Overview:
| CPU | Adelie |
| Data | 16?/32 bits |
| Memory | 32 bits |
| Registers | 32 |
| Architecture | Not currently relevant |
| Technology | FPGA |
| Status | Retargeting GNU binutils |
| Successor | None |
| Time period | May 2019 - present |
Problems:
- None.
Lessons:
- Linux is not user-friendly.
- Linux is programmer friendly
My first semester at college, I started reading Computer Organization and Design by Patterson and Hennessy because I wanted to learn how to build more advanced CPUs. There were two concepts that the authors seemed to push: make the common case fast, and judge a computer by the speed of compiled code. Ever since then, I have wanted to try making a computer that adhered to this philosophy. That computer is Adelie. Unlike my other computers, making the ISA compatable with a C compiler is one of the most important goals. Currently I am trying to retarget GCC to Adelie and soldify the ISA as I go. That is not to say I don't have an architecture in mind. There is already an emulated version running on an ATmega328P.
I tried to keep the instructions in variable length 16 or 32 bit words to save memory and increase the speed of the instruction fetch. I also tried to make the instructions easy to decode, which makes the first instruction word look suspiciously similar to MIPS. Since the instruction length varies between 16 and 32 bits, I may try to make a smaller 16-bit version in addition to the 32-bit version.
Before I do any more work on Adelie, my current task is to retarget a compiler to it. I chose GCC since other people had retargeted it, and it is a good compiler. They may not be the best reasons, but I would like to try anyway. I found what seems like the only tutorial on how to retarget GCC, and it is not bad considering it is from 2008. I am currently working on getting the assembler working. It is having a bit of a problem managing labels, which is causing the linker to choke.
2/7/2020
The assembler is working! I am now working on updating Binutils to version 2.34.
Why did I name the computer Adelie? I like gentoo penguins, but that name was already taken. Adelie was the next on the list.
7/24/2019 - Oops. It looks like an Adelie does exist. Oh well.
1/8/2020 - Oops. An Adelie CPU exists. That could be a genuine problem. Its ISA is RISC-V though, while mine is a homebrew.
Links:
Files: