Thread by @1nsane_dev

This is a thread on what we know about Apple’s prototyping and development process of manufactured products.

1/ All info here could be incomplete/wrong/outdated. I may (or may not) update this thread in future if I have enough things to share 😁
#AppleInternal #AppleCollection

2/ First of all, by digging into Apple’s internal assets, we almost immediately come across acronyms like EVT, DVT, PVT, OQC, DOE.
So what do those stand for?
Let’s take a few steps back.
In the industry environment, these process follow some sort of a standardized path:

3/ At Apple, a Golden Line is set up, consisting in a prototype assembly that serves as a reference for all other lines that are set up after it.
This line is to be considered as a template, which develops up to its ‘perfection’ and gets locked right after.

4/ The project enters in the PROTO stage and the first actual prototypes (as we know them) are physically built at Apple HQ. Usually, few distinct lines of the same product are built, each one presenting different experimental features.

5/ At the end of this stage, the models ‘surviving’ tests enter in the Development phase, which we know has different stages itself: ENGINEERING Validation Test (EVT), DEVELOPMENT Validation Test (DVT) and (mass) PRODUCTION TEST Validation (PVT).

6/ Standing to some reports from a former Apple employee, these stages are not always strictly identified, and it’s not always clear when a certain products leaves a stage to get into next one.
We can try to group up Apple’s protos by some common aspects linked to their stage.

7/ During EVT and DVT stages, all devices show up with a shape similar to the production units. They are provided with a Silicon that has main security features open to debug with SWD/JTAG tools. A parameter represents the security specs of each Silicon: CPFM (ChiPFuseMode).

8/ CPFM set to 0x00 allows both AP and SEP to be debugged, 0x01 allows debugging just on AP and 0x03 restricts debugging.
Externally, all regulatory is missing or replaced with XXX. A serial number is printed along with a project identifier on the back/side of the device.

9/ Sometimes, the project identifier is reported on the screen frame too.
Though is very rare, they can be still found with red plastic stickers that serves as lightning port protection, as well as other stickers that describe the unit assembly hardware specs.

10/ PVT stage is mass-production oriented: it’s divided in several test units, almost identical to what the final product will be, with the scope of assessing the quality of the product (Outgoing Quality Check, OQC …) and identifying all issues related to the production lines.

11/ Externally, they look very similar to production units, and may differ for just stickers and red plastic covers for the lightning ports.
Up to this point, I’ll take a break. These informations came from my personal researches, they can be wrong/incomplete.

12/ if you liked and want me to update more infos, go more in depth into details and show you some more devices, retweet my thread and comment with your opinions!