AM6442: what is difference of the way to Linux booting

Genius 3186 points

Part Number: AM6442

May I have some questions about AM64x Linux booting?

Q1:

I think there are 2 way to boot Linux, using Linux-SDK U-boot, And using Linux SBL(MCU+SDK).

What is the difference?

I think boot timing of another core that not use in linux is mainly difference.

Q2:

Is this correct booting process about the 2 way of boot process?

1. boot from U-boot

tiboot3.bin -> tispl.bin -> u-boot.img -> Linux

2. boot from SBL

SBL.appimage -> Linux.appimage ->u-boot.img -> Linux

Q3:

If I use Linux SBL for SoC boot,

Why we could select as boot memory only OSPI or eMMC?

https://software-dl.ti.com/mcu-plus-sdk/esd/AM64X/09_00_00_35/exports/docs/api_guide_am64x/SBL_BOOTING_LINUX_OSPI.html

Thanks,

over 2 years ago

+1 Hong Guan64 over 2 years ago

TI__Guru 68080 points

Hello,
Please refer to the reference boot flow on Q1/Q2:
- Linux
software-dl.ti.com/.../UG-General-Info.html
- MCU+SDK
software-dl.ti.com/.../SBL_BOOTING_LINUX_OSPI.html
software-dl.ti.com/.../SBL_BOOTING_LINUX_EMMC.html

Let me pass it to my colleague on Q3.

Best,
-Hong

+1 Prashant Shivhare over 1 year ago

TI__Guru 68731 points

Hi Gr-san,

GR said:
Why we could select as boot memory only OSPI or eMMC?

This is because we only have bootloaders, which support booting Linux, for OSPI & eMMC memory. These bootloaders are sbl_ospi_linux & sbl_emmc_linux respectively. So, when using these bootloader one must accordingly use OSPI or eMMC boot mode.

Regards,

Prashant

0 GR over 1 year ago in reply to Prashant Shivhare

Genius 3186 points

Hi Hong-san, Prashant-san,

Thanks for your information.

Prashant Shivhare said:
This is because we only have bootloaders

This mean SDK 9.00 is supportiong only SBL boot form OSPI and eMMC for Linux boot?

Could I develop Linux SBL boot from another device(e.g. UART boot) ,reference by SDK SBL CCS project?

Or is there any issue develop SBL that boot from not OSPI/eMMC by hardware?

Best regards,

+1 Prashant Shivhare over 1 year ago in reply to GR

TI__Guru 68731 points

Hi GR-san,

GR said:
This mean SDK 9.00 is supportiong only SBL boot form OSPI and eMMC for Linux boot?

Yes, this is indeed the case.

GR said:
Or is there any issue develop SBL that boot from not OSPI/eMMC by hardware?

There should not be any issue.

In fact, the AM62x MCU+ SDK already has support for Linux SBL boot from UART. This Linux SBL (sbl_uart_linux) in AM62x receives all the images including linux.appimage over UART and boots those images. Once linux.appimage boots, it then boots Linux from SD card.

Regards,

Prashant

0 GR over 1 year ago in reply to Prashant Shivhare

Genius 3186 points

Hi Prashant-san

Thanks for your information.

Prashant Shivhare said:
There should not be any issue.

I understand.

Is there any plan in AM64 SDK for boot Linux SBL by another boot device(e.g. GPMC, USB... )?

You let me that AM62 could use UART for Linux SBL, So I think AM64 will be soon supported UART Linux SBL.

Best regards,

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AM6442: what is difference of the way to Linux booting