Re: [PATCH v2 2/2] board: phycore_imx8mm: add 1 and 4GB RAM timings

Yannic Moog <[email protected]>
Newsgroups gmane.comp.boot-loaders.u-boot
Message-ID <[email protected]> 
On Thu, 2026-07-09 at 16:34 +0200, INgo Rah wrote:
> The Phytec Tauri L is sold with multiple memory configurations beyond the
> base 2 GB variant. To support these alternative capacities seamlessly,
> read the physical memory size directly from the EEPROM of the underlying
> phyCORE module and apply the appropriate DDR timing parameters at runtime.
> 
> Alternatively, a fixed memory configuration can still be enforced via a
> dedicated Kconfig option if dynamic detection is not desired.
> 
> Note that while U-Boot correctly discovers the full physical memory bank,
> the device tree excludes the memory beyond 3 GB  (below the 4 GB boundary).
> This ensures that U-Boot allocations and early EFI staging buffers remain
> safe from 32-bit interconnect DMA limitations inherent to some i.MX8MM
> IP blocks.
> 
> Signed-off-by: INgo Rah <[email protected]>
> Reviewed-by: Gregor Herburger <[email protected]>
> Reviewed-by: Benedikt Spranger <[email protected]>

Reviewed-by: Yannic Moog <[email protected]>
Tested-by: Yannic Moog <[email protected]>

> ---
>  arch/arm/dts/imx8mm-phygate-tauri-l-u-boot.dtsi | 23 +++++++++
>  board/phytec/phycore_imx8mm/Kconfig             | 65 +++++++++++++++++++++++++
>  board/phytec/phycore_imx8mm/phycore-imx8mm.c    | 18 +++++++
>  board/phytec/phycore_imx8mm/spl.c               | 56 ++++++++++++++++++++-
>  configs/imx8mm-phygate-tauri-l_defconfig        |  1 +
>  include/configs/phycore_imx8mm.h                |  5 +-
>  6 files changed, 165 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/dts/imx8mm-phygate-tauri-l-u-boot.dtsi b/arch/arm/dts/imx8mm-phygate-tauri-
> l-u-boot.dtsi
> index 26361780c01..452bf3d41f1 100644
> --- a/arch/arm/dts/imx8mm-phygate-tauri-l-u-boot.dtsi
> +++ b/arch/arm/dts/imx8mm-phygate-tauri-l-u-boot.dtsi
> @@ -6,6 +6,21 @@
>  #include "imx8mm-u-boot.dtsi"
>  
>  / {
> +	reserved-memory {
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		ranges;
> +
> +		/*
> +		 * Limit memory usage below the 4 GB (32-bit) boundary.
> +		 * The i.MX8MM DMA and peripherals cannot access >32-bit
> +		 * addresses. This prevents allocation failures in UEFI mode.
> +		 */
> +		u_boot_sdma_shield: sdma-shield@100000000 {
> +			reg = <0x1 0x00000000 0x0 0x40000000>;
> +		};
> +	};
> +
>  	wdt-reboot {
>  		compatible = "wdt-reboot";
>  		wdt = <&wdog1>;
> @@ -29,6 +44,10 @@
>  	};
>  };
>  
> +&pinctrl_i2c1 {
> +	bootph-pre-ram;
> +};
> +
>  &pinctrl_uart3 {
>  	bootph-pre-ram;
>  };
> @@ -73,6 +92,10 @@
>  	bootph-pre-ram;
>  };
>  
> +&i2c1 {
> +	bootph-pre-ram;
> +};
> +
>  &usdhc2 {
>  	bootph-pre-ram;
>  };
> diff --git a/board/phytec/phycore_imx8mm/Kconfig b/board/phytec/phycore_imx8mm/Kconfig
> index 06449128ba8..609c11580ce 100644
> --- a/board/phytec/phycore_imx8mm/Kconfig
> +++ b/board/phytec/phycore_imx8mm/Kconfig
> @@ -12,5 +12,70 @@ config SYS_CONFIG_NAME
>  config IMX_CONFIG
>  	default "board/phytec/phycore_imx8mm/imximage-8mm-sd.cfg"
>  
> +config PHYCORE_IMX8MM_RAM_SIZE_FIX
> +	bool "Set phyCORE-i.MX8MM RAM size fix instead of detecting"
> +	default false
> +	help
> +	  RAM size is automatic being detected with the help of
> +	  the EEPROM introspection data. Set RAM size to a fix value
> +	  instead.
