arch: Make endianness a property of the OS class syscalls can consume.

That way the syscall implementations won't have to find the right
endianness to use on their own, typically by referring to TheISA.

Change-Id: I186b2f419d5dbee72cc9b5abce7356f3143f0c83
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22363
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/alpha/linux/linux.hh

@@ -42,6 +42,8 @@ class AlphaLinux : public Linux
 {
   public:
 
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+
     static const int TGT_SIGHUP         = 0x000001;
     static const int TGT_SIGINT         = 0x000002;
     static const int TGT_SIGQUIT        = 0x000003;

src/arch/arm/freebsd/freebsd.hh

@@ -35,10 +35,15 @@
 
 #include "kern/freebsd/freebsd.hh"
 
-class ArmFreebsd32 : public FreeBSD
+class ArmFreebsd : public FreeBSD
 {
   public:
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+};
 
+class ArmFreebsd32 : public ArmFreebsd
+{
+  public:
     /// This table maps the target open() flags to the corresponding
     /// host open() flags.
     static SyscallFlagTransTable openFlagTable[];
@@ -192,7 +197,7 @@ class ArmFreebsd32 : public FreeBSD
     };
 };
 
-class ArmFreebsd64 : public FreeBSD
+class ArmFreebsd64 : public ArmFreebsd
 {
   public:
 

src/arch/arm/linux/linux.hh

@@ -51,6 +51,8 @@
 class ArmLinux : public Linux
 {
   public:
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+
     static void
     archClone(uint64_t flags,
               Process *pp, Process *cp,

src/arch/mips/linux/linux.hh

@@ -37,6 +37,8 @@ class MipsLinux : public Linux
 {
   public:
 
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+
     static const int TGT_SIGHUP         = 0x000001;
     static const int TGT_SIGINT         = 0x000002;
     static const int TGT_SIGQUIT        = 0x000003;

src/arch/power/linux/linux.hh

@@ -42,6 +42,8 @@ class PowerLinux : public Linux
 {
   public:
 
+    static const ByteOrder byteOrder = BigEndianByteOrder;
+
     typedef int32_t time_t;
 
     typedef struct {

src/arch/riscv/linux/linux.hh

@@ -34,7 +34,13 @@
 #include "arch/riscv/utility.hh"
 #include "kern/linux/linux.hh"
 
-class RiscvLinux64 : public Linux
+class RiscvLinux : public Linux
+{
+  public:
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+};
+
+class RiscvLinux64 : public RiscvLinux
 {
   public:
     static const int TGT_SIGHUP         =  1;
@@ -203,7 +209,7 @@ class RiscvLinux64 : public Linux
     }
 };
 
-class RiscvLinux32 : public Linux
+class RiscvLinux32 : public RiscvLinux
 {
   public:
     static const int TGT_SIGHUP         =  1;

src/arch/sparc/linux/linux.hh

@@ -38,6 +38,8 @@ class SparcLinux : public Linux
 {
   public:
 
+    static const ByteOrder byteOrder = BigEndianByteOrder;
+
     typedef struct {
         uint32_t st_dev;
         char __pad1[4];

src/arch/sparc/solaris/solaris.hh

@@ -37,6 +37,8 @@ class SparcSolaris : public Solaris
 {
   public:
 
+    static const ByteOrder byteOrder = BigEndianByteOrder;
+
     static SyscallFlagTransTable openFlagTable[];
 
     static const int TGT_O_RDONLY       = 0x00000000;   //!< O_RDONLY

src/arch/x86/linux/linux.hh

@@ -46,6 +46,8 @@
 class X86Linux : public Linux
 {
   public:
+    static const ByteOrder byteOrder = LittleEndianByteOrder;
+
     static void
     archClone(uint64_t flags,
                           Process *pp, Process *cp,