8 * Von Neumman and the stored program
13 * Data, addresses and control registers
20 * Paging and Virtual Memory
21 * Operation Reordering
26 * Different stack and context
27 * Must enable, disable, ack
31 * Protected instructions
35 # Multi-processor systems
44 * Different address space
45 * Memory mapped registers
54 * Software layer providing abstraction
56 - Filesystem instead of disk drive
57 - Virtual memory and transparent swap instead of overlays
69 * Inter-process communication
75 * Memory hierarchy ("secondary" memory or storage)
88 # Mechanism and policy
90 * Provide mechanism in kernel space
91 * Allow policy to user space
93 # Unix, GNU, Linux and POSIX
98 * Ken Thompson and Unix
99 * Dennis Ritchie and C language
102 * RMS and GNU Project
113 * utils: GNU coreutils
114 * System: GNU + Linux
115 * Other systems: *BSD, OpenSolaris, etc
117 # Systems using Linux
119 * toolchain is always GNU
120 - Intel CC and tcc build Linux, but their use is unknown
121 * libc: uclibc, dietlibc, eglibc, others...
126 * Most systems are GNU + Linux
128 * Debian GNU/kFreeBSD
144 # Intellectual Rights
155 * Free Software Foundation
160 * Public Domain allows changes to be non-free
161 * The author may give permissions through licenses
162 * The license may request conditions on distribution
163 * A copyleft license requires the work to be kept free
169 * Allows source code redistribution, including a fee
170 * Allows modifications and their distribution on the condition that they are
171 marked as so and licensed as GPL too
172 * Allows distribution of binaries, when source code access is still possible
173 * Does not allow further restrictions
177 * The GPL requires the software to be free as in "free beer" - FALSE
178 * The GPL requires modifications to be published - FALSE
179 * The GPL requires all my code to be GPL - FALSE
181 # License compatibility
183 * All requirements must be satisfied simultaneously
184 * The GPL does not allow further requirements
185 * You can only combine GPL code with code licensed with no restrictions besides