Data location in solidity assembly

Memory Example


					function getData(uint value) public view returns (bytes32 output) {
						assembly {
						  function allocate(length) -> pos {
							let freePointer := 0x40
							pos := mload(freePointer)
							mstore(freePointer, add(pos,length))
						  }	
						 let dataSize := 0x20  // 32 bytes
						 let offset := allocate(dataSize)
						 mstore(offset, value)
						 return(offset, dataSize)
						}
					 }

Calldata demo


					 // return calldata as bytes output
					function getData(uint input) public view returns (bytes memory output) {
					 assembly {
						 let base := mload(0x40)
						 mstore(add(base, 0x00), 0x20) // pointer to data
						 mstore(add(base, 0x20), 36) // data length
						 calldatacopy(add(base, 0x40), 0, 36)  // data from byte 0
						 return(base, 0x80)
						}
					  }

Storage demo


					uint8 data1 = 1;
					uint8 data2 = 2;
					uint8 data3 = 3;
					uint8 data4 = 4;
						
					// get data3 and return it as ouput
					function getData() public view returns(bytes32){
						assembly {
							let data := sload(data3_slot)
							let result := and(shr(shl(3,data3.offset), data), 0xff)
							mstore(0, result)
							return(0,32)
						}
					}