10-10 update

index.wiki

@@ -21,7 +21,10 @@ _Ideas.md and Classes.md are encrypted, so these links will not work_
 * [[tech/databases|Databases & SQL]] - Databases and SQL
 * [[tech/os|Operating Systems Design]] - Basic building blocks of an OS
 * [[tech/embedded|Embedded Programming]] - Embedded Systems like arduinos and (kinda) pi's
-* [[electronics|Digital and Analog]] - Digital and analog electronics
+* [[tech/electronics|Digital and Analog]] - Digital and analog electronics
+* [[tech/unix|Unix]] - Gentoo and other unix systems
+* [[tech/3D_printing|3D Printing]] - Print objects from plastic
+* [[tech/android|Android]]
 * [[tech/misc|Misc]] - Miscellaneous tools
 
 == [[lang/index|Languages]] ==
@@ -44,6 +47,7 @@ _Ideas.md and Classes.md are encrypted, so these links will not work_
 * [[sci/chemistry|Chemistry]]
 * [[sci/physics|Physics]]
 * [[sci/biology|Biology]]
+* [[sci/chemicals/index|Chemicals]]
 
 == [[botany/index|Botany]] ==
 
@@ -51,6 +55,8 @@ _Ideas.md and Classes.md are encrypted, so these links will not work_
 * [[botany/hydroponics|Hydroponics]]
 * [[botany/aquaponics|Aquaponics]]
 
+== Cooking ==
+
 == Local to GentooBox ==
 
 === School ===

lang/Bash.wiki

@@ -98,4 +98,20 @@ ${FOO//from/to} #replace all instances of from with to
 ${#FOO} #length of foo
   }}}
   
+== Common tasks ==
+
+Rename push all .png files through convert
+
+{{{
+for file in *.png; do
+    convert $$file "$${file%.png}.eps"
+done
+  }}}
+
+
+
+
+
+
+  
 [[index]]

lang/C.wiki

@@ -6,6 +6,16 @@ Systems language. One of the fastest langs around
 
 * [[bithacks]] - Wacky was to break memory
 
+== stdlib ==
+
+standard library functions
+
+* man atoi
+ - string to int
+* man strtol
+ - string to long
+* man fgets
+ - get string from file
 
 == Also See ==
 

lang/Python.wiki

@@ -0,0 +1,13 @@
+= Python =
+
+Wonderful little scripting language
+
+== Libraries ==
+
+== Built ins ==
+
+=== Map ===
+
+takes a function (can be a lambda) and an iterator to perform the function upon
+
+[[index]]

lang/index.wiki

@@ -14,7 +14,10 @@
 * [[Rust|Rust]]
 * [[Go|Go]]
 * [[sql|SQL]]
+* [[x86|x86]]
 
+== Also see ==
 
+* [[../tech/index]]
 
 [[../index]]

sci/acids.wiki

@@ -1,7 +1,8 @@
 = Acids =
 
 Any substance that releases H^+ ion in aqueous [[solution]], aka H is first in
-chemical formula
+chemical formula.
+Hydrogen released by acids are called hydronium ions
 
 * HCL
 * HCL + H,,2,,O => H,,3,,O^+ + Cl^-
@@ -9,8 +10,24 @@ chemical formula
 == Common Acids ==
 
 * HF,,(g),, - hydrogen fluoride
-* HF,,(aq),, - hydofluoric acid
+* HF,,(aq),, - hydrofluoric acid
 * HCl,,(g),, - hydrogen chloride
-* HCl,,(aq),, - hydrocloric acid
+* HCl,,(aq),, - hydrochloric acid
+* citric acid
+* ascorbic acid
+* lactic acid
+
+== Common characteristics ==
+
+* Taste sour
+* turn litmus paper red
+* react with metal to release hydrogen
+
+== Also see ==
+
+* [[bases]]
+* [[salts]]
+* [[pH]]
+* [[bronsted-lowry]]
 
 [[index]]

sci/bases.wiki

@@ -1,7 +1,25 @@
 = Bases =
 
 Any substance that releases OH^- ion in aqueous solution, *bonds with a metal*
+The OH is referred to as hydroxide ion
 
