BBeOS/docs/PHASE_1_IMPLEMENTATION.md

Phase 1 Implementation: Hardware Access & Bootloader Research

Current Status

Based on our research, we have comprehensive hardware specifications and bootloader analysis. Now we need to implement practical testing and development.

Implementation Plan

1. Development Environment Setup

Required Tools

• Cross-compilation toolchain for ARMv7
• QEMU for ARM emulation
• Buildroot for minimal rootfs
• Linux kernel source (mainline + CAF patches)
• Device tree compiler (dtc)
• Fastboot/ADB tools

Setup Commands

# Install cross-compilation tools
sudo apt install gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf

# Install QEMU for ARM
sudo apt install qemu-system-arm

# Install device tree compiler
sudo apt install device-tree-compiler

# Install Android tools
sudo apt install android-tools-fastboot android-tools-adb

2. Minimal Kernel Configuration

Base Configuration

• Start with msm8960_defconfig from mainline kernel
• Add essential drivers for Q20 hardware
• Enable debug interfaces and console output
• Configure minimal filesystem support

Key Configurations

CONFIG_ARM=y
CONFIG_CPU_32v7=y
CONFIG_ARCH_MSM=y
CONFIG_MSM8960=y
CONFIG_SERIAL_MSM_CONSOLE=y
CONFIG_MMC=y
CONFIG_MMC_MSM=y
CONFIG_DRM_MSM=y
CONFIG_SOUND_MSM=y
CONFIG_INPUT=y
CONFIG_KEYBOARD_MSM=y

3. Device Tree Development

Base Device Tree

• Create q20.dts based on MSM8960 reference
• Define memory map and CPU configuration
• Add essential peripherals (UART, MMC, GPIO)
• Configure display and input devices

Key Device Tree Nodes

/ {
    model = "BlackBerry Classic Q20";
    compatible = "blackberry,q20", "qcom,msm8960";
    
    memory {
        device_type = "memory";
        reg = <0x0 0x80000000>;
    };
    
    chosen {
        stdout-path = "serial0:115200n8";
    };
};

4. Minimal Root Filesystem

BusyBox-based Rootfs

• Use Buildroot to create minimal rootfs
• Include essential tools (sh, ls, mount, etc.)
• Add network tools for debugging
• Configure basic init system

Essential Packages

busybox
dropbear (SSH server)
iw (Wi-Fi tools)
alsa-utils (audio)

5. Boot Image Creation

Android Boot Image Format

• Create zImage from kernel
• Build minimal initramfs
• Package as Android boot image
• Test with QEMU first

Boot Image Structure

boot.img:
├── kernel (zImage)
├── ramdisk (initramfs)
├── device tree (q20.dtb)
└── second stage (optional)

6. Testing Strategy

QEMU Testing

• Test kernel boot in QEMU
• Verify device tree loading
• Test basic hardware emulation
• Debug boot issues

Hardware Testing (when available)

• Test on actual Q20 device
• Verify debug interface access
• Test bootloader interaction
• Document hardware behavior

7. Debug Interface Setup

Serial Console

• Configure UART for console output
• Set up USB-to-serial communication
• Enable kernel console messages
• Test debug output

Network Debug

• Configure network interface
• Set up SSH access
• Enable remote debugging
• Test network connectivity

Implementation Steps

Step 1: Environment Setup

1. Install development tools
2. Download kernel source
3. Set up cross-compilation
4. Configure build environment

Step 2: Kernel Configuration

1. Create base kernel config
2. Add MSM8960 support
3. Enable essential drivers
4. Test kernel compilation

Step 3: Device Tree

1. Create base device tree
2. Add hardware definitions
3. Test device tree compilation
4. Verify hardware detection

Step 4: Root Filesystem

1. Configure Buildroot
2. Build minimal rootfs
3. Add essential tools
4. Test rootfs boot

Step 5: Boot Image

1. Create boot image
2. Test with QEMU
3. Debug boot issues
4. Prepare for hardware testing

Step 6: Hardware Testing

1. Test on actual device
2. Verify hardware access
3. Document findings
4. Plan next phase

Success Criteria

Phase 1 Complete When:

• Development environment is set up
• Kernel compiles and boots in QEMU
• Device tree loads correctly
• Minimal rootfs boots
• Debug interfaces are working
• Hardware testing plan is ready

Phase 2 Ready When:

• Basic kernel is working
• Hardware access is confirmed
• Boot process is understood
• Development workflow is established

Risk Mitigation

Technical Risks

• Bootloader locked: Use recovery mode or EDL
• Hardware not accessible: Focus on emulation first
• Drivers not working: Use generic drivers initially

Development Risks

• Limited documentation: Rely on community resources
• Complex hardware: Start with basic functionality
• Time constraints: Focus on essential features

Next Phase Preparation

Phase 2 Requirements

• Working kernel and rootfs
• Basic hardware access
• Debug interface setup
• Development workflow established

Phase 2 Goals

• Boot on actual hardware
• Basic hardware drivers working
• User interface framework
• Core system functionality