base, sim: Make ByteOrder into a ScopedEnum accessible to Python

There is currently no good way of passing a byte order as a Param
since the ByteOrder type is defined in C++. Make this into a generated
ScopedEnum that can be used in Params.

Change-Id: I990f402340c17c4e0799de57df19516ae61794d4
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33174
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>

src/base/pixel.cc

@@ -43,10 +43,10 @@
 
 const PixelConverter PixelConverter::rgba8888_le(4, 0, 8, 16, 8, 8, 8);
 const PixelConverter PixelConverter::rgba8888_be(4, 0, 8, 16, 8, 8, 8,
-                                                 BigEndianByteOrder);
+                                                 ByteOrder::big);
 const PixelConverter PixelConverter::rgb565_le(2,  0, 5, 11, 5, 6, 5);
 const PixelConverter PixelConverter::rgb565_be(2,  0, 5, 11, 5, 6, 5,
-                                               BigEndianByteOrder);
+                                               ByteOrder::big);
 
 PixelConverter::PixelConverter(unsigned _length,
                                unsigned ro, unsigned go, unsigned bo,
@@ -74,7 +74,7 @@ PixelConverter::readWord(const uint8_t *p) const
 {
     uint32_t word(0);
 
-    if (byte_order == LittleEndianByteOrder) {
+    if (byte_order == ByteOrder::little) {
         for (int i = 0; i < length; ++i)
             word |= p[i] << (8 * i);
     } else {
@@ -88,7 +88,7 @@ PixelConverter::readWord(const uint8_t *p) const
 void
 PixelConverter::writeWord(uint8_t *p, uint32_t word) const
 {
-    if (byte_order == LittleEndianByteOrder) {
+    if (byte_order == ByteOrder::little) {
         for (int i = 0; i < length; ++i)
             p[i] = (word >> (8 * i)) & 0xFF;
     } else {

src/base/pixel.hh

@@ -127,7 +127,7 @@ class PixelConverter
     PixelConverter(unsigned length,
                    unsigned ro, unsigned go, unsigned bo,
                    unsigned rw, unsigned gw, unsigned bw,
-                   ByteOrder byte_order = LittleEndianByteOrder);
+                   ByteOrder byte_order = ByteOrder::little);
 
     /** Get the Pixel representation of a color word. */
     Pixel toPixel(uint32_t word) const {

src/base/types.hh

@@ -43,6 +43,8 @@
 #include <stdexcept>
 
 #include "base/refcnt.hh"
+/* Hide the fact that this enum is generated by Python */
+#include "enums/ByteOrder.hh"
 
 /** uint64_t constant */
 #define ULL(N)          ((uint64_t)N##ULL)
@@ -242,9 +244,4 @@ typedef std::shared_ptr<FaultBase> Fault;
 // we just create an alias.
 constexpr decltype(nullptr) NoFault = nullptr;
 
-enum ByteOrder {
-    BigEndianByteOrder,
-    LittleEndianByteOrder
-};
-
 #endif // __BASE_TYPES_HH__

src/base/vnc/vncserver.cc

@@ -75,7 +75,7 @@ const PixelConverter VncServer::pixelConverter(
     4,        // 4 bytes / pixel
     16, 8, 0, // R in [23, 16], G in [15, 8], B in [7, 0]
     8, 8, 8,  // 8 bits / channel
-    LittleEndianByteOrder);
+    ByteOrder::little);
 
 /** @file
  * Implementiation of a VNC server
@@ -130,7 +130,7 @@ VncServer::VncServer(const Params *p)
     // around for telling the client and making sure it cooperates
     pixelFormat.bpp = 8 * pixelConverter.length;
     pixelFormat.depth = pixelConverter.depth;
-    pixelFormat.bigendian = pixelConverter.byte_order == BigEndianByteOrder;
+    pixelFormat.bigendian = pixelConverter.byte_order == ByteOrder::big;
     pixelFormat.truecolor = 1;
     pixelFormat.redmax = pixelConverter.ch_r.mask;
     pixelFormat.greenmax = pixelConverter.ch_g.mask;