 * NaOH + H,,2,,O => Na^+ OH^-
 
+== Common bases ==
+
+* NaOH (lye)
+* Ammonia (NH,,3,,)
+
+== Common Characteristics ==
+
+* Taste bitter
+* turn litmus paper blue and feel slippery
+
+== Also see ==
+
+* [[acids]]
+* [[salts]]
+* [[pH]]
+* [[bronsted-lowry]]
+
 [[index]]

sci/bronsted-lowry.wiki

@@ -0,0 +1,25 @@
+= Bronsted-Lowry =
+
+A definitions of acids and bases that describes an acid as a compound that is
+capable of donating a proton (H+) to form the hydronium ion (H,,3O^+) in aq
+solution. Weak acids are partially ionized
+
+== How to identify ==
+
+* Strong Acid
+ - All solute it ionized
+ - One of the ions is hydronium
+* Weak Acid
+ - Some of solute is ionized
+ - One of the ions is hydronium
+* Non acid
+ - Any amount is ionized
+ - No hydronium is formed
+
+== Also see ==
+
+* [[acids]]
+* [[salts]]
+* [[pH]]
+
+[[index]]

sci/chemicals/NCl3.wiki

@@ -0,0 +1,13 @@
+= NCL3 =
+
+Nitrogen tri-chloride, one of the most finicky explosives, aka touch powder.
+
+NOTE reacts with plastic, be sure to use teflon paper
+
+== How to make ==
+
+Requires an oxidizing source of chlorine, and source of nitorgen like Urea
+
+Can be made using [[TCCA]] and [[amonia]]
+
+[[index]]

sci/chemicals/index.wiki

@@ -0,0 +1,14 @@
+= Chemicals =
+
+A list of chemicals that are interseting
+
+== General ==
+
+* [[peroxide]]
+
+== Dangerous ==
+
+* [[NCl3]]
+
+
+[[../index]]

sci/chemicals/peroxide.wiki

@@ -0,0 +1,6 @@
+= Peroxide =
+
+A peroxide is any chemical in which two oxygen atoms are linked together by a
+single covalent bond. 
+
+[[index]]

sci/chemistry.wiki

@@ -10,5 +10,4 @@ Took chemistry I Fall 2021. These are those notes
 * [[reactions|Reactions]]
 
 
-
 [[index]]

sci/electrolytes.wiki

@@ -0,0 +1,29 @@
+= Electrolytes =
+ 
+* Electrolytes
+ - Any substance that conducts electricity when disolved into water
+* Non-electrolytes
+ - Any substance that does not conduct when dissolved in water
+
+If ions are not formed, the compound is not an electrolyte. 
+
+* [[salts]]
+ - MetalAnion = Metal^+ + Anion^-
+* [[acids]]
+ - HAnion = H + Anion^-
+* [[bases]]
+ - MOH = Metal + OH^-
+
+== Strong and weak electrolytes ==
+
+* Most salts of alkali and alkali earth metals are strong electrolytes
+* Most acids are weak electrolytes
+* Hydroxides (OH) of alkali metals are strong [[bases]]
+* Molecular substances (non metals bounded with non-metals) are
+  non-electrolytes
+
+== Also see ==
+
+[[solution]]
+
+[[index]]

sci/index.wiki

@@ -6,6 +6,8 @@ Notes on how all of it works, from school or from simulating it
 
 * [[chemistry|Chemistry]]
 * [[physics|Physics]]
+* [[biology|Biology]]
+* [[chemicals/index|Chemicals]]
 
 
 [[../index]]

sci/ionic_equations.wiki

@@ -0,0 +1,24 @@
+= Ionic Equations =
+
+Chemical equations that show each substance as it exists in a [[solution]]
+
+* Unionized equation
+ - Compounds in the equation are written in molecular or normal form
+* Total ionic equation
+ - Compounds written in ionic form or true form in solution
+* Net ionic equation
+ - Only the species that are involed in the reaction are shown
+* Spectator ions
+ - Ions not directly involved in the reaction, yet are still present
+
+== Rules for writing euqations ==
+
+1) Ionic compounds (acids bases and salts) that are shown as (aq) are written
+   in ionic form
+2) Covalent compunds are free eleemnts are never written in ionic form
+3) Net ionic equations only show substances undergoing change
+4) Equations must be balanced
+
+== Also see ==
+
+[[solution]]

sci/naming.wiki

@@ -31,5 +31,26 @@ Naming compounds of ions
 * Name = cation + anion
  - MgO = magnesium oxide
  - Fe,,2,,(CO,,3,,),,3,, = iron(III)carbonate ferric carbonate
-  
+
+== Naming acids ==
+
+See [[acids]]
+
+* Named based on anion attached to the hydrogen
+* When binary acid (one ion with hydrogen)
+ - Prefix -hydro
+ - first syllable of anion
+ - suffic -ic
+* Complex acids have Oxygen in them
+* Acid with polyatomic ion (OH), (NO,,3,,)
+ - replace -ate with -ic
+* Polyatomic with one extra oxygen (compared to typical polyatomic ion)
+ - prefix per-
+ - suffic -ic
+* Polyatomic ions with one fewer oxygen (compared to typical)
+ - suffix -ous
+* Polyatmoic ions with two fewer oxygen
+ - prefix hypo-
+ - suffix -ous
+
 [[index]]

