Replace sptbr with satp throughout

The RISC-V Privileged ISA v1.10 uses satp instead of sptbr. Although
GCC can cope with sptbr, clang cannot. It fails with:

  error: operand must be a valid system register name or an integer in
  the range [0, 4095]

Modified the variable name in vm.c as well to ensure consistency and
avoid possible confusion.

2 files changed, 4 insertions, 4 deletions

diff --git a/p/riscv_test.h b/p/riscv_test.h
index 2b6ff83..a08f49e 100644
--- a/p/riscv_test.h
+++ b/p/riscv_test.h
@@ -110,7 +110,7 @@
 #define INIT_SATP                                                      \
   la t0, 1f;                                                            \
   csrw mtvec, t0;                                                       \
-  csrwi sptbr, 0;                                                       \
+  csrwi satp, 0;                                                       \
   .align 2;                                                             \
 1:
 
diff --git a/v/vm.c b/v/vm.c
index 71700f5..d03f3b1 100644
--- a/v/vm.c
+++ b/v/vm.c
@@ -253,10 +253,10 @@ void vm_boot(uintptr_t test_addr)
 # error
 #endif
   uintptr_t vm_choice = SATP_MODE_CHOICE;
-  uintptr_t sptbr_value = ((uintptr_t)l1pt >> PGSHIFT)
+  uintptr_t satp_value = ((uintptr_t)l1pt >> PGSHIFT)
                         | (vm_choice * (SATP_MODE & ~(SATP_MODE<<1)));
-  write_csr(sptbr, sptbr_value);
-  if (read_csr(sptbr) != sptbr_value)
+  write_csr(satp, satp_value);
+  if (read_csr(satp) != satp_value)
     assert(!"unsupported satp mode");
 
   // Set up PMPs if present, ignoring illegal instruction trap if not.