Hi,
On 22-01-15 22:03, Tom Rini wrote:
On Thu, Jan 22, 2015 at 08:10:06PM +0100, Hans de Goede wrote:
Hi,
On 22-01-15 17:20, Tom Rini wrote:
On Wed, Jan 21, 2015 at 09:03:25PM +0100, Hans de Goede wrote:
On some SoCs / ARMv7 CPU cores we need to do some setup before enabling the
icache, etc. Add a soc_init hook with a weak default which just calls
cpu_init_cp15.
This way different implementations can be provided to do some extra work
before or after cpu_init_cp15, or completely replacing cpu_init_cp15.
Signed-off-by: Hans de Goede <hdego...@redhat.com>
---
arch/arm/cpu/armv7/start.S | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index fdc05b9..9882b20 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -64,7 +64,7 @@ reset:
/* the mask ROM code should have PLL and others stable */
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
- bl cpu_init_cp15
+ bl soc_init
bl cpu_init_crit
#endif
I like the direction here. And I want to make sure I get the sunxi
direction right here too (as I agree with the need / desire for boot0 +
U-Boot to be a valid combination). I think we can take this a step
farther. cpu_init_crit (on armv7) is basically a call to s_init().
For am33xx (and I bet but need to do and test omap3+) we can, with
Simon's patch to let us move stack to DDR a tiny bit later, in the SPL
case make s_init empty, which just leaves us with (with your patch)
soc_init. Is there some way we can put all of this together in a
function?
You mean essentially call s_init here and have s_init call cpu_init_cp15
I guess we could do that, but it would require auditing all existing armv7
users of s_init. This may require me to rethink how / when I do timer &
gpio init etc. for u-boot.bin on sunxi, but that should not be a (big)
problem.
Basically. From my first pass audit of s_init, it's either empty
(Kona), sunxi, or omap/etc so I get to deal with it. And the default
soc_init would just be the call to cpu_init_cp15 as you have it and we
drop the lowlevel_init hurdles.
Ok, so what you're suggesting is a patch which:
1) Changes:
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_cp15
bl cpu_init_crit
#endif
Into:
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl lowlevel_init
#endif
Which will setup the stack and then call the s_init C function
2) Adds a weak default s_init which calls cpu_init_cp15
3) Patch all existing s_init functions to call cpu_init_cp15
before doing anything else.
And then in follow up patches we can:
4) Drop cpu_init_crit
5) Cleanup some s_init functions (this will be left to the individual
SoC maintainers)
I think that is a good idea, Albert what do you think about this ?
Regards,
Hans
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