[PATCH u-boot v2019.04-aspeed-openbmc v2] aspeed: add CONFIG_ASPEED_ENABLE_BACKDOORS

[Zev Weiss]

On Fri, Apr 15, 2022 at 01:11:09AM PDT, Ryan Chen wrote:
>Hello,
>	Thanks your response.
>	And yes, I prefer apply patch without any config to disable it.
>
>Ryan
>

After thinking about this a bit more, I remembered that Ian Woloschin 
(CCed) had mentioned at some point that the systems he works with do in 
fact use the AST2500's built-in Super-IO, and hence would presumably be 
broken by a patch that unconditionally disabled that.  And in contrast, 
the ASRock boards I've been working with require the AST2500 Super-IO to 
be disabled for the host to boot properly, so it seems like we'll need  
*some* minimal amount of configurability to support at least those two 
classes of systems (i.e. a Kconfig boolean that determines whether the 
Super-IO should be enabled or disabled).

I don't know offhand what the interactions between SCU70[20], HICRB[6], 
and HICR5[10] are though, and I don't have any hardware that actually 
uses the AST2500 Super-IO to test with.  Would leaving SCU70[20]=0 to 
enable the Super-IO while leaving HICRB[6]=1 and HICR5[10]=0 work for 
systems like Ian's to enable the Super-IO while keeping everything else 
locked down as much as possible?


Zev