mirkobe_89

Hi,
I've been finally able to boot armbian from emmc on banana pi p2 zero, and I'm going to share how I solved my issues.
 
Basically, somehow it seems that the bootloader was actually the culprit of my issue.
I compiled a new bootloader from armbian sources (following these instructions https://docs.armbian.com/Developer-Guide_Build-Preparation/), after applying 2 patches. I'm sharing the full procedure, I think it would be the clearest explanation possible.
 
git clone --depth 1 https://github.com/armbian/build; cd build;  
copy files banana_dts.patch and banana_defconfig.patch (attached below) inside both the userpatches folder and the userpatches/u-boot (perhaps only this last folder is usefull, I don't know) ./compile.sh BOARD=bananapim2zero Done!

NOTE: This last command will build a full boot+kernel image. Since I was interested on the bootloader only, I extracted the first 4M from that image with dd command, and saved it into a u-boot-with-spl.bin file. Perhaps it would have been faster and easier to build directly the bootloader only through the command (which I did not try): ./compile.sh BOARD=bananapim2zero 'compile_uboot'  
Here are the 2 patch files:
banana_dts.patch:
diff --git a/arch/arm/dts/sun8i-h2-plus-bananapi-m2-zero.dts b/arch/arm/dts/sun8i-h2-plus-bananapi-m2-zero.dts index d277d043..be57ce08 100644 --- a/arch/arm/dts/sun8i-h2-plus-bananapi-m2-zero.dts +++ b/arch/arm/dts/sun8i-h2-plus-bananapi-m2-zero.dts @@ -107,6 +107,25 @@ }; }; +&mmc2 { + pinctrl-names = "default"; + pinctrl-0 = <&mmc2_8bit_pins>; + vmmc-supply = <&reg_vcc3v3>; + vqmmc-supply = <&reg_vcc3v3>; + bus-width = <8>; + non-removable; + status = "okay"; +}; + + +&mmc2_8bit_pins { + pins = "PC5\0PC6\0PC8\0PC9\0PC10\0PC11\0PC12\0PC13\0PC14\0PC15\0PC16"; + function = "mmc2"; + drive-strength = < 0x1e >; + bias-pull-up; + phandle = < 0x54 >; +}; + &ohci0 { status = "okay"; };  
banana_defconfig.patch:
diff --git a/configs/bananapi_m2_zero_defconfig b/configs/bananapi_m2_zero_defconfig index 09d0517c..e47e7808 100644 --- a/configs/bananapi_m2_zero_defconfig +++ b/configs/bananapi_m2_zero_defconfig @@ -6,3 +6,6 @@ CONFIG_DRAM_CLK=408 CONFIG_MMC0_CD_PIN="" CONFIG_DEFAULT_DEVICE_TREE="sun8i-h2-plus-bananapi-m2-zero" # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set +CONFIG_VIDEO_DE2=n +CONFIG_MMC_SUNXI_SLOT_EXTRA=2 +CONFIG_SUN8I_EMAC=y  
BR