diff options
| author | Andrew Waterman <waterman@cs.berkeley.edu> | 2015-11-28 16:59:00 -0800 |
|---|---|---|
| committer | Andrew Waterman <waterman@cs.berkeley.edu> | 2015-11-28 17:00:06 -0800 |
| commit | 529a6a3a0c42468bf815255697279e0e059a22db (patch) | |
| tree | d1c6786e02820ea4714154cb8cb265d529771f15 /pk/mentry.S | |
| parent | d37b50edf5faee2fe41a2586479ddab7c8a2ec9b (diff) | |
| download | pk-529a6a3a0c42468bf815255697279e0e059a22db.zip pk-529a6a3a0c42468bf815255697279e0e059a22db.tar.gz pk-529a6a3a0c42468bf815255697279e0e059a22db.tar.bz2 | |
Change boot procedure to not rely on IPIs
That procedure doesn't work correctly if hart 0 comes out of reset while
hart 1 is still in reset.
Diffstat (limited to 'pk/mentry.S')
| -rw-r--r-- | pk/mentry.S | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/pk/mentry.S b/pk/mentry.S index 26ed83c..7f0fc61 100644 --- a/pk/mentry.S +++ b/pk/mentry.S @@ -166,28 +166,35 @@ mentry: li x30, 0 li x31, 0 + csrr a0, mhartid + bnez a0, .LmultiHart + # sp <- end of first full page after the end of the binary la sp, _end + 2*RISCV_PGSIZE - 1 li t0, -RISCV_PGSIZE and sp, sp, t0 addi sp, sp, -MENTRY_FRAME_SIZE - csrr a0, mhartid - bnez a0, .LmultiHart - csrw mscratch, sp j init_first_hart .LmultiHart: + # make sure our hart id is within a valid range + li a1, MAX_HARTS + bgeu a0, a1, .LmultiHart - # wait for IPI to signal that it's time to boot - wfi - csrr a0, mip - andi a0, a0, MIP_MSIP - beqz a0, .LmultiHart - + # signal we're ready to boot + csrw mscratch, x0 fence - csrr sp, mscratch + li a1, 1 + sll a1, a1, a0 + la a2, booted_harts_mask + amoor.w x0, a1, (a2) + + # wait for main hart to grant us a stack +1:csrr sp, mscratch + beqz sp, 1b + j init_other_hart .Linterrupt: |