arm: imx: add iMX7S WaARP7 MBL board definition

This patch adds an OP-TEE port for the i.MX7S WaRP7 for the MBED Linux OS
boot flow.

BootROM -> ATF/BL2
ATF     -> FIP {u-boot, OPTEE}
OPTEE   -> {populates DTB overlay}
u-boot  -> FIT {DTB, Kernel, initramfs}
           Merges DTB and OPTEE DTB-overlay
Linux

The current warp7 port looks like
BootROM -> u-boot
u-boot  -> Load {Kernel, OPTEE, DTB}
OPTEE
Linux

In order to support the ATF bootflow a new port of OP-TEE with slightly
tweaked parameters is added here.

CFG_NS_ENTRY_ADDR = 0x87800000 is the entry point of u-boot
CFG_DT_OVERLAY = y adds DTB overlay fragments to the passed DTB

make PLATFORM=imx-mx7swarp7_mbl

Signed-off-by: Bryan O'Donoghue <[email protected]>
Reviewed-by: Peng Fan <[email protected]>

README.md

@@ -75,6 +75,7 @@ The **Maintained?** column shows:
 | [FSL i.MX6 UltraLite EVK Board](http://www.freescale.com/products/arm-processors/i.mx-applications-processors-based-on-arm-cores/i.mx-6-processors/i.mx6qp/i.mx6ultralite-evaluation-kit:MCIMX6UL-EVK) |`PLATFORM=imx-mx6ulevk`| Yes | ![Actively Maintained](documentation/images/green.svg) |
 | [NXP i.MX7Dual SabreSD Board](http://www.nxp.com/products/software-and-tools/hardware-development-tools/sabre-development-system/sabre-board-for-smart-devices-based-on-the-i.mx-7dual-applications-processors:MCIMX7SABRE) |`PLATFORM=imx-mx7dsabresd`| Yes | ![Actively Maintained](documentation/images/green.svg) |
 | [NXP i.MX7Solo WaRP7 Board](http://www.nxp.com/products/developer-resources/reference-designs/warp7-next-generation-iot-and-wearable-development-platform:WARP7) |`PLATFORM=imx-mx7swarp7`| Yes | ![Actively Maintained](documentation/images/green.svg) |
+| [NXP i.MX7Solo WaRP7 Board - Mbed Linux OS](https://os.mbed.com/platforms/WaRP7) |`PLATFORM=imx-mx7swarp7_mbl`| Yes | ![Actively Maintained](documentation/images/green.svg) |
 | [NXP i.MX8MQEVK Board](https://www.nxp.com/support/developer-resources/run-time-software/i.mx-developer-resources/evaluation-kit-for-the-i.mx-8m-applications-processor:MCIMX8M-EVK) |`PLATFORM=imx-imx8mqevk`| Yes | ![Actively Maintained](documentation/images/green.svg) |
 | [NXP i.MX8MMEVK Board](https://www.nxp.com/products/processors-and-microcontrollers/arm-based-processors-and-mcus/i.mx-applications-processors/i.mx-8-processors/i.mx-8m-mini-family-arm-cortex-a53-cortex-m4-audio-voice-video:i.MX8MMINI?lang=en&lang_cd=en&) |`PLATFORM=imx-imx8mmevk`| Yes | ![Actively Maintained](documentation/images/green.svg) |
 | [ARM Foundation FVP](https://developer.arm.com/products/system-design/fixed-virtual-platforms) |`PLATFORM=vexpress-fvp`| Yes | ![Actively Maintained](documentation/images/green.svg) |

core/arch/arm/plat-imx/conf.mk

@@ -29,6 +29,7 @@ mx6s-flavorlist = \
 mx7-flavorlist = \
 	mx7dsabresd \
 	mx7swarp7 \
+	mx7swarp7_mbl \
 	mx7dclsom \
 
 imx8mq-flavorlist = \
@@ -105,6 +106,16 @@ CFG_BOOT_SECONDARY_REQUEST ?= n
 $(call force,CFG_TEE_CORE_NB_CORE,1)
 endif
 
+ifneq (,$(filter $(PLATFORM_FLAVOR),mx7swarp7_mbl))
+CFG_DDR_SIZE ?= 0x20000000
+CFG_NS_ENTRY_ADDR ?= 0x87800000
+CFG_DT_ADDR ?= 0x83100000
+CFG_BOOT_SECONDARY_REQUEST ?= n
+CFG_EXTERNAL_DTB_OVERLAY = y
+CFG_IMX_WDOG_EXT_RESET = y
+$(call force,CFG_TEE_CORE_NB_CORE,1)
+endif
+
 ifneq (,$(filter $(PLATFORM_FLAVOR),mx6qsabresd mx6dlsabresd \
 	mx6dlsabrelite mx6dhmbedge mx6dlhmbedge))
 CFG_DDR_SIZE ?= 0x40000000