sci/pH.wiki

@@ -0,0 +1,8 @@
+= pH =
+
+Measure how basic or acidic solution is, based on number of H,,3,,O on
+logarithmic scale. 
+
+Values range from 0 to 14
+
+pH = -log(H,,3,,O)

sci/reactions.wiki

@@ -2,4 +2,18 @@
 
 The interaction between 2+ substances
 
+== [[solution|Solutions]] ==
+
+A substance suspended in another (usually water)
+
+see [[solution|Solutions]] 
+
+== [[electrolytes|Electrolytes]] ==
+
+see [[electrolytes|Electrolytes]] 
+
+== Ionic Equations ==
+
+see [[ionic_equations|Ionic Equations]]
+
 [[index]]

sci/salts.wiki

@@ -6,4 +6,10 @@ To neutralize is to react and acid and base
 
 * HCl,,(aq),, + NaOH => NaCl + H,,2,,O
 
+== Also see ==
+
+* [[bases]]
+* [[salts]]
+* [[pH]]
+
 [[index]]

sci/solution.wiki

@@ -9,6 +9,15 @@ A substance suspended in a liquid
 
 When suspended, molecule is surrounded by solvent
 
+* Saturated
+ - A solution containing the max amount of dissolved solute at a given temp
+* Unsaturated
+ - A solution containing less than the max amount of dissolved solute at a
+   given temp
+* Supersaturated
+ - Solution containing more than the max amount of dissolved solute at given
+   temp. In a non equilibrium situation.
+
 == Measuring ==
 
 Molarity is moles_solute/liters_solution
@@ -17,4 +26,86 @@ This is a ratio
 
 Dilution reduces this ratio
 
+== Dissolution Process ==
+
+When a solute dissolved into a solvent
+
+Can be interaction of any two states of matter (except plasma)
+
+* Solute-Solute
+ - interactions are broken
+ - Endothermic
+* Solvent-Solvent
+ - interactions are broken
+ - Endothermic
+* Solvent-Solute
+ - interactions are formed
+ - exothermic
+
+The oposite charge of the water molecule pulls molecules of other molecules off
+of structure and into the solution. Works with ionic compounds ie NaCl
+
+== Solubility ==
+
+A quantitative term that describes the max amount of a substance that will
+dissolve in a given amount of solvent. Usually in g/100mL
+
+* sucrose
+ - 204g/100mL
+* AgCl
+ - 9 x 10^-5 g/100mL
+
+* Micsible
+ - Liquids that are mutuall soluble in all proportions
+* Immiscible
+ - Liquids that are mutually insoluble
+
+Nature of solute and solvent, ie _likes disolve likes_
+
+Temperature increases in solids/liquids means incresed solubility, due to
+increase in solute-solvent interactions
+
+For gasses the opposite is true. For gasses, as pressure increases, so does
+solubility. *Henry's Law*
+
+=== Guidlines for water ===
+
+* Compounds with Group I ions (NH,,4,, , NO,,3,,) are *always soluble in water*
+* Compounds containing 
+ - Cl, Br, I
+  - Unless in soln with Ag, Cu, Hg^2 and Pb^2
+ - SO,,4,,^2 
+  - Unless in soln with Ba Ca Hg^2 Pb^2 and Sr^2
+
+^ Above are always soluble in water
+
+Insoluble
+
+* OH^-
+ - Except with Alkali metals and ammonium
+* S^2-
+ - Except with Barium, strontium, magnesium, sodium, potasium, and ammonium
+* Carbonates, oxalates, chromates, and phostates
+ - Except with Alkali metals and ammonium
+
+== Hydrates ==
+
+Compounds that have water molecules imbedded into their structure. Amount of
+water is inidicated with latin prefixes. 
+
+Named via prefix + hydrate
+
+== Concentration ==
+
+* Concentration
+ - A quantitative expression of the amount of solute dissolved into a solvent
+* Concentrated solution
+ - A solution of high concentration
+* Dilute solution
+ - Solution of low concentration
+
+== [[electrolytes|Electrolytes]] ==
+
+see [[electrolytes|Electrolytes]] 
+
 [[index]]

tech/3D_printing.wiki

@@ -0,0 +1,6 @@
+= 3D Printing =
+
+3D printers can make stuff from raw spools of plastic
+
+
+[[index]]

tech/K-map.wiki

@@ -0,0 +1,7 @@
+= K-map =
+
+K-maps are ways of simplifying boolean expressions.
+
+They are usually created from the sum of min values, graphed out into a grid
+
+[[index]]

tech/algorithms.wiki

@@ -39,5 +39,12 @@ Different ways to store and operate on data, with differing efficiency
 * [[greedy_algorithm|Greedy Algorithms]]
 * [[brute_force|Brute Force]]
 * [[randomized_algorithm|Randomized Algorithms]]
+* [[genetic|Genetic Algorithms]]
+* [[swarm|Swarm Inteligence]]
+* [[neural|Neural Networks]]
+
+== Common operations ==
+
+* [[gcd]] - Find the GCD of two numbers
 
