[U-Boot] [PATCH 1/1] imx-common: cpu: add fdt_file environment variable

[Stefano Babic <sbabic@denx.de>]

Hi Troy,

On 29/03/2014 23:34, Troy Kisky wrote:
> This removes one block in the move toward 1 u-boot
> for both a mx6q (quad) and mx6dl (duallite) processor.
> 
> Now fdt_file hardcoded value can be removed.
> 
> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
> ---

I have a general problem with this implementation. I am ok if, as you
proposed some times ago, there is a general rule for the "default" dtb
file in the CONFIG_EXTRA_ENV.

However, you are binding in code naming conventions. In U-boot, it must
be allowed to set the environment as the user wants, and this must be
not overwritten by such an internal code.

I mean: a board user, if he wants, should be allowed to do something as

	setenv fdt_file my_preferred_dtb_name.dtb

and this must work when the file is loaded from storage - this is not
possible if the rule chosen from user is overwritten by code.

This makes the environment useless and generates headaches for a lot of
users. They will ask themselves why the wrong file is taken when they
tried in any way to set it differently...

>  arch/arm/imx-common/cpu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  arch/arm/lib/board.c      |  7 +++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/arch/arm/imx-common/cpu.c b/arch/arm/imx-common/cpu.c
> index a77c4de..5d48011 100644
> --- a/arch/arm/imx-common/cpu.c
> +++ b/arch/arm/imx-common/cpu.c
> @@ -180,3 +180,47 @@ void arch_preboot_os(void)
>  	ipuv3_fb_shutdown();
>  }
>  #endif
> +
> +const char *get_dtb_prefix(u32 imxtype)
> +{
> +	switch (imxtype) {
> +	case MXC_CPU_MX6Q:
> +	case MXC_CPU_MX6D:
> +		return "imx6q";		/* Quad/Dual-core version of the mx6 */
> +	case MXC_CPU_MX6DL:
> +	case MXC_CPU_MX6SOLO:
> +		return "imx6dl";	/* Dual Lite/Solo version of the mx6 */
> +	case MXC_CPU_MX6SL:
> +		return "imx6sl";	/* Solo-Lite version of the mx6 */
> +	case MXC_CPU_MX51:
> +		return "imx51";
> +	case MXC_CPU_MX53:
> +		return "imx53";
> +	}
> +	return "??";
> +}
> +
> +int cpu_late_init(void)
> +{
> +	char buf[128];
> +	const char *board;
> +	u32 imxtype = (get_cpu_rev() >> 12) & 0xff;
> +
> +	if (getenv("fdt_file"))
> +		return 0;
> +	board = getenv("board");
> +	if (!board) {
> +		board = CONFIG_SYS_BOARD;
> +		if ((board[0] == 'm') && (board[1] == 'x')) {
> +			if (board[2] == '6') {
> +				board += 3;
> +			} else if (board[2] == '5') {
> +				if ((board[3] == '1') || (board[3] == '3'))
> +					board += 4;
> +			}
> +		}
> +	}
> +	sprintf(buf, "%s-%s.dtb", get_dtb_prefix(imxtype), board);
> +	setenv("fdt_file", buf);
> +	return 0;
> +}
> diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
> index e9a7708..61cee98 100644
> --- a/arch/arm/lib/board.c
> +++ b/arch/arm/lib/board.c
> @@ -496,6 +496,11 @@ static void display_fdt_model(const void *blob)
>  }
>  #endif
>  
> +int __weak cpu_late_init(void)
> +{
> +	return 0;
> +}
> +
>  /************************************************************************
>   *
>   * This is the next part if the initialization sequence: we are now
> @@ -649,6 +654,8 @@ void board_init_r(gd_t *id, ulong dest_addr)
>  	board_late_init();
>  #endif
>  
> +	cpu_late_init();
> +
>  #ifdef CONFIG_BITBANGMII
>  	bb_miiphy_init();
>  #endif
> 

Best regards,
Stefano Babic

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