Phase 1: The Pocket Flasher

From a bare ESP32 board to a self-contained SD card flasher. We initialize the display and touchscreen, talk to the SD card over SPI, create a GPT partition table, format a FAT32 filesystem, decompress the workstation payload, and write a verified bootable card — all in under 2,000 lines of C on a microcontroller with 520 KB of RAM.

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Table of contents

• Chapter 27: The Pocket Flasher
• Chapter 28: Setting Up the ESP32
• Chapter 29: Driving the Display
• Chapter 30: Talking to the SD Card
• Chapter 31: Creating a GPT
• Chapter 32: Building FAT32
• Chapter 33: Packing the Payload
• Chapter 34: Flash!