ArmPkg: ARM v8.2 updates for detecting FP

[mirror_edk2.git] / ArmPkg / Library / ArmLib / AArch64 / AArch64Support.S

diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S b/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
index dde6a756528f3abf1bd5a142448e42122a9bd8fa..2d136d242b943fe2f365bc824953b7fe10c944b7 100644 (file)
--- a/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
+++ b/ArmPkg/Library/ArmLib/AArch64/AArch64Support.S
@@ -1,7 +1,7 @@
 #------------------------------------------------------------------------------\r
 #\r
 # Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>\r
-# Copyright (c) 2011 - 2014, ARM Limited. All rights reserved.\r
+# Copyright (c) 2011 - 2017, ARM Limited. All rights reserved.\r
 # Copyright (c) 2016, Linaro Limited. All rights reserved.\r
 #\r
 # This program and the accompanying materials\r
@@ -403,9 +403,11 @@ ASM_FUNC(ArmEnableVFP)
   mov   x1, x30                 // Save LR\r
   bl    ArmReadIdPfr0           // Read EL1 Processor Feature Register (PFR0)\r
   mov   x30, x1                 // Restore LR\r
-  ands  x0, x0, #AARCH64_PFR0_FP// Extract bits indicating VFP implementation\r
-  cmp   x0, #0                  // VFP is implemented if '0'.\r
-  b.ne  4f                      // Exit if VFP not implemented.\r
+  ubfx  x0, x0, #16, #4         // Extract the FP bits 16:19\r
+  cmp   x0, #0xF                // Check if FP bits are '1111b',\r
+                                // i.e. Floating Point not implemented\r
+  b.eq  4f                      // Exit when VFP is not implemented.\r
+\r
   // FVP is implemented.\r
   // Make sure VFP exceptions are not trapped (to any exception level).\r
   mrs   x0, cpacr_el1           // Read EL1 Coprocessor Access Control Register (CPACR)\r