 [[index]]

tech/android.wiki

@@ -0,0 +1,23 @@
+= Android =
+
+A mobile operating system for phones and tablets
+
+== Tools ==
+
+* adb
+
+== Tasks ==
+
+=== Data recovery ===
+
+How to get the data off of an android phone
+
+1) Have adb installed on the host system
+2) Have MTF installed on the host system
+3) Enable USB Debugging on the device
+4) adb devices
+ - Keep changing the USB mode till the device shows up in the list that is
+   shown
+5) adb shell
+ - This drops you into a bash-like shell on the device
+6) 

tech/arduino_nano.wiki

@@ -11,12 +11,14 @@ see [[arduino_techniques|Programming Techniques]]
 * 2Kbytes SRAM 
 * 32Kbytes flash
 * 1Kbytes EEPROM
-* Three on board LED's
+* Three on board LED's * 20 IO pins
-* 20 IO pins
 * 6 PWM and 6 ADC
 
 == Notes ==
 
+* WHEN UPLOADING BE SURE TO SET BOARD TO ATMEGA328OLD
+ - this is the atmega328old for BOARD_SUB in the makefile
+
 === Memory ===
 
 * AVR instructions are 16 or 32bits wide, therefore the flash is 16K x 16
@@ -36,6 +38,11 @@ see [[arduino_techniques|Programming Techniques]]
 
 === Pins ===
 
+Pins are controller by the atmega's ports. Each port has different port
+registers. Each bit of the 8 bit register controls a single pin. Port D
+controls pins 0 through 7, C controls the analog pins, and B controls 8 through
+13
+
 * PortC
   - Port C data regiser
   - 0x28
@@ -65,4 +72,9 @@ Same pattern:
 * PortD
   - 0x2B - 0x29
 
+=== Interrupts ===
+
+Interrupts are the same as OS typical interrupts, controlled by the Interrupt
+lookup table. On this device the ILT is instead a control register. 
+
 [[embedded]]

tech/binary_tree.wiki

@@ -0,0 +1,24 @@
+= Binary tree =
+
+A branching data structure that is pointer heaven. Traversal is very fun
+
+== Good For ==
+
+* Finding data in log(n) time
+* Organizing tiered data
+
+== Bad For ==
+
+* Cache Hits
+
+== Common operations ==
+
+=== Level Order Traversal ===
+
+To traverse a tree level by level it requires a queue to keep track of what is
+next to traverse. To do this we first push the all child nodes onto the queue.
+We then visit each element in the node and push on its children into the queue.
+We do this for every element till we have no elements in the queue. When this
+happens, we have traversed the entire tree level by level.
+
+[[algorithms]]

tech/cross_toolchain.wiki

@@ -0,0 +1,46 @@
+= Cross Toolchain =
+
+Setting up the tool chain involves getting a compiler for a different
+architechure compiled on your machine. With gentoo its pretty straight forward,
+and thats what this are instructions for. This example uses avr, but can be
+subsititued for arm if needbe
+
+== Cross-compiler toolchain ==
+
+Here is how to get the cross compiler toolchain setup, at least on gentoo
+
+1) emerge sys-devel/crossdev
+  - Gentoo package for crossdev tools
+2) mkdir -p /var/db/repos/portage-crossdev/{profiles,metadata} && echo 'crossdev'
+   > /var/db/repos/portage-crossdev/profiles/repo_name && echo 'masters =
+   gentoo' > /var/db/repos/portage-crossdev/metadata/layout.conf && chown -R
+   portage:portage /var/db/repos/portage-crossdev
+  - All of this sets up a local portage repo, for compiling tools for other
+    systems
+3) have portage and crossdev use this new repo \
+   {{{
+   #/etc/portage/repos.conf/crossdev.conf
+   [crossdev]
+   location = /var/db/repos/portage-crossdev
+   priority = 10
+   masters = gentoo
+   auto-sync = no
+     }}}
+  - This tells portage about crossdev and that packages can be in it, but not
+    to try and update them with out our permission
+4) Add the following to a new file
+   {{{
+   #/etc/portage/profile/package.use.force/avr-STRING_HERE
+   cross-avr/gcc -pie -pic
+     }}}
+5) crossdev -s4 --stable --portage --verbose --target avr
+  - s4 means to build everything from binutils to a full compiler
+  - stable means to use latest stable versions
+  - portage tells what flas to pass to emerge
+  - target specifies our target, the avr arch. 
+  - *For arm specificy arm, this also includes other things like pis*
+6) If any errors are thrown, follow them and try again. Common errors include
+  - make package.mask a directory
+
+
+[[index]]

tech/development.wiki

@@ -7,13 +7,13 @@
 * [[libcurl|Libcurl]] - Curl the tool, but the API
 * [[periodictable|Periodic Table]] - Python periodic table
 
