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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-06-22 13:58:11 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2018-06-28 15:02:13 +0200 |
| commit | 5f5c450aa49ba73dccb52cd8f6e62c6aef1412da (patch) | |
| tree | 49ebe86ae1a262c1f3ad8f2c0e05b859c0af279b | |
| parent | bsp/riscv: Add device tree support (diff) | |
| download | rtems-5f5c450aa49ba73dccb52cd8f6e62c6aef1412da.tar.bz2 | |
bsp/riscv: Add SMP startup synchronization
Update #3433.
| -rw-r--r-- | bsps/riscv/riscv/start/start.S | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/bsps/riscv/riscv/start/start.S b/bsps/riscv/riscv/start/start.S index f40ceeff50..b59e55f2ea 100644 --- a/bsps/riscv/riscv/start/start.S +++ b/bsps/riscv/riscv/start/start.S @@ -42,7 +42,7 @@ PUBLIC(bsp_start_vector_table_begin) PUBLIC(bsp_start_vector_table_end) PUBLIC(_start) - .section .bsp_start_text, "ax", @progbits + .section .bsp_start_text, "wax", @progbits .align 2 TYPE_FUNC(_start) @@ -55,7 +55,7 @@ SYM(_start): #ifdef RTEMS_SMP csrr s0, mhartid - bnez s0, .Lloop_forever + bnez s0, .Lwait_for_go #endif /* load stack and frame pointers */ @@ -75,6 +75,13 @@ SYM(_start): la a2, bsp_section_bss_size call memset +#ifdef RTEMS_SMP + /* Give go to secondary processors */ + la t0, .Lsecondary_processor_go + fence iorw,ow + amoswap.w zero, zero, 0(t0) +#endif + /* Init FPU unit if it's there */ li t0, MSTATUS_FS csrs mstatus, t0 @@ -82,8 +89,19 @@ SYM(_start): j boot_card #ifdef RTEMS_SMP + /* Wait for go issued by the boot processor (mhartid == 0) */ +.Lwait_for_go: + la t0, .Lsecondary_processor_go +.Lwait_for_go_again: + lw t1, 0(t0) + fence iorw, iorw + sext.w t1, t1 + bnez t1, .Lwait_for_go_again .Lloop_forever: j .Lloop_forever + +.Lsecondary_processor_go: + .word 0xdeadbeef #endif .align 4 |