Re: [PATCH v2 2/2] ARM: imx: imx8mn-evk: use one common u-boot.dtsi for the evk boards

[Alper Nebi Yasak <alpernebiyasak@gmail.com>]

On 09/06/2022 23:49, Heiko Thiery wrote:
> To have only one place to describe the binman images us the
> imx8mn-u-boot.dtsi. To have support for different DDR firmwares this
> nodes are included dependent on the used DDR config option.
> 
> Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
> Reviewed-by: Fabio Estevam <festevam@gmail.com>
> ---
> v2: sync with current master and fix merge conflict
> 
>  arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi | 125 +-----------------
>  arch/arm/dts/imx8mn-evk-u-boot.dtsi      | 120 +----------------
>  arch/arm/dts/imx8mn-u-boot.dtsi          | 156 +++++++++++++++++++++++

I see most of this is moving existing definitions, but I'm adding
comments in a general sense, partially for future reference.

>  3 files changed, 159 insertions(+), 242 deletions(-)
>  create mode 100644 arch/arm/dts/imx8mn-u-boot.dtsi
> 
> diff --git a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
> index 4d0ecb07d4..3d0e817313 100644
> --- a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
> +++ b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
> @@ -3,11 +3,9 @@
>   * Copyright 2019, 2021 NXP
>   */
>  
> -/ {
> -	binman: binman {
> -		multiple-images;
> -	};
> +#include "imx8mn-u-boot.dtsi"
>  
> +/ {
>  	wdt-reboot {
>  		compatible = "wdt-reboot";
>  		wdt = <&wdog1>;
> @@ -143,122 +141,3 @@
> [...]
> diff --git a/arch/arm/dts/imx8mn-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
> index d1427941eb..339c3dd681 100644
> --- a/arch/arm/dts/imx8mn-evk-u-boot.dtsi
> +++ b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
> @@ -3,6 +3,7 @@
>   * Copyright 2019 NXP
>   */
>  
> +#include "imx8mn-u-boot.dtsi"
>  #include "imx8mn-ddr4-evk-u-boot.dtsi"

"imx8mn-ddr4-evk-u-boot.dtsi" already includes "imx8mn-u-boot.dtsi". I
think it should only be included once.

I don't know why these are structured this way, but I think common parts
of the two boards should've been in a "imx8mn-evk-common-u-boot.dtsi" or
something which the board -u-boot.dtsi files would include.

>  
>  &i2c1 {
> @@ -24,122 +25,3 @@
> [...]
> diff --git a/arch/arm/dts/imx8mn-u-boot.dtsi b/arch/arm/dts/imx8mn-u-boot.dtsi
> new file mode 100644
> index 0000000000..7b591085a0
> --- /dev/null
> +++ b/arch/arm/dts/imx8mn-u-boot.dtsi
> @@ -0,0 +1,156 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2019 NXP
> + */
> +
> +/ {
> +	binman: binman {
> +		multiple-images;
> +	};
> +};
> +
> +&binman {
> +	 u_boot_spl_ddr: u-boot-spl-ddr {
> +		filename = "u-boot-spl-ddr.bin";
> +		pad-byte = <0xff>;
> +		align-size = <4>;
> +		align = <4>;
> +
> +		u-boot-spl {
> +			align-end = <4>;
> +		};

Maybe it's better to add an empty 'ddr-fw' section here, and populate
that below.