-
 == Tools ==
 
 * [[gcc|GCC]] - Gnu compiler
 * [[cgdb]] - Vim like front end for the GNU Debugger
 * [[make|Make]] - Automate compiling
 * [[vim]] - Text editor
+* [[qemu]] - Virtual machine
 
 
 

tech/electronics.wiki

@@ -3,13 +3,19 @@
 Both digital and analog components
 
 
-= Combinational =
+== Combinational ==
 
 * [[multiplexer|Multiplexer]]
 
 
-= Sequential =
+== Sequential ==
 
 * [[buffer|Buffer]]
 
+== Theoretical ==
+
+* [[K-map]]
+
+
+
 [[index]]

tech/embedded.wiki

@@ -8,17 +8,26 @@ user, sometimes so that they don't even know there is a computer
 * https://www.microchip.com/en-us/product/ATmega328
 * [[RISC]] Processor type
 
+== Raspberry pi ==
+
+* https://datasheets.raspberrypi.org/rpi4/raspberry-pi-4-datasheet.pdf
+  - Pi 4 Model B
+* https://datasheets.raspberrypi.org/pico/pico-datasheet.pdf
+  - Pi Pico
+* [[ARM]] Processor type
+
 === Line of products ===
 
 * [[arduino_nano|Arduino Nano]]
 * [[arduino_uno|Arduino Uno]]
-
+* [[raspberry_pi|Raspberry Pi]]
+* [[rapsberry_pi_pico|Raspberry Pi Pico]]
 
 === Programming ===
 
 * [[../lang/C|C]]
 * [[../lang/C++|C++]]
 * [[arduino_techniques|Techniques]]
-
+* [[cross_toolchain|Arduino Cross-Toolchain setup]]
 
 [[index]]

tech/ffmpeg.wiki

@@ -0,0 +1,22 @@
+= FFmpeg =
+
+Command line tool for working with video
+This is just a collection of common tasks
+
+== Rencode as another video ==
+
+{{{
+ffmpeg -i in.mkv out.mp4
+  }}}
+
+== Export clip from video ==
+
+This will grab a clip starting at 30s that lasts for 10s
+
+All timestamps must be of format HH:MM:SS.xxx
+
+{{{
+ffmpeg -i in.mp4 -ss 00:00:30.0 -c copy -t 00:00:10.0 out.mp4
+  }}}
+
+[[index]]

tech/gcd.wiki

@@ -0,0 +1,16 @@
+= GCD =
+
+Greatest common divisor is the multiple that two numbers have in common
+
+== Extended Euclidean's Algorihtm ==
+
+Way to find the greatest common divisor of two numbers
+
+* Theorm
+ - If m,n are relatively prime then n has an inverse mod m
+  * n^-1 = b mod m
+ - Where a,b are any integer solutions to 
+  * a * m = b * n = 1 mod m
+ - and b would be a modular inverse of n
+ 
+ [[index]]

tech/gentoo_cheat_sheet.wiki

@@ -0,0 +1,61 @@
+= Gentoo Cheat Sheet =
+
+Some common operations you need to do to administer a gentoo machine
+
+== Sync methods ==
+
+{{{
+#sync main gentoo repo
+emerge --sync
+#sync overlays managed with layman
+layman -S
+  }}}
+
+== Managing packages ==
+
+{{{
+#install and allow to be managed by portage
+emerge www-client/firefox
+#install without adding to world file
+emerge --oneshot www-client/firefox
+
+#remove a package
+emerge --deselect www-client/firefox
+#actually clean up no longer installed packages
+emerge --depclean
+
+#update entire system
+emerge --ask --verbose --update --changed-use --deep @world
+
+#apply --autounmask changes
+dispatch-conf
+  }}}
+  
+== Troubleshooting ==
+
+{{{
+#check for missing libraries and rebuild them
+revdep-rebuild -v
+
+#check which packages depend on the given package
+#ie what does firefox depend on?
+equery d www-client/firefox
+  }}}
+
+== Use flags ==
+
+Use flags are kept in /etc/portage/package.use/
+
+== Overlays ==
+
+{{{
+#list all existing overlays
+layman -L
+#list installed overlays
+layman -l
+
+#add an overlay
+layman -a OVERLAY
+  }}}
+
+[[index]]

tech/hash_table.wiki

@@ -6,7 +6,7 @@ flavors.
 
