Emmc and sd card . Grub?


(Troumad) #1

Hello

I have use this : http://www.fw-web.de/dokuwiki/doku.php?id=en:bpi-r2:storage
Thank’s you !

The only problem was the size of the OS-image. I have use a SDD for put it.

Why can I not boot in the emmc when there is a SD card ? I use Debug-UART ( thank’s for http://www.fw-web.de/dokuwiki/doku.php?id=en:bpi-r2:debug-uart ), but I have see nothing in the boot for choose the device for the boot. Can I install a grub in the SD card ? Has someone test it ?


(Frank W.) #2

You can bootup from sd-card and run parted to resize rootfs of emmc.

imho there are some hacks resizing rootfs while running but be careful with them.

R2 boots sd or if no sd-card is bootable try emmc. You can change this with hw-rev 1.2…there is a switch above sd-slot to change this behaviour. As i have only rev 1.1 i cannot test it.

As an alternate way you can set root in uenv.txt of sdcard to mmcblk1p2 to boot rootfs from emmc,but kernel is still loaded from sdcard

Imho you cannot use grub because grub is x86 and will need hw-support. Why do you want another bootloader? You can use my uboot if not using it already. 2019-1 with ethernet is on my github


(Troumad) #3

I have a first boot loader in the SD card. I have move my configuration in the emmc. It was only for save my new config file in the SD Card.
I could not easily access the BPI-R2 when it will be in its final place.


(Frank W.) #4

:thinking: i don’t really understand what you want to say…

you need bootloader (uboot) also in emmc…config should also be there, you can test emmc-boot by ejecting sd-card

if you have uboot running on emmc you can build a test-environment on sdcard (modifying root and maybe the Partition for kernel). If you use my recent Kernel (2018+) bootpartitions will be recognized via selectmmc

you can change this (by override) to set a fixed device to get kernel loaded from it, but uboot+its config is still loaded from sd-card if one is available…

for rootfs you have to change root= in uenv.txt


(Troumad) #5

I want use the SD card as a SSD disk. I want put it or remove it with all for the boot in the emmc.

I think it’s too difficult for me. I do not understand English well enough. My first problem is my English.

I have a SDD disk and it will be good enough.


(Frank W.) #6

you want to use sd-card only for storing your files but boot from emmc? why not using sata to connect a real ssd? sd-cards also having limited write-cycles

which hw-revision do you use?


(Troumad) #7

I don’t know my hw-revision.


(Cioby23) #8

It’s written on the BPI-R2 board in the middle of it.


(Troumad) #9

BPI-R2 V1.2

It’s good ?


(Frank W.) #10

yes, Then you have the switch for chosing boot-device. Set this to emmc and you can leave your sd-card in…r2 should boot from emmc if you have it configured right


(Troumad) #11

I have try to move the switch. I have boot to the SD Card.


(Frank W.) #12

Does it boot without sd-card? I guess you miss anything on emmc