21 September 2024 - 27 September 2024
Table of Contents
- 1. MIT OCW
- 2. SJ grounds
- 3. Lapuz Peking/Panerus
- 4. Mill
- 5. EDA workflow
- 6. Spark/QEMU
- 7. Cross compilers
- 8. SCZ Front Step
- 9. Spacewire-like PHY
- 10. CA Root Key Generation
- 11. Compilers
- 11.1. Compiled Wikipedia PL/0 example
- 11.2. Work out overall plan.
- 11.3. Looking into LLVM MLIR.
- 11.4. ASDL
- 11.4.1. current smlnj C++ implementation incomplete
- 11.4.2. old versions asdl source fail to build with new versions of smlnj
- 11.4.3. old versions of smlnj not easily buildable on x8664
- 11.4.4. ancient binary of asdl 1.2 compiler seems to work
- 11.4.5. analyzing asdl 1.2 generated code
- 11.4.6. run in vm?
- 12. Piper dovecot
- 13. Various i686
- 14. piper
- 15. Buffalo WZR-HP-G300NH
- 16. SJC weather station
- 17. opencl
- 18. EPLDH
- 19. wktpqb
- 20. Mill Controller #2
- 21. Alum Rock Data Center
- 22. Virtual Orchestra
- 23. gat
- 24. RIOT drivers
- 25. mcd05 32 button/led box
- 26. AMD 2900 bitslice computing
- 27. Hitachi HD68B09E CPU
- 28. Rockwell R65F11
- 29. PLD programming
- 30. EPROM Programming
- 31. POSIT
- 32. MAME
- 33. More project ideas
- 34. David Davies
1. MIT OCW
1.1. 18.06sc (Linear Algebra)
1.1.1. Unit III: Exam 3
2. SJ grounds
2.1. Water leak
Mostly fixed. Need to stub out outside water galvanize pipe, which is unused and has it's own problems.
3. Lapuz Peking/Panerus
Laid out keys. Keys are to big for Burhan's "restaraunt" cases. Ray to think about the next steps.
4. Mill
4.1. Y axis servo and controller delivered to SCZ.
5. EDA workflow
5.1. FPGA programming
5.2. RV32I
Seeing if a very simple RV32I is possible at ~600 ice40 cells. Likely not possible with a barrel shifter unless a multiplier is used. Certainly won't be fast, if possible at all at this size. This comes out to 18 gates per bit, which seems to be a ridiculously low number. Need to refine counting methodology to count LUTs and flops separately. Maybe further refinements for post-placement utilization (for example, how many LUTs get combined with a flop vs. separate LUTs and flops).
5.2.1. 'almanor' RV32I
- Three port register file, simplify decoder (~1100 LUTs, 300 FFs, 4 BRAM)
Not too happy with the result. Messier than expected.
- Refactoring
Still trying to understand what's driving the gate count. need to do some scaling experiments (FF/LUT per bit for various constructs).
- Post-synthesis testbench
Fragility much reduced after aggressive process splitting.
- Verilator testbench
Started planning.
- CSR/Debug interfaces
Seeing if it's worth it to implement minimal CSR and debug interfaces
- Picosoc analysis
Understanding picosoc implementation as a reference
- Standard tests
- riscv-arch-test
Ported and running. After changing verilog memory image generation to use objcopy, and correcting JALR masking, all RV32I tests pass.
- riscv-torture
- Used picorv32 patches to generate test cases.
Tried generalizing the Scala code, but looks like it was going to require more changes than I was comfortable with making - particularly for the E reduced register profiles.
- Regex filter
Wrote a regex based filter to change opcodes and various ranges for RV32I, RV32E and RV64E.
- Tests pass
All torture tests pass.
- Used picorv32 patches to generate test cases.
- riscv-arch-test
- Compare with a pipelined implementation
Still thinking about it.
- Debug and Interrupt architecture
Working out what's needed.
5.3. RTX-2000
Pulled out the RTX-2000 manual. Going to be a slog if I do it.
5.4. Synthesizable sparc v8
5.4.1. Seeing what it takes to make 'bs' synthesizable.
No way. Need to start fresh.
5.4.2. make smaller than picorv32?
Want to see if I can get something substantially smaller than picorv32 - although I doubt it. Better to start with RV32I though.
5.4.3. Found a bug
in load base/offset register instructions.
5.4.4. Found maybe another bug
Not sure about condition codes on 'sub'. Difficulty porting to rv32 leads to questions.
5.4.5. Cleanups
Apparently never run though verilator. Cleaned up.
5.4.6. Need legion
Need to see if the UltraSparc 10 is still running for legion tests.
5.4.7. u10
- Serial port works so boot is trying to do something.
- Doesn't seem to respond to 'break'
Enhanced 'sp' to send break command.
- NVRAM battery is dead. Not a FRU.
