Trim-Slice U-Boot

From Trim-Slice Wiki

Contents 1 Introduction 2 Supported O/S boot sources 3 O/S boot sequence 4 Quick U-Boot command reference 4.1 Information commands 4.2 Memory commands 4.3 Execution control commands 4.4 Download commands 4.5 Environment variables commands 4.6 File system support commands 4.7 GPIO support 4.8 I2C support 4.9 PCI support 4.10 SD/MMC support 4.11 SPI flash support 4.12 USB support 4.13 Miscellaneous commands

Introduction

The Trim-Slice is using U-Boot boot-loader for low-level initializations and operating system loading. U-Boot is an open source firmware for a wide range of embedded systems (e.g. PowerPC, ARM, MIPS, x86, ColdFire, AVR32, NIOS, etc.). In this page we discuss only features and use cases related to Trim-Slice. For more information on U-Boot, please refer to Official U-Boot Homepage.

Supported O/S boot sources

The Trim-Slice U-Boot allows booting the operating system from the following Trim-Slice storage devices and interfaces:

• Front SD card - intended to be used as the primary removable storage for software installations and updates.
• External USB storage - may be used as an alternative removable storage.
• Micro-SD card - intended to be used as a non-removable storage for O/S images.
• Internal SATA storage - intended to be used as a non-removable storage for O/S images.
• GbE interface - may be used for network O/S boot.

O/S boot sequence

The Trim-Slice O/S boot sequence is implemented with a boot script designed as a set of pre-defined U-Boot environment variables.

Altering the default boot sequence may preclude using Trim-Slice software update tools such as O/S installer.

The boot script searches the different Trim-Slice boot devices for a partition containing a valid boot.scr file in the / or /boot/ directory.

The boot script will attempt to boot from the various boot devices in the following order:

• Front SD card
• External USB storage
• Micro-SD card
• Internal SATA storage

Quick U-Boot command reference

This section provides quick U-Boot command reference. To get more information about a specific command, type help [command] in the U-Boot command line.
Please refer to the U-Boot project documentation for detailed description of the commands listed below.

Information commands

• bdinfo - print Board Info structure
• coninfo - print console devices and information
• help - print online help

Memory commands

• base - print or set address offset
• crc32 - checksum calculation
• cmp - memory compare
• cp - memory copy
• md - memory display
• mm - memory modify (auto incrementing)
• mtest - simple RAM test
• mw - memory write (fill)
• nm - memory modify (constant address)
• loop - infinite loop on address range

Execution control commands

• source - run script from memory
• bootm - boot application image from memory
• go - start application at address 'addr'
• loop - infinite loop on address range
• exit - exit script

Download commands

• bootp - boot image via network using BOOTP/TFTP protocol
• dhcp - invoke DHCP client to obtain IP/boot params
• loadb - load binary file over serial line (kermit mode)
• loads - load S-Record file over serial line
• loady - load binary file over serial line (ymodem mode)
• rarpboot - boot image via network using RARP/TFTP protocol
• tftpboot - boot image via network using TFTP protocol
• ping - send ICMP ECHO REQUEST to network host

Environment variables commands

• boot - boot default, i.e., run 'bootcmd'
• bootd - boot default, i.e., run 'bootcmd'
• editenv - edit environment variable
• printenv - print environment variables
• run - run commands in an environment variable
• saveenv - save environment variables to persistent storage
• setenv - set environment variables

File system support commands

• ext2load - load binary file from a Ext2 filesystem
• ext2ls - list files in a directory (default /)
• fatinfo - print information about a FAT file system
• fatload - load binary file from a FAT file system
• fatls - list files in a FAT file system directory (default /)

GPIO support

• gpio - CPU gpio access

I2C support

• i2c - I2C sub-system

PCI support

• pci - list and access PCI Configuration Space

SD/MMC support

• mmc - SD/MMC sub-system

SPI flash support

• sf - SPI flash sub-system

USB support

• usb - USB sub-system control
• usbboot - boot from USB device

Miscellaneous commands

• echo - echo arguments to console
• false - do nothing, unsuccessfully
• itest - return true/false on integer compare
• reset - Perform RESET of the CPU
• showvar - print local hushshell variables
• sleep - delay execution for some time
• version - print monitor version
• test - minimal test, like /bin/bash
• true - do nothing, successfully
• ? - alias for help