warren <swarren@nvidia.com>

Of course, perhaps an even better solution is to just remove /chosen from
all the board .dts files, and stop using CONFIG_APPENDED_DTB since U-boot
supports FDT, and will update the cmdline with whatever the user chose.
Still, I think this is probably OK for now.
Olof Johansson - Nov. 21, 2011, 12:49 a.m.
On Tue, Nov 15, 2011 at 11:16:51AM -0800, Stephen Warren wrote:
> Varun Wadekar wrote at Monday, November 14, 2011 11:21 PM:
> > From: Pritesh Raithatha <praithatha@nvidia.com>
> > 
> > The root file system on ventana resides on /dev/mmcblk0p1.
> 
> Well, that's entirely up to however the user set up their system, although
> I admit mmcblk0p1 is likely to be the common case; I certainly carry
> basically this patch locally for many boards.
> 
> > Update the dts file to use the proper root instead of /dev/ram.
> > 
> > Signed-off-by: Pritesh Raithatha <praithatha@nvidia.com>
> > Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
> 
> Acked-by: Stephen Warren <swarren@nvidia.com>
> 
> Of course, perhaps an even better solution is to just remove /chosen from
> all the board .dts files, and stop using CONFIG_APPENDED_DTB since U-boot
> supports FDT, and will update the cmdline with whatever the user chose.
> Still, I think this is probably OK for now.

Actually, removing the default root path is probably a better idea, since it
will vary from installation to installation and doesn't make sense to hard
code.

There's two ways to solve this with u-boot:

* Boot with an u-boot that knows how to pass a device tree (and add the
  bootargs to it before launching the kernel, and do so by either booting
  a fitImage or by loading the device tree explicitly.

* Use the appended-dtb kernel format, and select the ARM_ATAG_DTB_COMPAT
  option. That will mean that the bootargs passed in from atags are moved over
  to the device tree.

So, I would rather see a patch removing the root= argument alltogether.


Thanks!

-Olof
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Stephen Warren - Nov. 21, 2011, 4:56 p.m.
Olof Johansson wrote at Sunday, November 20, 2011 5:50 PM:
> On Tue, Nov 15, 2011 at 11:16:51AM -0800, Stephen Warren wrote:
> > Varun Wadekar wrote at Monday, November 14, 2011 11:21 PM:
> > > From: Pritesh Raithatha <praithatha@nvidia.com>
> > >
> > > The root file system on ventana resides on /dev/mmcblk0p1.
...
> Actually, removing the default root path is probably a better idea, since it
> will vary from installation to installation and doesn't make sense to hard
> code.
...
> So, I would rather see a patch removing the root= argument alltogether.

OK, I'll whip up a patch for that along with a few other minor DTS fixes.

Patch

diff --git a/arch/arm/boot/dts/tegra-ventana.dts b/arch/arm/boot/dts/tegra-ventana.dts
index 9b29a62..5f7fe74 100644
--- a/arch/arm/boot/dts/tegra-ventana.dts
+++ b/arch/arm/boot/dts/tegra-ventana.dts
@@ -8,7 +8,7 @@ 
 	compatible = "nvidia,ventana", "nvidia,tegra20";
 
 	chosen {
-		bootargs = "vmalloc=192M video=tegrafb console=ttyS0,115200n8 root=/dev/ram rdinit=/sbin/init";
+		bootargs = "vmalloc=192M video=tegrafb console=ttyS0,115200n8 root=/dev/mmcblk0p1 rw rootwait";
 	};
 
 	memory {