# TQMa6UL Yocto BSP – Mirror & Build Documentation

**Project ID:** TQMA6-YOCTO-2038
**Date:** 2026-03-01
**Target Hardware:** TQMa6UL-AB (i.MX6 UltraLite) on MBa6ULx Carrier
**Yocto Version:** Scarthgap (5.0.11) LTS
**Objective:** Create offline mirror for software approval, ensure 2038 compliance

---

## Overview

This project addresses the requirement to migrate from legacy PTXdist-based BSP
to Yocto Project for TQMa6UL hardware. The primary driver is Year 2038
compliance for military/long-term deployments.

### 2038 Problem Context

The Year 2038 Problem (Y2K38) affects 32-bit systems using signed 32-bit time_t:
- Maximum representable time: 03:14:07 UTC on 19 January 2038
- Systems will overflow and behave unpredictably after this date
- Critical for military/aerospace systems with 15+ year service life

### Solution: Yocto Scarthgap + musl

Yocto Scarthgap (5.0 LTS) with musl libc provides:
- 64-bit time_t by default on 32-bit ARM (musl 1.2+)
- Long-term support until April 2028+
- Comprehensive license manifests for approval

## Board Identification

| Field | Value |
|-------|-------|
| **SoM** | TQMa6UL (sticker: `TQMA6U-AB`) |
| **SoC** | NXP i.MX6 UltraLite (Cortex-A7, single core) |
| **Carrier** | MBa6ULx |
| **Machine** | `tqma6ul-multi-mba6ulx` |
| **BSP Config** | `mainline` (**not** `imx`!) |

> ⚠️ **Critical:** The TQMa6UL machines are **only** available in the `mainline`
> config template. The `imx` config does NOT include this board.

## Verified Build Configuration

*Tested 2026-03-01 on Debian 13 (Python 3.13):*

```
BB_VERSION           = 2.8.0
BUILD_SYS            = x86_64-linux
NATIVELSBSTRING      = universal
TARGET_SYS           = arm-tq-linux-musleabi
MACHINE              = tqma6ul-multi-mba6ulx
DISTRO               = spaetzle
DISTRO_VERSION       = 5.0.11
TUNE_FEATURES        = arm vfp cortexa7 neon thumb callconvention-hard
TARGET_FPU           = hard
```

### 2038 Compliance Status

| Component | Version | 2038-safe? | Notes |
|-----------|---------|-----------|-------|
| **Kernel** | Mainline 6.x | ✅ | 64-bit time syscalls |
| **musl libc** | 1.2+ | ✅ | 64-bit `time_t` since 1.2.0 |
| **Userspace** | Scarthgap | ✅ | Rebuilt against 64-bit `time_t` |
| **U-Boot** | Mainline | ✅ | No time_t issues in bootloader |

> **Note:** This BSP uses **musl libc** (`arm-tq-linux-musleabi`), NOT glibc.
> musl has provided 64-bit `time_t` unconditionally on all 32-bit architectures
> since version 1.2.0 (February 2020).

## Documentation

| Document | Description |
|----------|-------------|
| [2038 Compliance Analysis](docs/01-analysis/2038-problem-analysis.md) | Detailed 2038 risk assessment |
| [Mirror Creation Guide](docs/02-mirror-creation/step-by-step-mirror-creation.md) | Step-by-step build instructions |
| [License Summary](docs/03-license-analysis/license-summary.md) | License overview and compliance |
| [License Table](docs/03-license-analysis/UT-license-table.csv) | CSV format for import |
| [Air-Gapped Deployment](docs/04-deployment/corporate-network-deployment.md) | Offline build setup |

## Quick Start

```bash
# 1. Clone
git clone --recurse-submodules https://github.com/tq-systems/ci-meta-tq.git
cd ci-meta-tq

# 2. Setup
export ACCEPT_FSL_EULA=1
export MACHINE=tqma6ul-multi-mba6ulx
. ./setup-environment build_ut mainline
echo 'ACCEPT_FSL_EULA = "1"' >> build_ut/conf/local.conf

# 3. Fetch (for mirror creation)
bitbake tq-image-small-debug --runall=fetch

# 4. Build
bitbake tq-image-small-debug
```

## References

- [TQ-Systems ci-meta-tq](https://github.com/tq-systems/ci-meta-tq)
- [TQMa6UL Product Page](https://www.tq-group.com/en/products/tq-embedded/arm-architecture/tqma6ul/)
- [Yocto Scarthgap Docs](https://docs.yoctoproject.org/5.0/)
- [musl 64-bit time_t](https://musl.libc.org/time64.html)