git: bd72252aace3 - main - [mips] revert r366664 - flip mips back from -O2 to -O

[Adrian Chadd]

The branch main has been updated by adrian:

URL: https://cgit.FreeBSD.org/src/commit/?id=bd72252aace382921840ddbceea712b96f4ad242

commit bd72252aace382921840ddbceea712b96f4ad242
Author:     Adrian Chadd <adrian at FreeBSD.org>
AuthorDate: 2021-01-12 21:13:20 +0000
Commit:     Adrian Chadd <adrian at FreeBSD.org>
CommitDate: 2021-01-14 07:03:53 +0000

    [mips] revert r366664 - flip mips back from -O2 to -O
    
    Now that I have -head fitting in 8MB of flash again, I can test
    out freebsd-head on my home AP test setup.  Unfortunately,
    the introduction of -O2 in r366664 causes the following infinite
    loop shortly after boot:
    
    ------
    
    MAP: No valid partition found at map/rootfs.uzip
    Warning: no time-of-day clock registered, system time will not be set accurately
    start_init: trying /sbin/init
    BAD_PAGE_FAULT: pid 1 tid 100001 (init), uid 0: pc 0x4042c320 got a read fault (type 0x2) at 0x2e3a0
    Trapframe Register Dump:
            zero: 0 at: 0   v0: 0   v1: 0
            a0: 0x1af34     a1: 0   a2: 0   a3: 0x7fffeff0
            t0: 0   t1: 0   t2: 0   t3: 0
            t4: 0   t5: 0   t6: 0   t7: 0
            t8: 0   t9: 0x152e8     s0: 0x7fffee84  s1: 0
            s2: 0   s3: 0   s4: 0   s5: 0
            s6: 0   s7: 0   k0: 0   k1: 0
            gp: 0x362c0     sp: 0x7fffedf0  s8: 0   ra: 0x40417df0
            sr: 0xf413      mullo: 0        mulhi: 0        badvaddr: 0x2e3a0
            cause: 0xffffffff80000008       pc: 0x4042c31c
    Page table info for pc address 0x4042c320: pde = 0x80712000, pte = 0xa002065a
    Dumping 4 words starting at pc address 0x4042c320:
    8f9980e0 80820000 10400067 00809825
    Page table info for bad address 0x2e3a0: pde = 0, pte = 0
    
    ------
    
    I'm not yet sure why, but until I figure it out with the mips64/cheri
    folk this should be reverted.
    
    This should only use -O on GCC generated code for MIPS platforms.
    
    Tested:
    
    * QCA934x (mips74k) - WDR-3600/WDR-4300 APs
    
    Differential Revision: https://reviews.freebsd.org/D28122
---
 share/mk/sys.mk | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/share/mk/sys.mk b/share/mk/sys.mk
index 8f456b28593a..72f458397683 100644
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@@ -166,7 +166,14 @@ CC		?=	c89
 CFLAGS		?=	-O
 .else
 CC		?=	cc
+.if ${MACHINE_CPUARCH} == "mips" && ${COMPILER_TYPE} == "gcc"
+# Note: there are currently issues generating code gcc-6.x targeting
+# code for at least mips32.  The system hits infinite page faults
+# when starting /sbin/init if -O2 is used.
+CFLAGS		?=	-O -pipe
+.else
 CFLAGS		?=	-O2 -pipe
+.endif
 .if defined(NO_STRICT_ALIASING)
 CFLAGS		+=	-fno-strict-aliasing
 .endif