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| author | Paul Burton <paul.burton@imgtec.com> | 2016-09-21 13:59:54 (GMT) |
|---|---|---|
| committer | Daniel Schwierzeck <daniel.schwierzeck@gmail.com> | 2016-09-21 15:04:53 (GMT) |
| commit | 31d36f748c52b22833aa946f6c406cc8fb2f1908 (patch) | |
| tree | 3eec119018d0fc405e56e333c244af6e60bd5a04 /arch/mips/cpu | |
| parent | d263cda5ae41279208d9576eab1c5215a57252a6 (diff) | |
| download | u-boot-fsl-qoriq-31d36f748c52b22833aa946f6c406cc8fb2f1908.tar.xz | |
MIPS: Hang if run on a secondary CPU
Some systems are configured such that multiple CPUs begin running from
their reset vector following a system reset. If this occurs then U-Boot
will be run on multiple CPUs simultaneously, which causes all sorts of
issues as the multiple instances of U-Boot clobber each other.
Prevent this from happening by simply hanging with an infinite loop if
we run on a CPU whose ID, as determined by GlobalNumber or EBase.CPUNum
as appropriate, is non-zero.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Diffstat (limited to 'arch/mips/cpu')
| -rw-r--r-- | arch/mips/cpu/start.S | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/mips/cpu/start.S b/arch/mips/cpu/start.S index cbc02fa..3f0fc12 100644 --- a/arch/mips/cpu/start.S +++ b/arch/mips/cpu/start.S @@ -108,9 +108,28 @@ ENTRY(_start) .align 4 reset: +#if __mips_isa_rev >= 6 + mfc0 t0, CP0_CONFIG, 5 + and t0, t0, MIPS_CONF5_VP + beqz t0, 1f + nop + + b 2f + mfc0 t0, CP0_GLOBALNUMBER +#endif + +1: mfc0 t0, CP0_EBASE + and t0, t0, EBASE_CPUNUM + + /* Hang if this isn't the first CPU in the system */ +2: beqz t0, 4f + nop +3: wait + b 3b + nop /* Clear watch registers */ - MTC0 zero, CP0_WATCHLO +4: MTC0 zero, CP0_WATCHLO mtc0 zero, CP0_WATCHHI /* WP(Watch Pending), SW0/1 should be cleared */ |