[PATCH 2/2] arm64: Pass RAM boundary and enable-dcache flag to purgatory

Pratyush Anand
2016-11-23T01:46:26Z

Hi Geoff,

On Wednesday 23 November 2016 12:27 AM, Geoff Levand wrote:
> Hi Pratyush,
>
> On 11/21/2016 08:32 PM, Pratyush Anand wrote:
>> When "enable-dcache" is passed to the kexec() command line, kexec-tools
>> passes this information to purgatory, which in turn enables cache during
>> sha-256 verification.
>
> What's the point of this enable-dcache option? Why not just
> always enable the cache if we can?

As I have written in changelog of patch 1/2

"We are supporting only 4K and 64K page sizes. This code will not work if a
hardware is not supporting at least one of these page sizes. Therefore,
D-cache is disabled by default and enabled only when "enable-dcache" is
passed to the kexec()."

Although this is very unlikely that a hardware will support only 16K
page sizes, however it is possible. Therefore, its better to keep it
disabled by default.

~Pratyush