diff --git a/linker.ld b/linker.ld
index d57403d..d583890 100644
--- a/linker.ld
+++ b/linker.ld
@@ -5,7 +5,7 @@ SECTIONS
     .text.start : { *(.text.start) }
     .text : { *(.text) }
     .data : { *(.data) }
-    .bss : { *(.bss COMMON) }
+    .bss : { __bss_start = .; *(.bss COMMON) } __bss_end = .;
     .rodata : { *(.rodata) }
     . = ALIGN(4);
 }
diff --git a/source/start.s b/source/start.s
index c108bc6..ecc3ebf 100644
--- a/source/start.s
+++ b/source/start.s
@@ -77,6 +77,15 @@ start:
     mcr p15, 0, r8, c2, c0, 0   @ Data cacheable 0, 2, 4
     mcr p15, 0, r8, c2, c0, 1   @ Inst cacheable 0, 2, 4
 
+    @ Clear BSS
+    ldr r0, =__bss_start
+    ldr r1, =__bss_end
+    mov r2, #0
+    clear_bss_loop:
+        str r2, [r0], #4
+        cmp r0, r1
+        blo clear_bss_loop
+
     @ Enable caches / MPU / ITCM
     mrc p15, 0, r0, c1, c0, 0  @ read control register
     orr r0, r0, #(1<<18)       @ - ITCM enable