diff options
Diffstat (limited to 'debug/programs/entry.S')
| -rwxr-xr-x | debug/programs/entry.S | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/debug/programs/entry.S b/debug/programs/entry.S index e021860..c9e319c 100755 --- a/debug/programs/entry.S +++ b/debug/programs/entry.S @@ -30,8 +30,23 @@ handle_reset: la t0, trap_entry csrw mtvec, t0 csrwi mstatus, 0 + + // make sure these registers exist by seeing if either S or U bits + // are set before attempting to zero them out. + csrr t1, misa + addi t2, x0, 1 + slli t2, t2, 20 // U_EXTENSION + and t2, t1, t2 + bne x0, t2, 1f + addi t2, x0, 1 + slli t2, t2, 18 // S_EXTENSION + and t2, t1, t2 + bne x0, t2, 1f + j 2f +1: csrwi mideleg, 0 csrwi medeleg, 0 +2: csrwi mie, 0 # initialize global pointer |