[U-Boot] Do we really need CONFIG_ARCH_CPU_INIT ?

Fabio Estevam festevam at gmail.com
Thu Mar 1 14:23:10 CET 2012


Hi,

Currently CONFIG_ARCH_CPU_INIT is used to select arch_cpu_init() function.

arch_cpu_init() does CPU level initialization, so why do we need to
include CONFIG_ARCH_CPU_INIT in the include/configs/boardXYZ files,
which are board related files ?

For example:

Let's say boards X, Y and Z are based on SoC S:

1. If processor S has a arch_cpu_init() defined, then it means that
X,Y,Z need the code from arch_cpu_init() and then we need to define
CONFIG_ARCH_CPU_INIT for each of these boards (actually all the boards
based on this processor would need CONFIG_ARCH_CPU_INIT)

2. If not all boards need the code inside arch_cpu_init() for
processor S, then it means that this code is not really CPU specific
and then it should be moved to board code.

I was thinking in doing the following:

--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -224,10 +224,15 @@ void __dram_init_banksize(void)
 void dram_init_banksize(void)
        __attribute__((weak, alias("__dram_init_banksize")));

+int __arch_cpu_init(void)
+{
+       return 0;
+}
+int arch_cpu_init(void)
+       __attribute__((weak, alias("__arch_cpu_init")));
+
 init_fnc_t *init_sequence[] = {
-#if defined(CONFIG_ARCH_CPU_INIT)
        arch_cpu_init,          /* basic arch cpu dependent setup */
-#endif
 #if defined(CONFIG_BOARD_EARLY_INIT_F)
        board_early_init_f,
 #endif

,so that CONFIG_ARCH_CPU_INIT is not needed anymore.

Before I go further in this route to remove CONFIG_ARCH_CPU_INIT from
other places, I would like to know if this makes sense.

Thanks,

Fabio Estevam


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