Build application at 0x0 in release mode.

user/src/lib.rs

@@ -11,7 +11,6 @@ mod lang_items;
 #[no_mangle]
 #[link_section = ".text.entry"]
 pub extern "C" fn _start() -> ! {
-    clear_bss();
     syscall::sys_exit(main());
     panic!("unreachable after sys_exit!");
 }
@@ -22,14 +21,5 @@ fn main() -> i32 {
     panic!("Cannot find main!");
 }
 
-fn clear_bss() {
-    extern "C" {
-        fn start_bss();
-        fn end_bss();
-    }
-    (start_bss as usize..end_bss as usize).for_each(|addr| {
-        unsafe { (addr as *mut u8).write_volatile(0); }
-    });
-}
 
 pub use syscall::*;

user/src/linker.ld

@@ -2,7 +2,7 @@
 OUTPUT_ARCH(riscv)
 ENTRY(_start)
 
-BASE_ADDRESS = 0x80100000;
+BASE_ADDRESS = 0x0;
 
 SECTIONS
 {
@@ -18,9 +18,7 @@ SECTIONS
         *(.data .data.*)
     }
     .bss : {
-        start_bss = .;
         *(.bss .bss.*)
-        end_bss = .;
     }
     /DISCARD/ : {
         *(.eh_frame)