Hacker News: ruik

Front-Panel Booting an ATmega88 Microcontroller [video]

ruik — Thu, 30 Oct 2025 13:28:45 +0000

Article URL: https://www.youtube.com/watch?v=S-2adBkW7Xo

Comments URL: https://news.ycombinator.com/item?id=45759826

Points: 3

# Comments: 0

Running Microsoft's first product on the Altair 8800, from paper tape [video]

ruik — Thu, 20 Feb 2025 19:36:01 +0000

Article URL: https://www.youtube.com/watch?v=TxU_3dEJ2nM

Comments URL: https://news.ycombinator.com/item?id=43119115

Points: 3

# Comments: 0

38C3: Illegal Instructions Streaming

ruik — Fri, 27 Dec 2024 09:39:03 +0000

Article URL: https://streaming.media.ccc.de/38c3

Comments URL: https://news.ycombinator.com/item?id=42521015

Points: 18

# Comments: 1

New comment by ruik in "38. Chaos Communication Congress Schedule"

ruik — Fri, 13 Dec 2024 15:15:56 +0000

Maybe better link https://fahrplan.events.ccc.de/congress/2024/fahrplan/schedu...

38. Chaos Communication Congress Schedule

ruik — Fri, 13 Dec 2024 09:01:56 +0000

Article URL: https://events.ccc.de/congress/2024/hub/en/schedule

Comments URL: https://news.ycombinator.com/item?id=42407049

Points: 3

# Comments: 1

I nerd sniped myself with x86 Message Signaled Interrupts format

ruik — Sun, 08 Dec 2024 20:59:05 +0000

I need your help! There seems to be some historical use of bit 11 of MSI data to be defined as "Delivery Mode" just a copy of bit 2 of MSI address, which is documented for "Delivery Mode" in the Intel SDM. Why there is a copy in message data and what for? I don't know. The earliest document I could find which mentions that is ICH2-M datasheet 290687-002 see page 5-58 and 5-59. I think this seems to be documented up to ICH10. Maybe it is connected to Itanium somehow (but it does not support logical delivery?!) Sometimes there is a note that chipset clears that bit when sent to CPU. Seems like Linux kernel in x86 msi.h has "dest_mode_logical" fields for both address/data fields, but never uses that. I think I seen Windows to set it, when examining MSI data/address pairs. Oh and there is a lot of fun with RH bit and DM bit combinations which SDM is contradicting to itself - likely also due to the Itanium compatibility. Lastly, on AMD the format of MSI/address/data is undocumented, but funnily for NMI encoding, you have to use hypertransport encoding and not intel encoding to trigger NMI on AMDs. This rabbit hole is very deep! Where to document it once we know everything?

Comments URL: https://news.ycombinator.com/item?id=42360380

Points: 1

# Comments: 0

Making 8-bit Music From Scratch at the Commodore 64 BASIC Prompt [video]

ruik — Tue, 19 Nov 2024 20:17:08 +0000

Article URL: https://www.youtube.com/watch?v=ly5BhGOt2vE

Comments URL: https://news.ycombinator.com/item?id=42187632

Points: 8

# Comments: 1

Never Gonna Gifugue Up [video]

ruik — Sun, 15 Sep 2024 19:46:16 +0000

Article URL: https://www.youtube.com/watch?v=tlV0k-rC-00

Comments URL: https://news.ycombinator.com/item?id=41549797

Points: 7

# Comments: 0

DEF Con 32 – AMD Sinkclose Universal Ring-2 Privilege Escalation (Not Redacted) [pdf]

ruik — Sat, 07 Sep 2024 19:44:07 +0000

Article URL: https://media.defcon.org/DEF%20CON%2032/DEF%20CON%2032%20presentations/DEF%20CON%2032%20-%20Enrique%20Nissim%20Krzysztof%20Okupski%20-%20AMD%20Sinkclose%20Universal%20Ring-2%20Privilege%20Escalation.pdf

Comments URL: https://news.ycombinator.com/item?id=41475975

Points: 195

# Comments: 30

GhostWrite Bug of XuanTie C910 and C920 RISC-V CPU

ruik — Fri, 09 Aug 2024 16:30:40 +0000

Article URL: https://ghostwriteattack.com

Comments URL: https://news.ycombinator.com/item?id=41203327

Points: 1

# Comments: 0

Can a Steel Cutting Laser Cook a Perfect Burger? [video]

ruik — Fri, 23 Feb 2024 18:57:08 +0000

Article URL: https://www.youtube.com/watch?v=9VmITd0dKAo

Comments URL: https://news.ycombinator.com/item?id=39484713

Points: 9

# Comments: 2

New comment by ruik in "Minimal Linux Bootloader debugging story"

ruik — Sun, 11 Feb 2024 20:37:16 +0000

That blast from the past and welcome to the 80's ! The 0x87 BIOS service is used to perform the memcpy() from real mode. You might think it is just 3 arguments! But not in that good old days of 1987++ it was all much more convoluted fun! The API has so strange format because it tells you to construct two segment descriptor entries including correct segment attributes. The structure of that buffer is a hack that allows BIOS to create more entries internally (SS/CS? descriptors likely) and use whole buffer as a new GDT which will be used for a copy in protected mode stub. So your destination on SI+0x18 and source SI+0x10 are in fact two GDT entries which BIOS will just use for REP MOVSD/MOVSW. And because you are on 386+ CPU, yes you can use full 32-bit address (in SI+0x17/SI+0x1E) If you are wondering about the detailed format, check data segment descriptor format in AMD or Intel documentation. The max size to copy in CX reg is 0x8000*2 bytes, but this is likely due to the 80286 segment limit which was 64K. It may just work on 386 with 128K, but I would not count on it. Keep the SI+0x16/SI+0x1D zero -> Don't touch D/B bit nor the G bits. You can consult Ralf's brown interrupt list for further details about this INT 0x15 AH=0x87 call. Rudolf