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

Stefano Babic
2014-03-30T16:30:13Z

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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