 == Good For ==
 
-* Crazy fast [[look]] ups
+* Crazy fast look ups
 
 == Bad for ==
 

tech/imagemagick.wiki

@@ -0,0 +1,16 @@
+= Imagemagick =
+
+Tools for conveting images on the command line
+This is just a list of random stuff you can do using it
+
+== Make a gif ==
+
+{{{
+#make a gif out of images
+convert IMG.png IMG2.png ... -delay DELAY -loop 0 out.gif
+
+#make a gif that quickly changes images
+convert IMG.png IMT2.png ... -loop 1 out.gif
+  }}}
+  
+[[index]]

tech/index.wiki

@@ -10,6 +10,13 @@ Everything dealing with my awful addiction to computers
 * [[os|Operating Systems Design]] - Basic building blocks of an OS
 * [[embedded|Embedded Programming]] - Embedded Systems like arduinos and (kinda) pi's
 * [[electronics|Digital and Analog]] - Digital and analog electronics
+* [[unix|Unix]] - Gentoo and other unix systems
+* [[3D_printing|3D Printing]] - Print objects from plastic
+* [[android|Android]]
 * [[misc|Misc]] - Miscellaneous tools
 
+== Also see ==
+
+* [[../lang/index]]
+
 [[../index]]

tech/kernel.wiki

@@ -0,0 +1,85 @@
+= Linux kernel =
+
+The part actually called Linux. Some stuff on compiling for it and things it
+provides
+
+== Proc ==
+
+/proc is a virtual filesystem provided by the kernel that has info on processes
+running and some basic system info. Here are some useful things from it.
+
+* meminfo
+ - info about ram usage
+* acpi/*
+ - info about things that control power (such as laptop lid, power button, etc)
+* sys/kernel/*
+ - info about the status of the kernel
+* crypto
+ - encryption algorithms built into the kernel
+* uptime
+ - system uptime
+* fs/*
+ - all supported filesystems
+
+== Dev ==
+
+The device virtual file system, located at /dev. Each device is a file and can
+be talked to here. Here is some useful info from it
+
+* random
+ - random data
+* urandom
+ - less predictable random data
+* zero
+ - outputs nothing
+* tty*
+ - All of the different virual terminals
+* cpu/*
+ - All cpu cores 
+* snd/*
+ - All sound devices
+* usb/*
+ - USB devices
+* disk/*
+ - All available disks, can be viewed by uuid, partlabel, and more
+* mapper/*
+ - Where LVM partitions are mounted, including encrypted partitions and drives
+
+== Updating the kernel ==
+
+First be sure to mount the boot parition to /boot
+
+Next copy your .config from the source directory of your previous kernel to
+somewhere safe
+
+For gentoo, you'll need to switch your /usr/src/linux symlink using eselect now
+
+Now begins the commands
+
+1) make mrproper
+  - make clean with no additional atrtifacts
+2) cp /path/to/kernel/config .config
+  - Install old config file
+3) make olddefconfig
+  - copy over old config options to new kernel config
+4) make modules_prepare
+  - Prepare kernel modules on system
+5) make -jX
+  - make the kernel! replace X with number of desired threads
+6) make modules_install && make install
+  - install the new kernel and modules
+7) (Gentoo) emerge @module-rebuild
+  - Recompile kernel modules to work with the new kenel
+8) (Encrypted root only) genkernel --luks --lvm --kernel-config=/path/to/kernel/config initramfs
+  - If not on gentoo use distros initramfs build tool. splash adds a splash
+    screen and is not required
+9) (Optional) Clean up all kernels
+  - Go ahead and remove all references in /boot to an older kernel. DO NOT
+    delete the current kernel, you may need it in case installing this kernel
+    fails!
+10) grub-mkconfig -o /boot/grub/grub.cfg
+  - Let grub update its config to know that the new kernel exists
+11) reboot
+  - reboot and hope it worked!
+
+[[index]]

tech/ls.wiki

@@ -0,0 +1,26 @@
+= ls =
+
+List files in directory
+
+== Usage and flags ==
+
+ls [FLAGS] [FILE]
+
+* [FILE]
+ - folder/file to list contents of. defaults to current dir.
+* -a aka --all
+ - include hidden files in listing
+* --color
+ - color the output
+* -l aka --long
+ - show more info about files, like ownership, time last modified, etc
+* -d aka --directory
+ - list only directories
+* -h aka --human-readable
+ - list sizes of files in human readable format
+* -s aka -size
+ - Print sizes of each file
+
+For full usage use man ls
+
+[[index]]

