[U-Boot] [PATCH 4/8] orion5x: Allow SDRAM initialization to be omitted
Albert ARIBAUD
albert.aribaud at free.fr
Sat Jan 29 08:36:03 CET 2011
Le 29/01/2011 02:00, Michael Spang a écrit :
> For the TS-7800, the FPGA contains a bootloader which handles
> the SDRAM initialization and loads a bootloader from RAM. We
> should not try to initialize RAM again while running from it.
>
> Signed-off-by: Michael Spang<mspang at csclub.uwaterloo.ca>
> ---
> arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S b/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S
> index 0523bd4..37d7d14 100644
> --- a/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S
> +++ b/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S
> @@ -86,6 +86,8 @@
>
> lowlevel_init:
>
> +#ifndef CONFIG_SKIP_SDRAM_INIT
> +
> /* Use 'r4 as the base for internal register accesses */
> ldr r4, =ORION5X_REGS_PHY_BASE
>
> @@ -289,5 +291,7 @@ lowlevel_init:
> orr r2, r2, r6
> str r2, [r3, #0x484]
>
> +#endif
> +
> /* Return to U-boot via saved link register */
> mov pc, lr
That's basically making lowlevel_init empty, so I would prefer that you
put #ifdef/#endif around the call to lowlevel_init in start.S and modify
the orion5x Makefile to include lowlevel_init.S only if
CONFIG_SKIP_DRAM_INIT is not defined.
(come to think of it, CONFIG_SKIP_LOWLEVEL_INIT is a bit of a misnomer
since it actually skips not only lowlevelinit but also cpu_init_crit.
Possibly one could even go as far as renaming CONFIG_SKIP_LOWLEVEL_INIT
to CONFIG_SKIP_CPU_INIT_CRIT, and then reuse CONFIG_SKIP_LOWLEVEL_INIT
for lowlevel_init; but that can be a separate patch, with a nifty doc
update.)
Amicalement,
--
Albert.
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