Boot from SD card


#1
  • Can this device boot from SD card? How do you want to support multiple operating systems at the same time? dual boot?
  • Does it support TWRP?

-ropoman


#2

Yes it supports booting from card. See here.

I have seen TWRP on the S905x, so I would bet will make it to the KV


#3

Yes, as @RDFTKV mentioned above, Khadas VIM support boot from SD card, and now we release LibreELEC OS also boot from SD card.
And the VIM also support dual booting mode from both onboard eMMC or SD card, we design a Function button to support booting mode chose as following:

  • power on without pressing the Function button, will normally boot from onboard eMMC
  • power on and pressing the Function button, will boot from the SD card.

Of course, developers can also achieve multiple OS booting with other ways, we design with additional buttons just to match different use case for users.


#4

Can I add some follow-up questions?

  • Since you write trans flash card instead of sd card, are there any significant differences? Will all micro sd cards work? Can I expect a decent performance running from a sandisk extreme plus with 95MB/s. How fast is the onboard eMMC (BGA169-INAND)?
  • Are there instructions on how to make a bootable android sd card?

#5

Yes, i think all micro sd cards work, but the on board eMMC-V5.0 specs as 400MB/s is much faster then sd card.

We haven’t done the bootable android on sd card yet, just done LibreELEC/buildroot/ubuntu on sd card.
may i know why you need bootable android on sd card rather then on eMMC?


#6

Main reason is to be able to play with a new os for a while without deleting the installed os. Also I can make easily backups of sd cards. How would I backup the installed os? That is why I also asked about TWRP


#7

Well, i see.
will update tutorials about these at Khadas Docs.


#8

A user at Freaktab, balbes150 has produced a backup solution for the S905. I have not looked lately, but maybe he has done the same for the S905x.
It is called ddBR(post#29) for “dd Backup and Restore”. His method requires no physical connection to the device. He has a PDF(English and Russian) here for those that are curious about it

Of course, this is for information, I have no idea if it will work on the VIM… Any attempt to use ddBR is done at the risk of the user. That being said, it worked well on an S905.


#9

OK I have been in touch with balbes150, he said ddBR should work on most any box that can run Linux, but with some very simple adjustments.
So ddBR should be a viable solution to backing up the VIM’s installed OS.


#10

I do believe Vim will have it’s own way of backing up the OS, and i don’t believe it will use twrp, it will probably use something specially designed for the board.


#11

I create a bootable LibreELEC sdcard using the dd commands, and trying to boot the LibreELEC in SD card by pressing the Function key when reset/poweron, but no luck, the board still boot from eMMC.
From the uboot log, I think the uboot detect the function key pressed, but no action:

amlkey_init() enter!
[EFUSE_MSG]keynum is 4
[BL31]: tee size: 0
[KM]Error:f[key_manage_query_size]L507:key[usid] not programed yet
[KM]Error:f[key_manage_query_size]L507:key[mac] not programed yet
[KM]Error:f[key_manage_query_size]L507:key[deviceid] not programed yet
get_cpu_id flag_12bit=1
Detect function key
gpio: pin GPIOAO_2 (gpio 102) value is 1
gpio: pin GPIOAO_2 (gpio 102) value is 1
get_cpu_id flag_12bit=1
Product checking: pass!

Also, I can see the SD card information and files in the SD card partition by using the mmcinfo and fatls commands, so, I think the SD card is OK.

I don’t know what results this problem, how can I debug?
And can you give the commands to booting the LibreELEC and android from SD card? Something like:
fatload 0xXXXX mmc 0:1 Kernel
set bootargs XXXXX
bootm/bootz


#13

Same here, I really would like to know how to boot from the SD card.

I don’t have the UART cable, pushing the FUNCTION button didn’t work for me.


#14

How to boot android from the SD card? I have suffered damage eMMC