System boot and recovery via microSD card (BELK/BXELK)

Info Box Applies to Bora Applies to BORA Xpress Applies to BORA Lite

History

Version	Date	BELK version	Notes
1.0.0	November 2015	3.0.0	First release
2.0.0	December 2016	BELK 3.0.1 / BXELK 1.0.0	Added information about new kits
3.0.0	July 2017	BELK 4.0.0 / BXELK 2.0.0	Added information about new kits

Introduction

BELK provides a bootable microSD that can be used not only to quickly start the system, but also as a recovery method in case the primary boot device (eg. QSPI NOR flash) gets erased or corrupted. The following sections describe how to create a bootable SD card and how to configure the system for booting from SD. This article, for example, shows how to make use of such a card to restore the U-Boot image onto the NOR flash.

It is worth remembering that the bootable microSD card described in this article is not configured to perform a full boot sequence, including the operating system bootstrap. The bootable microSD card delivered along with the kit is set up to do a full bootstrap sequence, instead. For more details, please refer to this section.

How to create a bootable microSD card

BELK <= 3.0.2 / BXELK <= 1.0.1

This section describes how to create a new bootable microSD card from scratch for BELK <= 3.0.2 and BXELK <= 1.0.1. The following components must be available:

• FSBL built with Vivado 2014.4 as described here
• U-boot built in elf format, as described in here
• FPGA bitstream (optional).

The procedure is the following:

• from the Vivado 2014.4 SDK, apply the required patches to the main.c project file.This step can be done in two ways:
  • manually, directly modifying the main.c file adding the following code snippets:

----CUT----
	/*
	 * Unlock SLCR for SLCR register write
	 */
	SlcrUnlock();

+	*((u32 *)0xF8000830) = 0x003F003F;
+	*((u32 *)0xF8000834) = 0x003F003F;

	/* If Performance measurement is required 
	 * then read the Global Timer value , Please note that the
----CUT----

----CUT----
	/*
	 * Read bootmode register
	 */
	BootModeRegister = Xil_In32(BOOT_MODE_REG);
	BootModeRegister &= BOOT_MODES_MASK;

+	// always init QSPI
+	InitQspi();
	
	/*
	 * QSPI BOOT MODE
	 */
#ifdef XPAR_PS7_QSPI_LINEAR_0_S_AXI_BASEADDR
----CUT----

• • automatically, using the Apply Patch function and selecting the belk-sd-boot.patch file provided with the BELK (please refer to the following images):

Automatic patch applying (1/3)

Automatic patch applying (2/3)

Automatic patch applying (3/3)

• once the patch is applied, rebuild the FSBL project
• from the Xilinx Tools menu, select Create Zynq Boot Image
• select Create New BIF file and insert path and name of the .bif file
• in the Boot image partitions section, click on Add to browse and add the following files:
  • FSBL in .elf format, with bootloader as partition type
  • (optional) FPGA bitstream in .bit format, with partition type datafile
  • U-boot binary with .elf extension, with partition type datafile
• in the Output path section, browse and select the path where saving the boot.bin file
• on a PC, format the microSD card creating a FAT32 partition
• copy the boot.bin file to the microSD card FAT32 partition.

BELK-4.0.0 / BXELK-2.0.0

This section describes how to create a new bootable microSD card from scratch for BELK-4.0.0 and BXELK-2.0.0. The following components must be available:

• U-boot SPL and U-boot second stage built as described in here
• FPGA bitstream (optional).

The procedure is the following:

• on a PC, format the microSD card creating a FAT32 partition
• copy the following files to the microSD card FAT32 partition:
  • U-boot SPL: boot.bin
  • U-boot second stage: u-boot.img
  • Fpga bitstream .bit (optional): fpga.bit

How to configure the system for microSD boot

For Bora/BoraEVB systems please refer to this link.

For BoraX/BoraXEVB systems please refer to this link.

In case the microSD card provided along with the kit is used, the Programmable Logic is automatically programmed with the example design during the boot process.