Hi,
On 26-01-15 09:09, Albert ARIBAUD wrote:
Hello Tom,
On Thu, 22 Jan 2015 11:20:58 -0500, Tom Rini <tr...@ti.com> 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.
I don't like all of it, specifically the double call, to cpu_init_cp15
then soc_init, for two reasons:
0) soc_init might touch cp15, but it's hidden in the name whereas it is
shown in cpu_init_cp15. Either both names should explicitly say they
are touching cp15, or both should not.
1) we cannot tell if cpu_init_cp15 should always happen before
soc_init. Having a single call to soc_init, with the understanding
that it will handle the cpu_init_cp15 call itself, makes it
possible for soc_init yo decide whether it wants to call
cpu_init_cp15 first, last or at all.
There is no double call, the call to cpu_init_cp15 is being replaced with
a call to soc_init, which then can call cpu_init_cp15 at any time it likes.
Also see the discussion further in the thread about replacing soc_init
with a call to lowlevel_init which then call s_init which may then call
cpu_init_cp15 at a convenient time, the advantage of this approach is that
the soc / board specific code can be written in C rather then in asm.
Regards,
Hans
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