Masanori Ogino omasanori

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

How to flash coreboot to the thinkpad x60 the proper way

-> https://blog.aheymans.xyz/old-how-to-flash-coreboot-to-the-thinkpad-x60-the-proper-way/ is more up to date

What is so special about the x60 when running vendor bios?

Vendor BIOS write protects its bootblock, which means the lowest 64K of the flash can't be modified

This is a problem since the first code that runs on the CPU comes from there and if we ever want to run coreboot the cpu must start with coreboot code. This write protection is set in the PBR (protect bios range) registers on the southbridge, there is currently no known way to change them back once they are locked by setting the SPI Configuration Lock-Down bit.

Replacing the CenturyLink provided ethernet router with OpenBSD

Unfortunately CenturyLink provisions their fiber to the home with a PPPoE authentication over vlan 201, this makes replacing the router more difficult than it should be. I also had to call CenturyLink support to get the password for the PPPoE connection.

cnmac0 is the egress interface on my EdgeRouter Lite.

You also need to add match on pppoe0 scrub (max-mss 1452)

Installation of NixOS with encrypted root

These are my notes on instaling NixOS 16.03 on a Lenovo ThinkPad X1 Carbon (4th generation) with an encrypted root file system using UEFI.

Most of this is scrambled from the following pages:

Concurrency primitives

Signature

(* raw continuation *)
type ('a,'b) stack
perform  : 'a eff -> 'a
resume   : ('a,'b) stack -> ('c -> 'a) -> 'c -> 'b
delegate : 'a eff -> ('a,'b) stack -> 'b

WebRTC コトハジメ

更新:	2024-05-20
作者:	@voluntas
バージョン:	2024.1
URL:	https://voluntas.github.io/

Connecting to serial port (com port) over network

(Serial port or com port? - Serial ports are often refered as COM ports. It is the same to be short. You can read abut it in the Wiki article )

The problem
The solution in theory
WINDOWS
- Server
- Client

Driver Signature

	#!/usr/bin/env bash
	#
	# Author: Markus (MawKKe) [email protected]
	# Date: 2018-03-19
	#
	#
	# What?
	#
	# Linux dm-crypt + dm-integrity + dm-raid (RAID1)
	#

	#! /usr/bin/perl
	#
	# Written in 2017 by Kazuho Oku
	#
	# To the extent possible under law, the author(s) have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide. This software is distributed without any warranty.
	# You should have received a copy of the CC0 Public Domain Dedication along with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
	#
	use strict;
	use warnings;

	ssid
	xfinitywifi
	linksys
	<no ssid>
	BTWiFi-with-FON
	NETGEAR
	Ziggo
	dlink
	BTWifi-X
	default