Subject: Re: [PATCH v1 03/13] powerpc/mm/32s: rework mmu_mapin_ram()

From: Jonathan Neuschäfer <[email-masked]>
Date: Tue, 18 Dec 2018 04:05:38 +0100

On Mon, Dec 17, 2018 at 10:29:18AM +0100, Christophe Leroy wrote:
> > With patches 1-3:
> > [    0.000000] setbat(0, c0000000, 00000000, 01000000, 311)
> > [    0.000000] setbat(2, c1000000, 01000000, 00800000, 311)
> > [    0.000000] setbat(4, d0000000, 10000000, 02000000, 791)
> 
> What we see is that BAT0 is not used in the origin. I have always wondered
> the reason, maybe there is something odd behind and BAT0 shall no ne used.
> 
> Could you try and modify find_free_bat() so that it starts at b = 1 instead
> of b = 0 ?

In this case, setbat is called with index 2, 3, and 4, but the Wii still
doesn't boot.

> > According to arch/powerpc/include/asm/book3s/32/hash.h,
> >   - 0x591 = _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | _PAGE_PRESENT
> >   - 0x311 = _PAGE_EXEC | _PAGE_ACCESSED | _PAGE_COHERENT | _PAGE_PRESENT
> >   - 0x791 = _PAGE_RW | _PAGE_EXEC | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | _PAGE_PRESENT
> > 
> 
> Yes, patch 1 added _PAGE_EXEC which explains this 0x200.
> Do you confirm it still works well with only patch 1 ?

Patch 1 alone boots to userspace.

Jonathan