Software; Introduction; Boot-Loader/Target Monitor/Startup Firmware; Initialization Flow - Intel IQ80315 Board Manual

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Intel IQ80315 I/O Processor Evaluation Platform
4.0

Software

4.1

Introduction

This section covers requirements for software and firmware running on the Intel
Customer Reference Board.
4.2

Boot-Loader/Target Monitor/Startup Firmware

The targeted boot-loader for the IQ80315 CRB is RedBoot*. RedBoot is a complete bootstrap
environment based on the eCos Hardware Abstraction Layer. RedBoot supports downloading and
debugging gcc-based and eCos applications, flash and network booting of the Linux* kernel, and
downloading and updating of flash images remotely via serial or Ethernet connections. RedBoot
can be used as for product development, debug, and deployment in final products. RedBoot
provides a target-side hook known as a "stub" (or gdb-stub) that enables gdb, the GNU debugger,
to communicate with applications built with gcc or g++ running on IQ80315 CRB. RedBoot source
code is covered under the eCos license.
4.2.1

Initialization Flow

RedBoot* is in charge of booting the IQ80315 CRB to a known state where programs can be
downloaded and debugged. The basic outline of how RedBoot boots the platform is described
below.
The basic initialization sequence for RedBoot is as follows:
1. Disable interrupts. (Technically they are disabled at reset, but for soft reset this is included.)
2. Initialize the Peripheral Bus Interface (PBI) by initializing base address registers (BARs),
Look-Up Tables (LUTs), and timings for board peripherals.
3. Enable I-cache.
4. Re-locate flash.
5. Set TTB and enable MMU.
6. Read DDR DIMM serial presence detect EEPROMs for memory parameters.
7. Set memory parameters.
8. Turn DDRAM on.
9. Enable data cache.
10. Enable BTB.
11. Flush all.
12. Clear CPU and SDRAM ECC error logs.
13. Test battery.
14. Enable CPU ECC.
15. Enable SDRAM ECC.
16. Scrub loop: Write zeroes to all SDRAM memory locations.
17. Scrub loop: Write zeroes to all SRAM memory locations.
18. Enable SRAM.
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®
Intel IQ80315 I/O Processor Evaluation Platform Board Manual
®
IQ80315