What is LDR in ARM assembly?
Table of Contents
What is LDR in ARM assembly?
The LDR pseudo-instruction is used for two main purposes: to generate literal constants when an immediate value cannot be moved into a register because it is out of range of the MOV and MVN instructions. to load a program-relative or external address into a register.
What is LDR instruction?
The LDR Rd,= label pseudo-instruction places an address in a literal pool and then loads the address into a register. LDR Rd,= label can load any 32-bit numeric value into a register. It also accepts PC-relative expressions such as labels, and labels with offsets.
What does STR do in arm?
STR instructions store a register value into memory. The memory address to load from or store to is at an offset from the register Rn . The offset is specified by the register Rm and can be shifted left by up to 3 bits using LSL . The value to load or store can be a byte, halfword, or word.
What is str Assembly?
STR instructions store a register value into memory. The memory address to load from or store to is at an offset from the register Rn . The value to load or store can be a byte, halfword, or word.
What is LDRB in assembly language?
Load Register Byte (register) calculates an address from a base register value and an offset register value, loads a byte from memory, zero-extends it to form a 32-bit word, and writes it to a register.
What is SWI in ARM?
The Software Interrupt instruction (SWI) is used to enter Supervisor mode, usually to request a particular supervisor function. The SWI handler reads the opcode to extract the SWI function number. A SWI handler returns by executing the following irrespective of the processor operating state: MOVS PC, R14_svc.
What does the B mean in LDRB or what is the difference between LDR and LDRB in arm?
From the ARM ARM. LDRSB (Load Register Signed Byte) loads a byte from memory, sign-extends it to form a 32-bit word, and writes the result to a general-purpose register. LDRB (Load Register Byte) loads a byte from memory, zero-extends it to form a 32-bit word, and writes the result to a general-purpose register.