mips: Add CONFIG_MIPS_MACH_EARLY_INIT for very early mach init code

This patch adds the optional call to mips_mach_early_init() to start.S
at a very early stage. Its disabled per default. It can be used for
very early machine / platform specific init code.  Its called very
early and at this stage the PC is allowed to differ from the linking
address (CONFIG_TEXT_BASE) as no absolute jump has been performed until
this call.

It will be used by thje Octeon platform.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index eb00ee71bc28981f05b9ec834d1c3905a130c871..652e6a993e842a00732cd29c8015df688134c704 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -270,6 +270,15 @@ config MIPS_CACHE_INDEX_BASE
          Normally this is CKSEG0. If the MIPS system needs to move this block
          to some SRAM or ScratchPad RAM, adapt this option accordingly.
 
+config MIPS_MACH_EARLY_INIT
+       bool "Enable mach specific very early init code"
+       help
+         Use this to enable the call to mips_mach_early_init() very early
+         from start.S. This function can be used e.g. to do some very early
+         CPU / SoC intitialization or image copying. Its called very early
+         and at this stage the PC might not match the linking address
+         (CONFIG_TEXT_BASE) - no absolute jump done until this call.
+
 config MIPS_CACHE_SETUP
        bool "Allow generic start code to initialize and setup caches"
        default n if SKIP_LOWLEVEL_INIT

diff --git a/arch/mips/cpu/start.S b/arch/mips/cpu/start.S
index e22771715c1a555d6cf23ecdee13cb2bb43e456b..d0c412236dd8a7c8d0b2630cc18c2cf4a46b05c5 100644 (file)
--- a/arch/mips/cpu/start.S
+++ b/arch/mips/cpu/start.S
@@ -236,6 +236,11 @@ wr_done:
 # endif
 #endif
 
+#ifdef CONFIG_MIPS_MACH_EARLY_INIT
+       bal     mips_mach_early_init
+        nop
+#endif
+
 #ifdef CONFIG_MIPS_CACHE_SETUP
        /* Initialize caches... */
        PTR_LA  t9, mips_cache_reset