> +
> +choice
> +	prompt "phyCORE-i.MX8MM RAM size"
> +	depends on PHYCORE_IMX8MM_RAM_SIZE_FIX
> +	default PHYCORE_IMX8MM_RAM_SIZE_2GB
> +	help
> +	  Select a fixed RAM size instead of EEPROM introspection
> +	  data.
> +
> +config PHYCORE_IMX8MM_RAM_SIZE_1GB
> +	bool "1GB RAM"
> +	help
> +	  Set RAM size fix to 1GB for phyCORE-i.MX8MM
> +	  instead of runtime detection from EEPROM.
> +
> +config PHYCORE_IMX8MM_RAM_SIZE_2GB
> +	bool "2GB RAM"
> +	help
> +	  Set RAM size fix to 2GB for phyCORE-i.MX8MM
> +	  instead of runtime detection from EEPROM.
> +
> +config PHYCORE_IMX8MM_RAM_SIZE_4GB
> +	bool "4GB RAM"
> +	help
> +	  Set RAM size fix to 4GB for phyCORE-i.MX8MM
> +	  instead of runtime detection from EEPROM.
> +
> +endchoice
> +
> +config PHYCORE_IMX8MM_RAM_STATIC_SOM_REV
> +	bool "Set static phyCORE-i.MX8MM SoM revision for RAM timing setup"
> +	default false
> +	help
> +	  phyCORE-i.MX8MM SoM revision 7 uses a updated set of optimized
> +	  RAM timings compared to revision 6 and older. Set the SoM
> +	  revision during compile time instead of being detected.
> +
> +choice
> +	prompt "phyCORE-i.MX8MM RAM timing SoM revision static config"
> +	depends on PHYCORE_IMX8MM_RAM_STATIC_SOM_REV
> +	default PHYCORE_IMX8MM_USE_SOM_REV_7
> +	help
> +	  Use a fixed revision setting instead of runtime
> +	  auto detection.
> +
> +config PHYCORE_IMX8MM_USE_SOM_REV_6
> +	bool "RAM Timings for SoM Revisions 6 and older"
> +	help
> +	  Use optimized RAM Timings for phyCORE-i.MX8MM SoM Revisions 6
> +	  and older instead of autodetecting.
> +
> +config PHYCORE_IMX8MM_USE_SOM_REV_7
> +	bool "RAM Timings for SoM Revision 7"
> +	help
> +	  Use optimized RAM Timings for phyCORE-i.MX8MM SoM Revision 7
> +	  instead of autodetecting.
> +endchoice
> +
>  source "board/phytec/common/Kconfig"
>  endif
> diff --git a/board/phytec/phycore_imx8mm/phycore-imx8mm.c b/board/phytec/phycore_imx8mm/phycore-
> imx8mm.c
> index 9f6a4ec704d..25e51dce739 100644
> --- a/board/phytec/phycore_imx8mm/phycore-imx8mm.c
> +++ b/board/phytec/phycore_imx8mm/phycore-imx8mm.c
> @@ -9,6 +9,7 @@
>  #include <asm/mach-imx/boot_mode.h>
>  #include <env.h>
>  #include <miiphy.h>
> +#include <init.h>
>  
>  static int setup_fec(void)
>  {
> @@ -50,3 +51,20 @@ int board_late_init(void)
>  
>  	return 0;
>  }
> +
> +int board_phys_sdram_size(phys_size_t *size)
> +{
> +	if (!size)
> +		return -EINVAL;
> +
> +	/*
> +	 * check various RAM sizes (1, 2 and 4 GB) otherwise
> +	 * return the default of 2GB
> +	 */
> +	*size = get_ram_size((void *)PHYS_SDRAM,
> +			     (long)PHYS_SDRAM_SIZE + PHYS_SDRAM_2_SIZE);
> +	if (*size == 0)
> +		*size = SZ_2G;
> +
> +	return 0;
> +}
> diff --git a/board/phytec/phycore_imx8mm/spl.c b/board/phytec/phycore_imx8mm/spl.c
> index e688793bc74..a3879881eb7 100644
> --- a/board/phytec/phycore_imx8mm/spl.c
> +++ b/board/phytec/phycore_imx8mm/spl.c
> @@ -16,11 +16,19 @@
>  #include <log.h>
>  #include <spl.h>
>  
> +#include "lpddr4_timing.h"
>  #include "../common/imx8m_som_detection.h"
>  
>  #define EEPROM_ADDR		0x51
>  #define EEPROM_ADDR_FALLBACK	0x59
>  
> +enum phytec_imx8mm_ddr_eeprom_code {
> +	INVALID = PHYTEC_EEPROM_INVAL,
> +	PHYTEC_IMX8MM_DDR_1GB = 1,
> +	PHYTEC_IMX8MM_DDR_2GB = 3,
