AM335x kernel and filesystem load via UART

veera anjaneyulu

Expert 1920 points

Hi All,

we are using uart0 boot configuration.U-boot booted with uart0 successfully then how to boot kernel images with uart0.we are using ti-processor-sdk-3.00.00.4 ,kernel version 4.4.12 and u-boot 2016-5.

Any body kernel image and filesystem booted with uart0.How we will boot.

Thanks

veera

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Yordan Kamenov over 9 years ago

TI__Mastermind 42515 points

Hi veera,

the usual procedure after booting U-boot from UART is to configure tftp or NFS to load the
kernel and filesystem via network (and then they can be flashed to emmc). You can check those wikis:

processors.wiki.ti.com/.../AM335x_U-Boot_User's_Guide
processors.wiki.ti.com/.../Linux_Core_U-Boot_User's_Guide
processors.wiki.ti.com/.../Booting_Linux_kernel_using_U-Boot

It should be possible to load the kernel and initrd or initramfs via UART, but loading full filesystem
using uart and kermit protocol is not trivial and I didn't find information of someone who did this.

Regards,
Yordan

0 veera anjaneyulu over 9 years ago

Expert 1920 points

Hi All,

We have am335x-evm based custom board.In our case emmc conncected to mmc0 interface and uart booting source.we dont have sdcard and ethernet,usb ,nand interfaces.

we are working with u-boot2016-05,kernel-version is 4.4.12,rootfs filesystemd size is 80MB.

How can we flash the images into emmc chip.with out having the above interface.only through uart interface.

Another alternate method only uart booting.Through uart booting we loaded u-boot images.ie ok.But we loaded kernel images also but we are not getting kernel boot messages.

Can any body tried please explain me the steps and please provide me any related links also how to flash the images from uart to emmc.

Thanks

veera

0 Biser Gatchev-XID over 9 years ago in reply to veera anjaneyulu

TI__Guru**** 393215 points

You should have considered this when designing the board. Loading kernel and file system through UART, even if possible, will likely take something like 2 hours or more (>80MB @ 115200bps - you can calculate yourself). As I see it your only option is to program the eMMC before soldering it on the PCB or redesign the board.

0 Biser Gatchev-XID over 9 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

Besides this, if your eMMC is connected to MMC0, as you state, you will very likely not be able to boot from it. See section 26.1.7.5.2 from the AM335x TRM Rev. O for details.

0 veera anjaneyulu over 9 years ago in reply to Biser Gatchev-XID

Expert 1920 points

Hi Biser,

Thanks for your reply.

We dont have control over the board design .we are providing software support only.Flashing through uart is development purpose only.Finally It may be done through emmc before soldering.

please provide me the steps or please provide me any related links also how to flash the images from uart to emmc.

Thanks
veera

0 Yordan Kovachev over 9 years ago in reply to veera anjaneyulu

TI__Guru**** 161600 points

Hi Veera,

You could try loadb or loady to transfer the kernel image into the ram. But I am not sure how to continue with the filesystem... as far as I know you need some storage device to load from it.

Let me check further and get back.

Best Regards,
Yordan

Processors

Processors forum

AM335x kernel and filesystem load via UART