Needs an invasive fix or part replacement. NVRAM held MAC address, so that would be unavailable so could explain not booting. DHCP database has programmed MAC for static IP assignment so that at least is recoverable.
- Video dongle.
Dongle works with VGA monitor. Updating NVRAM parameters on console allows system to boot.
- Recovered legion
Copied off legion simulator binaries.
6. Spark/QEMU
Tested QEMU sparc simulator running Solaris 5. Probably a reasonable alternative to using u10.
7. Cross compilers
7.1. Toolchain scripts running.
7.1.1. moxie-elf c, c++, and ada.
7.1.2. sparc-elf c, c++, and ada.
7.1.3. riscv-elf c, c++, and ada.
gdb riscv simulator seems to not handle logical right shifts correctly in 32 bit mode. Arithmetic right shift has specific checks for 32 bit mode, but logical right shift does not and is clearly right shifting a 64 bit value.
8. SCZ Front Step
8.1. Starting to fit.
Hanging up on something hidden.
8.2. Need to fix mistake under window.
Have a patch piece.
9. Spacewire-like PHY
Poking that this long-standing problem. Building infrastructure to test if it's possible to construct a PHY layer with acceptable BER to 50 MBit which should be sufficient for 32 16-bit channels at 48 KHz sample rate. Need to re-establish EDA workflow.
Not sure this is practical.
10. CA Root Key Generation
Nice to have an appliance that manages keys. Need to make this simple. Really don't have time for a science project. Too, bad, though. It kind of is a science project. Could just buy something from nitrokey https://www.nitrokey.com/ but I really don't want to spend money on it of I have hardware already. Looking at nitrokey in more detail, it doesn't seem to be any simpler than what I'm doing already.
10.1. First pass done
10.1.1. Based on https://pki-tutorial.readthedocs.io/en/latest/simple/
Interesting that the certs generated fail with openssl sserver testing because the cryptographic algorithms are too weak.
10.2. Need to be clear on security properties.
Definitely protect against remote access to private keys. How strong does the protection against local access need to be?
10.3. Simple hardware.
10.3.1. Use beagleboard with local interface
10.3.2. Use some modern device TPM
Need to export data for backup.
10.3.3. Or something that uses PKCS11 interface
10.4. USB Serial interface only but no credentials across USB I/F.
But this potentially exposes the hardware to remote access via the USB I/F when connected.
10.5. Use Sneakernet
Doesn't scale. Should use something so cert updates are automatable. But that's a science project it seems.
11. Compilers
11.1. Compiled Wikipedia PL/0 example
11.2. Work out overall plan.
Lots of moving pieces.
11.3. Looking into LLVM MLIR.
Will not use immediately, but perhaps trend in that direction.
11.4. ASDL
11.4.1. current smlnj C++ implementation incomplete
11.4.2. old versions asdl source fail to build with new versions of smlnj
11.4.3. old versions of smlnj not easily buildable on x8664
11.4.4. ancient binary of asdl 1.2 compiler seems to work
but associated libraries are to old to link because of missing ctype symbol
11.4.5. analyzing asdl 1.2 generated code
Most of the code is for serialization, which is going to be replaced anyway, so can be removed by hand.
11.4.6. run in vm?
Analysis of binaries shows that it was built on some redhat os using gcc 2.8.1. Redhat-6.2? No. Tried various ancient Redhat OSs.
12. Piper dovecot
12.1. Update broke dovecot auth.
Looks PAM related, but PAM update failed to fix.
12.2. Set tuffy up as a staging server
So I don't debug on 'production'.
12.3. piper dovecot SSL certificate NOT broken
At least not obviously broken (yet). Further investigation needed.
13. Various i686
13.0.1. netbsd
was installed. But needed the box for something else.
13.0.2. buildroot
builds complete.
14. piper
14.1. dovecot
14.1.1. Raising apparmor error.
Not sure how to resolve.
14.2. pidgeonhole
14.2.1. procmail replacement.
14.2.2. Considering integration.
14.3. httpd
14.3.1. Still stable.
But seems to occassionally mis-serve files.
14.4. SSL cert
Trying letsencrypt with certbot. http problem above may be interfering.
14.5. redmine
Still not sure I want to go down this rabbit hole.
14.6. openvpn
Need to consider cert construction.
15. Buffalo WZR-HP-G300NH
15.1. Update
Sometime next year.
16. SJC weather station
16.1. Proper enclosure mostly constructed
16.1.1. Needs a redo on bottom plate
16.1.2. Seems to have improved wireless connectivity somewhat
17. opencl
17.1. Studying. Have some examples working.
17.2. Need to look at arrayfire as an alternative.
17.3. This is a bit of a hammer looking for a nail.
18. EPLDH
18.1. MPFI interval arithmetic better alternative
19. wktpqb
19.1. needs a new approach
19.2. Verifying edge construction (con't.)
19.3. 'gcd' algorithm doesn't work
20. Mill Controller #2
20.1. Mounted on mill - ready or testing
20.2. Need to investigate new HW/SW for eventual replacements
20.2.1. Old crap ain't gonna last forever
20.2.2. Buildroot/Linux 5.15 PREEMPT + latency tools
First pass done - boots on real hardware
20.3. Alternative architecture
20.3.1. Split off stepper motor controller to separate board
Increase latency tolerance on controller
20.3.2. Use emc2 MODBUS/TCP protocol for stepper and other IO
21. Alum Rock Data Center
21.1. May have problem with network power module.
It's only 30 years old or something like that.
