Hi Stephen,
On Thu, May 31, 2012 at 5:00 PM, Stephen Warren swarren@wwwdotorg.orgwrote:
On 05/31/2012 05:39 PM, Simon Glass wrote:
Hi Stephen,
On Thu, May 24, 2012 at 2:38 PM, Stephen Warren <swarren@wwwdotorg.org mailto:swarren@wwwdotorg.org> wrote:
From: Stephen Warren <swarren@nvidia.com <mailto:swarren@nvidia.comAcked-by: Simon Glass <sjg@chromium.org mailto:sjg@chromium.org>
But a question - what happens if we have a partition table and filesystems on the eMMC - i.e. if we are not actually booting from eMMC?
The eMMC is divided into:
- Boot block 0, 512K
- Boot block 1, 512K
- Main area, the rest
This patch stores the environment at the end of boot block 1.
OK, I suppose this depends on the device, but these are the devices that are soldered down on these boards. Bear in mind we might use the fdt to select between board variants, but ok.
The Linux kernel sees each of those 3 areas as separate block devices (and indeed the 2 boot blocks are read-only by default and require sysfs writes to enable writing). As such, any partition table etc. would be confined to the main area. So, there should be no conflict between PT/FS and saved environment.
SD cards don't have these separate areas, and it may even be optional on eMMC. Still, the Seaboard/Springbank eMMC has these separate blocks.
Thanks for the explanation, that sounds fine.
Regards, Simon