dinartem

5 ms·

1.
by dinartem 2y ago
We still used the lwarx/stwcx pair to implement atomic operations, but to avoid the hardware bug a strict rule needed to be followed. Rule: On a given hardware thread (there are two hardware threads per processor on the Xbox 360), ever
2.
by dinartem 2y ago
So the PPC instruction set uses lwarx (load word and reserve indexed), and stwcx (store word conditional indexed), along with variations for word size, to implement atomic operations such as interlocked-increment and test-and-set. So on PPC
3.
by dinartem 2y ago
Actually Tracy never made it to Austin. He was going to fly in later in the week to continue bring-up, but since we were done by Wednesday, we just sent the chips to Redmond and he continued there. He was of course always available on the p
4.
by dinartem 2y ago
I called the simulator Sbox and it was just a simple console app. I didn't implement the GPU, so no graphics just the hypervisor and kernel and some simple non-graphics apps. I made it so that you could build the Xbox 360 kernel on you
5.
by dinartem 2y ago
One challenge was that while I started working on the Xbox 360 about three years before it would ship, we knew that the custom CPU would not be available until early 2005 (first chips arrived in early February). And there was only supposed
6.
by dinartem 2y ago
Good times. I was the developer at Microsoft who designed the Xbox 360 hardware security, wrote all the boot loaders, and the hypervisor code. Note to self: you should have added random delays before and after making the POST code visible o
7.
by dinartem 3y ago
No, I never spoke with them.
8.
by dinartem 3y ago
Xbox Security Protocol. We liked to add X to things back then.
9.
by dinartem 3y ago
That's a valid point about complex parsing. I remember being very concerned about adding unnecessary overhead to each packet during encapsulation. As for the SG, it primarily authenticated the Xbox machine account using Kerberos and th
10.
by dinartem 3y ago
Nice work! Always fun to see something I wrote long ago reverse engineered. The packet format was indeed inspired by ESP over UDP, and I named it XSP. After system link shipped with the original launch of the console, I also worked on Xbox