ECE 424 Embedded Systems Design Lecture 11: Embedded Platform Boot Sequence Chapter 6 Ning Weng
ECE 424 Embedded Systems
Design
Lecture 11: Embedded Platform Boot Sequence
Chapter 6Ning Weng
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Introduction
• What is boot sequence?• Why we care?
• 2 or 3 phases─ BIOS/fireware: from processor reset vector─ OS boot loader: from storage devices─ OS
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Multi-core/threads Boot• Basic terms
─ Thread, core, package and SOC, • Bootstrap processor (BSP), Aps• Wait-for-SIPI state: wait for startup inter processor
interrupt
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Image Storage Technologies
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S1: Power Sequencing
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S2: Reset• Reset vector: the location of these initial
processor instructions─ Inel 16 bytes
• Hardware and software reset
• Operation modes─ Real─ Flat protected mode─ Segmented protected mode
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S3: Early Initialization • CPU and memory controller initialization
─ CPU─ IA Microcode update─ Device Initialization─ Memory Configuration─ Post-memory setup─ Shadowing─ AP Initialization
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S4: Advanced Initialization
• Platform related initialization, peripheral-specific
─ GPIO─ Interrupt/Cache controller─ Timers─ PCIe bus─ Image storage
• …
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S5: Boot Loader• Identifying the image and handoff to the image• See next slides for overall boot flow
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PXE (Networking Booting)
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Announcement• Read chapter 7 for OS overview• Friday, 9/21 Exam 1• HW and Lab due
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