21.2. Added Ethernet card to tuffy
Preparing as backup/staging server.
21.3. Need a VPS with static IP
Just use dynamic interface to bind.
22. Virtual Orchestra
22.1. sfz file tests
22.1.1. need tooling to edit sample files
22.2. increasingly skeptical whether quality results are possible
22.3. maybe should treat as platform for concatinative synthesis
22.4. maybe should just accept the limitations and work with it
One should not be disappointed that a guitar can't sound like a flute.
23. gat
23.1. spectrogram done - matches 'octave' output
24. RIOT drivers
Implemented - needs testing.
24.1. WS2801
24.2. Velleman KA03
24.3. Velleman KA05
25. mcd05 32 button/led box
25.1. Recovered schematics.
25.2. Planning software.
25.3. Received STM32F767 Nucleo144 with Ethernet.
25.3.1. Test program running.
25.3.2. Need to consider CoAP multicast discovery.
25.3.3. Consider simpler architecture with STM32F767 as a 'hub'.
25.3.4. Consider CAN interface to hub.
26. AMD 2900 bitslice computing
26.1. Probably my oldest uncompleted project
26.2. Exploring possibilities for something constructive
Create verilog models for 2903/2910 and verify against hardware?
27. Hitachi HD68B09E CPU
27.1. RAM/UART/IO
27.2. Started schematic
27.2.1. Standard peripheral set for 8 bit CPU bringups
Board schematic planned - need Kicad symbols
27.3. Arduino Mega 2560 DMA loader
…Along with standard 8 bit loader
27.4. Generate quadrature clock directly
27.5. Full Bus SW Emulation infeasible
6809 1000ns maximum cycle time too short
28. Rockwell R65F11
28.1. Still evaluating.
28.2. Dev board
Reverse engineered some of a mostly fully built development board with one part missing. As near as I can tell, that one part is some sort of programmable address decoder with a pinout that does not correspond to any part I can find. Kind of like a GAL but with inputs on top and outputs on bottom (as opposed to left and right in a standard GAL). I have no idea what the provenance of this board is and if it ever worked.
29. PLD programming
Looks like Atmel 16V8 is the last 5V PLD part left standing. Maybe not surprising that there still doesn't appear to be a fully open source tool chain for programming. How hard could it be? (!) Could next-pnr generic help? Might be easier to use espresso for logic array and program output logic bits directly for simple stuff.
30. EPROM Programming
Found some software for Needham programmer. Need to check electrolytic caps on ISA board.
31. POSIT
31.1. Use POSITs for YRX?
No. Existing library is fine.
32. MAME
32.1. Subset builds in debug mode
Full debug fails - not enough disk or memory.
32.2. gs6809 serial IO doesn't work right with PTY and other streams
32.3. ampro (Z80/Z80SIO) does work with PTY
32.4. Evaluating what is needed for other emulators.
33. More project ideas
33.1. Zuse Z3 simulation in Verilog
Good excuse for floating point ALU design. Try posit format?
33.2. GMPForth ports to simulators
33.2.1. SIMH for some targets (vax)
33.2.2. MAME looks interesting for microprocessor system emulations
How to support ersatz systems?
33.2.3. Ports to classic figFORTH targets
33.3. GMPASM assembler
May be useful for handbuilt and rare systems (DMX1000?).
33.4. Extracting ISO Superboard Forth ROMS for MAME emulation
33.5. 'bwocl' OpenCL tooling
33.5.1. Offline compilation
33.5.2. Standard Kernel Running
33.6. hardware support for classic 5V CPUs
33.6.1. RTX2000, CDP1802 still available!
33.6.2. 6502, 68000, 320C30, others on hand
33.6.3. CPUs with totally async bus may be supportable without RAM
33.6.4. Could use small footprint monitor in asm (gmpmon?)
33.7. Existing 'retro' hardware still working?
33.7.1. OSI Superboard
Unknown. Composite to VGA adapter didn't seem to work. Needs analysis. Found OSI model 610 board underneath!
33.7.2. Super Jolt
No output. Needs analysis.
33.7.3. Ampro Little Board
Not booting. Needs analysis.
33.7.4. Rockwell R65F11 Demo board
UART sending "NO ROM" at 2400 7N1 as expected with 2MHz xtal. MAME emulator possibilities?
33.7.5. NMIX-0016
Works. Found original prom in a parts stash(!).