> +	};
> +
> +	spl {
> +		filename = "spl.bin";
> +
> +		mkimage {
> +			args = "-n spl/u-boot-spl.cfgout -T imx8mimage -e 0x912000";
> +
> +			blob {
> +				filename = "u-boot-spl-ddr.bin";
> +			};
> +		};
> +	};
> +
> +	itb {
> +		filename = "u-boot.itb";
> +
> +		fit {
> +			description = "Configuration to load ATF before U-Boot";
> +			#address-cells = <1>;
> +			fit,external-offset = <CONFIG_FIT_EXTERNAL_OFFSET>;
> +
> +			images {
> +				uboot {
> +					description = "U-Boot (64-bit)";
> +					type = "standalone";
> +					arch = "arm64";
> +					compression = "none";
> +					load = <CONFIG_SYS_TEXT_BASE>;
> +
> +					uboot_blob: blob-ext {
> +						filename = "u-boot-nodtb.bin";
> +					};
> +				};
> +
> +				atf {
> +					description = "ARM Trusted Firmware";
> +					type = "firmware";
> +					arch = "arm64";
> +					compression = "none";
> +					load = <0x960000>;
> +					entry = <0x960000>;
> +
> +					atf_blob: blob-ext {
> +						filename = "bl31.bin";
> +					};
> +				};
> +
> +				fdt {
> +					description = "NAME";
> +					type = "flat_dt";
> +					compression = "none";
> +
> +					uboot_fdt_blob: blob-ext {
> +						filename = "u-boot.dtb";
> +					};
> +				};

These three 'blob-ext's would normally be 'u-boot-nodtb', 'atf-bl31',
and 'u-boot-dtb' entries respectively.

> +			};
> +
> +			configurations {
> +				default = "conf";
> +
> +				conf {
> +					description = "NAME";

This 'NAME' (and the fdt one) shows up in `mkimage -l u-boot.itb`
output. Perhaps they were originally copied from a @fdt-SEQ version
(which replaces it with the actual dtb filename).

> +					firmware = "uboot";
> +					loadables = "atf";
> +					fdt = "fdt";
> +				};
> +			};
> +		};
> +	};
> +
> +	imx-boot {
> +		filename = "flash.bin";
> +		pad-byte = <0x00>;
> +
> +		spl: blob-ext@1 {
> +			offset = <0x0>;
> +			filename = "spl.bin";
> +		};
> +
> +		uboot: blob-ext@2 {
> +			offset = <0x58000>;
> +			filename = "u-boot.itb";
> +		};
> +	};

I dislike having 'blob-ext's as names, they should be descriptive.
'imx8mm-u-boot.dtsi' has these labels as node names which is slightly
better.

> +};
> +
> +#ifdef CONFIG_IMX8M_DDR4
> +&u_boot_spl_ddr {
> +	blob_1: blob-ext@1 {
> +		filename = "ddr4_imem_1d_201810.bin";
> +		size = <0x8000>;
> +	};
> +
> +	blob_2: blob-ext@2 {
> +		filename = "ddr4_dmem_1d_201810.bin";
> +		size = <0x4000>;
> +	};
> +
> +	blob_3: blob-ext@3 {
> +		filename = "ddr4_imem_2d_201810.bin";
> +		size = <0x8000>;
> +	};
> +
> +	blob_4: blob-ext@4 {
> +		filename = "ddr4_dmem_2d_201810.bin";
> +		size = <0x4000>;
> +	};
> +};
> +#elif CONFIG_IMX8M_LPDDR4
> +&u_boot_spl_ddr {
> +	blob_1: blob-ext@1 {
> +		filename = "lpddr4_pmu_train_1d_imem.bin";
> +		size = <0x8000>;
> +	};
> +
> +	blob_2: blob-ext@2 {
> +		filename = "lpddr4_pmu_train_1d_dmem.bin";
> +		size = <0x4000>;
> +	};
> +
> +	blob_3: blob-ext@3 {
> +		filename = "lpddr4_pmu_train_2d_imem.bin";
> +		size = <0x8000>;
> +	};
> +
> +	blob_4: blob-ext@4 {
> +		filename = "lpddr4_pmu_train_2d_dmem.bin";
> +		size = <0x4000>;
> +	};
> +};

These conflict a bit with one of Peng's series which changes the names
and removes the size for these blobs, see [1] [2].

[1] arm: dts: imx8m: update binman ddr firmware node name
https://lore.kernel.org/u-boot/20220603071715.15212-4-peng.fan@oss.nxp.com/

[2] arm: dts: imx8m: shrink ddr firmware size to actual file size
https://lore.kernel.org/u-boot/20220603071715.15212-7-peng.fan@oss.nxp.com/

> +#else
> +	#error "no valid ddr config selected"

There's also IMX8M_DDR3L, see imx8mn-bsh-smm-s2-u-boot-common.dtsi

> +#endif