[RFC 2/3] MIPS: add the initial support for lowlevel init

[Antony Pavlov]

This commit introduce the initial support for
machine specific lowlevel initialization
(e.g. RAM controller or cache memory).

To return from mach_init_lowlevel() it uses
explicit mach_init_lowlevel_return label.
This saves ra register for using inside mach_init_lowlevel()

Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
---
 arch/mips/boot/start.S |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/mips/boot/start.S b/arch/mips/boot/start.S
index 6bf5baa..6db104b 100644
--- a/arch/mips/boot/start.S
+++ b/arch/mips/boot/start.S
@@ -74,6 +74,14 @@ __start:
 	and	k0, k1
 	mtc0	k0, CP0_STATUS
 
+#ifdef CONFIG_MACH_DO_LOWLEVEL_INIT
+	b	mach_init_lowlevel
+	 nop
+
+mach_init_lowlevel_return:
+EXPORT(mach_init_lowlevel_return)
+#endif
+
 	/* copy barebox to link location */
 	ADR	a0, _start, t1	/* a0 <- pc-relative position of _start */
 
-- 
1.7.10