> +	PHYTEC_IMX8MM_DDR_4GB = 5,
> +};
> +
>  int spl_board_boot_device(enum boot_device boot_dev_spl)
>  {
>  	switch (boot_dev_spl) {
> @@ -42,17 +50,63 @@ int spl_board_boot_device(enum boot_device boot_dev_spl)
>  static void spl_dram_init(void)
>  {
>  	int ret;
> +	enum phytec_imx8mm_ddr_eeprom_code size = PHYTEC_EEPROM_INVAL;
> +	u8 rev = PHYTEC_EEPROM_INVAL;
>  
>  	ret = phytec_eeprom_data_setup_fallback(NULL, 0, EEPROM_ADDR,
>  			EEPROM_ADDR_FALLBACK);
> -	if (ret)
> +	if (ret && !IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_SIZE_FIX))
>  		goto out;
>  
>  	ret = phytec_imx8m_detect(NULL);
>  	if (!ret)
>  		phytec_print_som_info(NULL);
>  
> +	if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_SIZE_FIX)) {
> +		if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_SIZE_1GB))
> +			size = PHYTEC_IMX8MM_DDR_1GB;
> +		else if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_SIZE_2GB))
> +			size = PHYTEC_IMX8MM_DDR_2GB;
> +		else if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_SIZE_4GB))
> +			size = PHYTEC_IMX8MM_DDR_4GB;
> +	} else {
> +		size = phytec_get_imx8m_ddr_size(NULL);
> +	}
> +
> +	if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_RAM_STATIC_SOM_REV)) {
> +		if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_USE_SOM_REV_6))
> +			rev = 6;
> +		else if (IS_ENABLED(CONFIG_PHYCORE_IMX8MM_USE_SOM_REV_7))
> +			rev = 7;
> +	} else {
> +		rev = phytec_get_rev(NULL);
> +	}
> +
> +	if (rev >= 7 || rev == PHYTEC_EEPROM_INVAL) {
> +		debug("%s: Using rev7 RAM timings.\n", __func__);
> +		set_dram_timings_rev7();
> +	} else {
> +		debug("%s: Using rev6 RAM timings.\n", __func__);
> +	}
> +
> +	switch (size) {
> +	case PHYTEC_IMX8MM_DDR_1GB:
> +		set_dram_timings_1gb();
> +		break;
> +	case PHYTEC_IMX8MM_DDR_2GB:
> +		break;
> +	case PHYTEC_IMX8MM_DDR_4GB:
> +		set_dram_timings_4gb();
> +		break;
> +	default:
> +		goto out;
> +	}
> +	ddr_init(&dram_timing);
> +
> +	return;
>  out:
> +	puts("Could not detect correct RAM size. Fall back to default.\n");
> +	set_dram_timings_rev7();
>  	ddr_init(&dram_timing);
>  }
>  
> diff --git a/configs/imx8mm-phygate-tauri-l_defconfig b/configs/imx8mm-phygate-tauri-l_defconfig
> index 9dc7fe21820..3ae92ff09f6 100644
> --- a/configs/imx8mm-phygate-tauri-l_defconfig
> +++ b/configs/imx8mm-phygate-tauri-l_defconfig
> @@ -4,6 +4,7 @@ CONFIG_TEXT_BASE=0x40200000
>  CONFIG_SYS_MALLOC_LEN=0x2000000
>  CONFIG_SPL_GPIO=y
>  CONFIG_SPL_LIBCOMMON_SUPPORT=y
> +CONFIG_PHYTEC_SOM_DETECTION=y
>  CONFIG_ENV_SIZE=0x10000
>  CONFIG_ENV_OFFSET=0x3C0000
>  CONFIG_DM_GPIO=y
> diff --git a/include/configs/phycore_imx8mm.h b/include/configs/phycore_imx8mm.h
> index 20e2ab832ee..d4571cc6f39 100644
> --- a/include/configs/phycore_imx8mm.h
> +++ b/include/configs/phycore_imx8mm.h
> @@ -28,6 +28,7 @@
>  #define CFG_SYS_SDRAM_BASE		0x40000000
>  
>  #define PHYS_SDRAM			0x40000000
> -#define PHYS_SDRAM_SIZE                 SZ_2G /* 2GB DDR */
> -
> +#define PHYS_SDRAM_SIZE                 (SZ_2G + SZ_1G) /* 3GB */
> +#define PHYS_SDRAM_2                    0x100000000
> +#define PHYS_SDRAM_2_SIZE                SZ_1G /* 4GB DDR */
>  #endif /* __PHYCORE_IMX8MM_H */
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