Function asm_block_round_trip

tests/vm_diag_test.rs:264–294

()

fn asm_block_round_trip() {
    let src = r#"
; Writes a single byte via the Linux write syscall (syscall 64).
; This mirrors a low-level write wrapper, implemented in HLL inline asm.
write_byte: (c: i32) -> i32 {
    asm {
        addi  sp, sp, -16
        sd    ra, 8(sp)
        sb    a0, 7(sp)
        li    a0, 1
        addi  a1, sp, 7
        li    a2, 1
        li    a7, 64
        ecall
        ld    ra, 8(sp)
        addi  sp, sp, 16
    }
    return 0
}

main: () -> i32 {
    write_byte(72)   ; 'H'
    write_byte(105)  ; 'i'
    write_byte(10)   ; '\n'
    return 0
}
"#;
    let (uart, exit) = link_stdlib_and_run(src);
    assert_eq!(uart.trim_end_matches('\n'), "Hi");
    assert_eq!(exit, Some(0));
}