ARM BASICS

STR Rx, [Ry]

• STORE the value of Rx into the memory with address saved in Ry. So, it's not 'Save value of R3 into R1.' More precisely, suppose R1 has memory address 0x1234, then program will look up memory 0x1234 and save the value there, not directly into R1.

LDR Rx, [Ry]

• Program: I will look up the value of Ry, that will be your memory address I will look up, then I will load the value in that memory into Rx.

To wake up cores, you need to

1. Save the program counter somewhere
2. Save the #0xe0 or #0xe8 or #0xf0 for core 1, 2, and 3 respectively
3. Move the PC address into the memory address above.