diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uread.asm b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uread.asm
index da3ea3e31e..9aefa808de 100644
--- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uread.asm
+++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uread.asm
@@ -15,6 +15,7 @@
 
 
     EXPORT  __aeabi_uread4
+    EXPORT  __aeabi_uread8
 
     AREA  Uread4, CODE, READONLY
 
@@ -35,4 +36,31 @@ __aeabi_uread4
     orr     r0, r1, r0, lsl #24
     bx      lr
 
+;
+;UINT64
+;EFIAPI
+;__aeabi_uread8 (
+;  IN VOID   *Pointer
+;  );
+;
+__aeabi_uread8
+    mov	    r3, r0
+
+    ldrb    r1, [r3]
+    ldrb    r2, [r3, #1]
+    orr     r1, r1, r2, lsl #8
+    ldrb    r2, [r3, #2]
+    orr     r1, r1, r2, lsl #16
+    ldrb    r0, [r3, #3]
+    orr     r0, r1, r0, lsl #24
+
+    ldrb    r1, [r3, #4]
+    ldrb    r2, [r3, #5]
+    orr     r1, r1, r2, lsl #8
+    ldrb    r2, [r3, #6]
+    orr     r1, r1, r2, lsl #16
+    ldrb    r2, [r3, #7]
+    orr     r1, r1, r2, lsl #24
+
+    bx      lr
     END
diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uwrite.asm b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uwrite.asm
index deb0189327..cbf1793af4 100644
--- a/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uwrite.asm
+++ b/ArmPkg/Library/CompilerIntrinsicsLib/Arm/uwrite.asm
@@ -14,6 +14,7 @@
 
 
     EXPORT  __aeabi_uwrite4
+    EXPORT  __aeabi_uwrite8
 
     AREA  Uwrite4, CODE, READONLY
 
@@ -35,6 +36,31 @@ __aeabi_uwrite4
     mov     r2, r0, lsr #24
     strb    r2, [r1, #3]
     bx      lr
- 
+
+;
+;UINT64
+;EFIAPI
+;__aeabi_uwrite8 (
+;  IN UINT64 Data,    //r0-r1
+;  IN VOID   *Pointer //r2
+;  );
+;
+;
+__aeabi_uwrite8
+    mov     r3, r0, lsr #8
+    strb    r0, [r2]
+    strb    r3, [r2, #1]
+    mov     r3, r0, lsr #16
+    strb    r3, [r2, #2]
+    mov     r3, r0, lsr #24
+    strb    r3, [r2, #3]
+
+    mov     r3, r1, lsr #8
+    strb    r1, [r2, #4]
+    strb    r3, [r2, #5]
+    mov     r3, r1, lsr #16
+    strb    r3, [r2, #6]
+    mov     r3, r1, lsr #24
+    strb    r3, [r2, #7]
     END