Re: [Question] Any restriction for the location of initramdisk?

From: Jon Medhurst (Tixy)
Date: Fri Jan 08 2016 - 05:24:07 EST

On Fri, 2016-01-08 at 16:16 +0900, Masahiro Yamada wrote:
> Hi.
> I know DTB should be located within the reach of the kernel
> so that the kernel can get access to it at the early boot stage.
> In other words, DTB should be put in the low memory area.
> Does initramdisk has the similar restriction?

I assume so, as that's what Documentation/arm/Booting says ...

5. Load initramfs.

Existing boot loaders: OPTIONAL
New boot loaders: OPTIONAL

If an initramfs is in use then, as with the dtb, it must be placed in
a region of memory where the kernel decompressor will not overwrite it
while also with the region which will be covered by the kernel's
low-memory mapping.

A safe location is just above the device tree blob which itself will
be loaded just above the 128MiB boundary from the start of RAM as
recommended above.