Assembly: Access and Store information in Memory

Sizes of C data types in X86-64

Operand forms in X86-64

M[Addr] means a reference to the value stored in memory starting at address Addr.

The memory of address Addr could come from user space, CPU and MLU works together to get the physical page (PA) from Page Table, then access the PA in RAM.

RISC-V Integer Instructions

The operand forms is basically the same. lb D, S sb S, D

Example: sd ra,40(sp) Save 8 bytes (double) from ra register to memory address of (sp + 40).