Resolve conversation of #79

examples/x86_64/linker.ld

@@ -1,4 +1,4 @@
-OUTPUT_ARCH(riscv)
+OUTPUT_ARCH(i386:x86-64)
 ENTRY(_start)
 
 BASE_ADDRESS = 0x200000;
@@ -43,5 +43,5 @@ SECTIONS
     }
 
     . = ALIGN(4K);
-    PROVIDE(end = .);
+    PROVIDE(dma_region = .);
 }

examples/x86_64/src/hal.rs

@@ -7,11 +7,12 @@ use log::trace;
 use virtio_drivers::{BufferDirection, Hal, PhysAddr, PAGE_SIZE};
 
 extern "C" {
-    fn end();
+    static dma_region: u8;
 }
 
 lazy_static! {
-    static ref DMA_PADDR: AtomicUsize = AtomicUsize::new(end as usize);
+    static ref DMA_PADDR: AtomicUsize =
+        AtomicUsize::new(unsafe { &dma_region as *const u8 as usize });
 }
 
 pub struct HalImpl;

examples/x86_64/src/logger.rs

@@ -15,8 +15,7 @@ struct Logger {
 
 /// Initialises UART logger.
 pub fn init(max_level: LevelFilter) -> Result<(), SetLoggerError> {
-    // Safe because BASE_ADDRESS is the base of the MMIO region for a UART and is mapped as device
-    // memory.
+    // Safe because `0x3f8` is COM1 I/O port.
     let mut uart = unsafe { SerialPort::new(0x3f8) };
     uart.init();
     LOGGER.uart.lock().replace(uart);