WIP on debug testing.

[riscv-tests.git] / debug / programs / mprv.S

diff --git a/debug/programs/mprv.S b/debug/programs/mprv.S
new file mode 100644 (file)
index 0000000..df346b3
--- /dev/null
+++ b/debug/programs/mprv.S
@@ -0,0 +1,38 @@
+#include "../riscv/encoding.h"
+#define PGSHIFT         12
+
+        .global         _start
+
+        .section        .text
+_start:
+        # Set up a page table entry that maps 0x0... to 0x8...
+        la      t0, page_table
+        srli    t0, t0, PGSHIFT
+        csrw    CSR_SPTBR, t0
+
+        # update mstatus
+        csrr    t1, CSR_MSTATUS
+        li      t0, (MSTATUS_MPRV | (VM_SV39 << 24))
+        #li      t0, ((VM_SV39 << 24))
+        or      t1, t0, t1
+        csrw    CSR_MSTATUS, t1
+
+        la      t0, (loop - 0x80000000)
+        csrw    CSR_MEPC, t0
+
+        # Exit supervisor mode, entering user mode at loop.
+        mret
+
+loop:
+        la      t0, data
+        lw      t1, 0(t0)
+        j       loop
+
+        .section        .data
+data:
+        .word   0xbead
+
+        .balign 0x1000
+page_table:
+        .word   ((0x80000000 >> 2) | PTE_V | PTE_TYPE_URWX_SRWX)
+        .word   0