QEMU 1.5 was just released the other day, and in the "And much more..." category I'm happy to say that it includes Moxie support!

This release contains basic Moxie core support, with the imaginary "moxiesim" board support. I have some local changes that provide Marin SoC emulation, and can …

Good news: we can access external memory! The logic for my pseudo-static RAM controller is working, and big programs can finally run on hardware.

You may recall that I had previously only been accessing fake memory that was configured directly out of limited FPGA resources. I could squeeze a tiny …

Time for a quick update!

"Marin" is the name of my test SoC consisting of a wishbone wrapped 75Mhz big-endian MoxieLite bus master, along with two slave devices: embedded ROM and the Nexys3's 7-segment display. So, right now I can write some code into FPGA embedded ROM to manipulate the …

The Moxie ISA still needs quite a bit of tuning. Take branches, for instance. A beq instruction currently encoded like so...

`00001111xxxxxxxx iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii`

...where the "x"s represent "don't care" bits, and "i"s are a 32-bit absolute branch target. That's right -- branch targets are not PC relative! This …

I'll bottom line this one quickly:

• moxiedev is now maintained with git. Check it out like so..
  $ git clone http://moxielogic.org/moxiedev.git
• moxiedev now contains a partial u-boot port. It's "partial" because I fat fingered some commands and blew away four or five important files. They will have …

My moxie port of U-Boot, the Universal Boot Loader, has started working!

$ qemu-system-moxie -nographic -kernel u-boot
SDRAM :
        U-Boot Start:0x00001000
Using default environment

U-BOOT for "moxiesim"

=> version

U-Boot 2009.03-rc2-00013-gefb4734-dirty (Apr 02 2009 - 20:07:32)
=> printenv
bootargs=root …