arch-riscv: Correct syscall argument reg count

As per the discussion in patch #6904 and the Linux 4.15 kernel code for
RISC-V, RISC-V has 7 system call argument registers, x10 through x16 (a0
through a6), with x17 (a7) being used for the system call number.

Change-Id: I0080eca78ffa844b322bb2cff2a51ab2815f3809
Reviewed-on: https://gem5-review.googlesource.com/7081
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tuan Ta <qtt2@cornell.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

diff --git a/src/arch/riscv/registers.hh b/src/arch/riscv/registers.hh
index 01e38595728d0a3005e2ad04700f9709faad69f9..a61554c132e206b79df03a47d01e316fecaa68ef 100644 (file)
--- a/src/arch/riscv/registers.hh
+++ b/src/arch/riscv/registers.hh
@@ -97,6 +97,10 @@ const std::vector<int> ReturnValueRegs = {10, 11};
 const std::vector<int> ArgumentRegs = {10, 11, 12, 13, 14, 15, 16, 17};
 const int AMOTempReg = 32;
 
+const int SyscallPseudoReturnReg = 10;
+const std::vector<int> SyscallArgumentRegs = {10, 11, 12, 13, 14, 15, 16};
+const int SyscallNumReg = 17;
+
 const std::vector<std::string> IntRegNames = {
     "zero", "ra", "sp", "gp",
     "tp", "t0", "t1", "t2",
@@ -118,10 +122,6 @@ const std::vector<std::string> FloatRegNames = {
     "ft8", "ft9", "ft10", "ft11"
 };
 
-const int SyscallNumReg = 17;
-const std::vector<int> SyscallArgumentRegs = {10, 11, 12, 13};
-const int SyscallPseudoReturnReg = 10;
-
 enum MiscRegIndex {
     MISCREG_USTATUS = 0x000,
     MISCREG_UIE = 0x004,