Booting options (SBC Lynx)

Info Box Applies to SBC Lynx

SBC Lynx is extremely flexible in terms of hardware configurations. This document describes main options related to booting. In case you need a configuration that is not listed here, please contact [mailto:sales@dave.eu

Contents

IntroductionEdit

SBC Lynx is built upon NXP iMX6UL processor. This component supports several booting options that are summarized here. Reading of that section is recommended for understanding this document.

Interested reader may find an exhaustive discussion of iMX6UL boot options in the Applications Processor Reference Manual.

Available optionsEdit

By default, eFUSE bits are not supported as bootstrap option [1]. Thus two actual modes can be selected by S12.1 and S12.2 switches, as listed in the following table.

BOOT_MODE[1:0]	Boot type	S12.2 (BOOT_MODE1)	S12.1 (BOOT_MODE0)	Notes
00	Boot from eFUSEs	off	off	Supported on request only
01	Serial downloader	off	on
10	Internal boot	on	off	Default
11	reserved

[1] Nevertheless, SBC Lynx can support this option. This is a clear example of a feature that can be implemented on request. For more information please contact department.

Internal bootEdit

When Internal boot mode is selected, GPIO override technique is used to

selection of the device from which the Boot ROM retrieves Program Image along with several further device-specific configuration settings, can be done in two different ways, depending on BT_FUSE_SEL bit:

• 0 (shipped value): GPIOs
  • This technique - also known as GPIO override - is typically used during the development stage. It allows to use 24 GPIOs (specifically LCD1_DATA[23:00]) to configure BOOT_CFG bits.
• 1: eFUSE.
  • In this case BOOT_CFG bits are fetched from OTP memory.

Serial downloaderEdit