Arch agnostic infrastructure getting started at: Section 28, “Userland assembly”.
x86 registers
x86 addressing modes
x86 data transfer instructions
x86 binary arithmetic instructions
x86 logical instructions
x86 shift and rotate instructions
x86 bit and byte instructions
x86 control transfer instructions
x86 miscellaneous instructions
x86 random number generator instructions
x86 x87 FPU instructions
x86 SIMD
x86 system instructions
x86 thread synchronization primitives
x86 assembly bibliography