[PATCH v2 31/34] ARM: mmu32: read TTB value from register

[Sascha Hauer]

On Fri, May 19, 2023 at 08:53:34AM +0200, Ahmad Fatoum wrote:
> On 17.05.23 16:39, Sascha Hauer wrote:
> > On Wed, May 17, 2023 at 03:58:01PM +0200, Ahmad Fatoum wrote:
> >> On 17.05.23 11:03, Sascha Hauer wrote:
> >>> Instead of relying on a variable for the location of the TTB which we
> >>> have to initialize in both PBL and barebox proper, just read the value
> >>> back from the hardware register.
> >>
> >> Why not initialize on first call to get_ttb()?
> > 
> > get_ttb() doesn't have access to endmem which we would need to get the
> > address for the ttb.
> > 
> > Also we have the value in the hardware register, why not use it?
> 
> I meant initialization using the hardware register.

You mean something like:

static uint32_t *ttb;

static inline uint32_t *get_ttb(void)
{
	if (!ttb)
		ttb = (uint32_t *)(get_ttbr() & ~0x3fff);

	return ttb;
}

If yes, I don't know what this is good for. If no, please explain, I
don't seem to understand what you mean.

Sascha

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