Function examples_exit_zero_in_vm

tests/integration/vm_execution.rs:1065–1083

()

    ]);
    assert!(
        matches!(outcome, StepOutcome::Halted(25)),
        "expected Halted(25), got {outcome:?}"
    );
}

#[test]
fn test_ecall_write_uart() {
    // Write "hi\n" to stdout via ecall 64, then exit. Registers are named by
    // number here: t0=x5, t1=x6, sp=x2, a0=x10, a1=x11, a2=x12, a7=x17.
    let assembled = Assembler::assemble(&[
        ri(RealInstruction::Addi(Addi::new(5, 2, -4))), // t0 = sp - 4 (buffer ptr)
        ri(RealInstruction::Addi(Addi::new(6, 0, 0x68))), // t1 = 'h' (104)
        ri(RealInstruction::Sb(Sb::new(5, 6, 0))),      // sb t1, 0(t0)
        ri(RealInstruction::Addi(Addi::new(6, 0, 0x69))), // t1 = 'i' (105)
        ri(RealInstruction::Sb(Sb::new(5, 6, 1))),      // sb t1, 1(t0)
        ri(RealInstruction::Addi(Addi::new(6, 0, 0x0A))), // t1 = '\n' (10)
        ri(RealInstruction::Sb(Sb::new(5, 6, 2))),      // sb t1, 2(t0)
        // ecall write: a0=1 (fd=stdout), a1=buf, a2=3 (len), a7=64
        ri(RealInstruction::Addi(Addi::new(10, 0, 1))), // a0 = 1 (fd)
        ri(RealInstruction::Add(Add::new(11, 5, 0))),   // a1 = t0 (buf ptr)
        ri(RealInstruction::Addi(Addi::new(12, 0, 3))), // a2 = 3 (len)
        ri(RealInstruction::Addi(Addi::new(17, 0, 64))), // a7 = 64 (write)