tech/misc.wiki

@@ -2,4 +2,14 @@
 
 Misc. Stuff relating to computers and tech in general
 
+== Tools ==
+
+* [[imagemagick]]
+* [[ffmpeg]]
+
+== Stuff to do ==
+
+* [[wireless_usb]]
+
+
 [[index]]

tech/openrc.wiki

@@ -0,0 +1,25 @@
+= Openrc =
+
+The init system I use
+
+== Configuration ==
+
+* /etc/rc.conf
+ - global openrc config file
+* /etc/conf.d
+ - Individual config file for each script
+
+== Usage ==
+
+{{{
+#remove from a runlevel
+rc-update delete <service> default
+
+#show all init-script and their current runlevel
+rc-update show -v
+
+#show status of all services
+rc-status --servicelist
+  }}}
+  
+[[index]]

tech/os.wiki

@@ -3,8 +3,28 @@
 The primary 'program' running on a machine that allows a user to run several
 programs at once, manages drivers and hardware abstraction, etc
 
+also see [[kernel]]
+
 == CPUs ==
 
 * [[RISC]]
+* [[x86]]
+* [[ARM]]
+
+== Assembly ==
+
+* [[../lang/x86]]
+
+== Concepts ==
+
+* [[scheduler]]
+* [[microkernel]]
+* [[monolithic_kernel]]
+* [[system_calls]]
+
+== Tools ==
+
+* [[qemu]]
+* [[cross_toolchain|Cross compiler toolchain]]
 
 [[index]]

tech/pwd.wiki

@@ -0,0 +1,16 @@
+ = pwd =
+ 
+ Print the working directory
+ 
+ == Usage and Flags ==
+ 
+ pwd [-L|-P]
+ 
+* -L 
+ - print pwd that usually appears in command line status, aka LOGICAL path
+* -P
+ - ignore symlinks, aka PHYSICAL path
+
+also see man pwd
+
+[[index]]

tech/qemu.wiki

@@ -0,0 +1,49 @@
+= QEMU =
+
+QEMU is a lightweight cli virtual machine program
+
+== Making a virtual disk ==
+
+To run a vm you need a virtual hard drive. To make one,
+
+{{{
+qemu-img create -f file_format <image_name> image_size
+  }}}
+  
+File format can be raw, qcow2, etc
+
+size is notated with G for gigabytes, ie 5G is 5 gigabytes
+
+== Making a virtual machine ==
+
+We need a virtual disk and an iso file to run. To do this
+
+{{{
+qemu-system-x86_64 -cdrom iso_image -cpu host -enable-kvm -m RAM_size -smp
+number_of_core -drive file=disk_image.iso,format=qcow2
+  }}}
+  
+-cdrom is for iso_image
+
+-cpu host is to emulate the host processor
+
+-enable-kvm uses the kernel virtual machine
+
+-m is for memory, ie 2048
+
+-smp is for the number of cores, ie 4
+
+To run off of an already installed hard drive without an iso, run
+
+{{{
+qemu-system-x86_64 -cpu host -enable-kvm -m 2048 -smp 2 -drive
+file=/path/to/vdisk.qcow2,format=qcow2
+  }}}
+  
+== Emulating different systems ==
+
+If we want to emulate i386, replace 'qemu-system-x86_64' with
+'qemu-system-i386'. This works with most other architectures, assuming you have
+them installed.
+
+[[index]]

tech/rapsberry_pi_pico.wiki

@@ -0,0 +1,9 @@
+= Raspberry Pi Pico =
+
+Raspberry pi's micrcontroler, based on the RP2040
+
+* https://datasheets.raspberrypi.org/pico/pico-datasheet.pdf
+
+
+
+[[index]]

tech/raspberry_pi.wiki

@@ -0,0 +1,18 @@
+= Raspberry Pi =
+
+Mainline tiny linux computers. Cheap as hell too
+
+== Features ==
+
+* [[ARM]] processors
+* Can boot several OS's including linux
+* Usually 802.11 and bluetooth
+* 40 gpio pins
+
+== Projects ==
+
+* [[octopi]]
+* [[NAS]]
+* [[wireless_usb|Wireless USB]]
+
+[[index]]

tech/security.wiki

@@ -2,9 +2,18 @@
 
 Tools useful for security, either offensive or defensive
 
+== Cryptology ==
+
+Hiding information
+
+=== Ciphers ===
+
+* [[substitution|Substitution]] 
+
 == Reconnaissance ==
 
