[U-Boot] [PATCH] [ARM] Move machine specific code to board at s3c64xx

[Guennadi Liakhovetski]

On Wed, 22 Oct 2008, Kyungmin Park wrote:

> Move machine specific code to smdk6400.
> Some board use OneNAND instead of NAND.
> 
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> ---
> diff --git a/board/samsung/smdk6400/lowlevel_init.S b/board/samsung/smdk6400/lowlevel_init.S
> index e0119a7..53d9125 100644
> --- a/board/samsung/smdk6400/lowlevel_init.S
> +++ b/board/samsung/smdk6400/lowlevel_init.S
> @@ -104,6 +104,13 @@ lowlevel_init:
>  	bl nand_asm_init
>  #endif
>  
> +	/* Memory subsystem address 0x7e00f120 */
> +	ldr	r0, =ELFIN_MEM_SYS_CFG
> +
> +	/* Xm0CSn2 = NFCON CS0, Xm0CSn3 = NFCON CS1 */
> +	mov	r1, #0xd
> +	str	r1, [r0]
> +

Hm, no, I don't quite agree. In principle, yes, this configuration can be 
considered platform-specific and moving it this way of course works. But:

1. The patch comment is not correct. This code doesn't select between NAND 
   and OneNAND. It selects between (one of) NANDs and SROMs.

2. While at it, we could fix the value being written to the MEM_SYS_CFG 
   register too. Currently it writes 0xd = 

  (1 << 0) - ignored, default 0, so, better set it to 0
| (0 << 1) - set Xm0CSn[2] to OneNANDC CS0 or NFCON CS0
| (1 << 2) - ignored, default 0, so, better set it to 0
| (1 << 3) - set Xm0CSn[3] to SROMC CS3

So, we should just write an 8 in it:

+	mov	r1, #0x8
+	str	r1, [r0]

3. The comment in the code doesn't look right. According to the above it 
   should read

+	/* Xm0CSn[2] = OneNANDC CS0 or NFCON CS0, Xm0CSn[3] = SROMC CS3 */

The only thing that confuses me, is why the author, belonging to the 
manufacturer of the chip, hasn't done this. Maybe the documentation is 
wrong?

I tested it with the "8" - it works. So, once the issues are fixed, you 
get my "Tested-by", although, I guess, you can test it just as well:-)

Thanks
Guennadi

>  	bl	mem_ctrl_asm_init
>  
>  /* Wakeup support. Don't know if it's going to be used, untested. */
> diff --git a/cpu/arm1176/s3c64xx/cpu_init.S b/cpu/arm1176/s3c64xx/cpu_init.S
> index 08bda99..32bb467 100644
> --- a/cpu/arm1176/s3c64xx/cpu_init.S
> +++ b/cpu/arm1176/s3c64xx/cpu_init.S
> @@ -28,13 +28,6 @@
>  
>  	.globl mem_ctrl_asm_init
>  mem_ctrl_asm_init:
> -	/* Memory subsystem address 0x7e00f120 */
> -	ldr	r0, =ELFIN_MEM_SYS_CFG
> -
> -	/* Xm0CSn2 = NFCON CS0, Xm0CSn3 = NFCON CS1 */
> -	mov	r1, #0xd
> -	str	r1, [r0]
> -
>  	/* DMC1 base address 0x7e001000 */
>  	ldr	r0, =ELFIN_DMC1_BASE
>  
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> 

---
Guennadi Liakhovetski, Ph.D.

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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