 * [[nmap|nmap]] - port scanner
+* [[masscan]]
 
 
 

tech/substitution.wiki

@@ -0,0 +1,43 @@
+= Substitution =
+
+A Cipher where characters are replaced based on a mapping
+
+== Monoalphabetic Subsititutions ==
+
+Cipher where each occurrence of a plaintext symbol is replaced by a
+corresponding ciphertext symbol
+
+=== Afline ===
+
+An affine cipher E(x) = (ax + b) MOD 26 is a monoalphabetic sub cipher, where a
+and b are given constants
+
+=== Columnar Transposition ===
+
+Use letters to create columns, then fill all remaining columns with remaining
+letters in alphabetic order
+
+
+
+
+== Cryptoanalysis ==
+
+=== Monoalphabetic Substitution ===
+
+We make some assumptions
+
+* Its english and has same stats as standard english
+* word divisions are not preserved
+* use frequency analysis to guess high frequency letters
+  - E E N O R I A S are 70% of letters in english
+* identify 
+ - vowels
+ - diagraphs (common combos of letters ie TH)
+* Use cribs
+* guess and rely on luck
+
+== Also see ==
+
+* [[gcd]]
+
+[[index]]

tech/tar.wiki

@@ -0,0 +1,18 @@
+= Tar =
+
+Make tar balls and compress them
+
+== Compress a folder ==
+
+{{{
+tar -czvf outfile.tar.gz /dir/to/compress
+  }}}
+  
+== Open a tar ball ==
+
+{{{
+tar -xzvf /path/to/tar/ball.tar.gz
+  }}}
+
+
+[[index]]

tech/unix.wiki

@@ -0,0 +1,32 @@
+= Unix =
+
+The bell labs proposal for the best OS design ever
+
+== Standard Utilities ==
+
+* [[../lang/Bash]]
+* [[ls]]
+* [[cd]]
+* [[pwd]]
+* [[grep]]
+* [[awk]]
+* [[sed]]
+* [[sort]]
+* [[uniq]]
+* [[shuf]]
+* [[tar]]
+
+== Gentoo ==
+
+* [[gentoo_cheat_sheet|Gentoo Cheat Sheet]]
+* [[openrc|Openrc]]
+* [[kernel|Kernel updates and configuration]]
+ - [[kernel#Updating the kernel]] - Steps to update the kernel
+* [[cross_toolchain|Cross toolchain]] - Setting up a cross compiling toolchain
+
+
+== Cool stuff ==
+
+* [[wireless_usb]]
+
+[[index]]

tech/vim.wiki

@@ -0,0 +1,36 @@
+= Vim =
+
+This text editor, most likely unless you're on the website
+
+== To use ==
+
+run
+
+{{{
+:h vim
+  }}}
+  
+== Useful things ==  
+
+=== Dos to Unix line endings ===
+
+To save the current file with different line endings, run
+
+{{{
+:w ++ff=unix
+:w ++ff=mac
+:w ++ff=dos
+  }}}
+  
+Replace w with e to replace the line endings in the editor
+
+=== Search and replace ===
+
+This will replace all instances of FOO with BAR:w
+
+{{{
+:s/FOO/BAR/g
+  }}}
+  
+
+[[index]]

tech/wireless_usb.wiki

@@ -0,0 +1,40 @@
+ = Wireless USB =
+ 
+ Provided a usb device over a network for another device
+ Best done with a [[raspberry_pi|Raspberry pi]]
+ 
+ == Steps ==
+ 
+ First you'll want a working pi with an internet connection. Be sure its
+ updated
+ 
+1) sudo apt-get install usbip
+  - This is the actual kernel module that will be doing the heavy lifting
+2) sudo modprobe usbip_host
+  - load the module into the kernel
+3) now edit your modules file to add usbip on boot
+   {{{
+   #file: /etc/modules
+   usbip_host
+     }}}
+4) Find the device you want to share (lsusb). Keep this in mind
+5) usbip list -p -l
+  - This will list all the usb devices in a way usbip can understand. Find the
+    matching busid from above for your device
+6) usbip bind --busid=<BUSID>
+  - Will bind the usb device to usbip
+7) sudo usbipd
+  - Starts the usbip daemon. Will display what it is listening on
+8) On the client machine, install usbip as well.
+9) sudo modprobe vhci-hcd 
+  - Load the module for networked usb
+  - Be sure that you have USB/IP support enabled compiled into your kernel
+10) (Optional) /etc/modules
+  - Same as the pi
+11) sudo usbip attach -r <PI_IP> -b <BUSID>
+  - Binds the usb device 
+
+And thats it! It should work now. This doesn't have to be with a raspberry pi
+it can be with any device
+
+[[index]]