pc386 BSP/master branch build failure with smp enabled.

[Karel Gardas]

Hello,

I've built 6/rtems-i386 tools using master branch of rtems-source-builder.

$ i386-rtems6-gcc -v
Using built-in specs.
COLLECT_GCC=i386-rtems6-gcc
COLLECT_LTO_WRAPPER=/export/home/karel/sfw/rtems/6-head-2020-09-11/libexec/gcc/i386-rtems6/10.2.1/lto-wrapper
Target: i386-rtems6
Configured with: ../gnu-mirror-gcc-75f5776/configure
--prefix=/export/home/karel/sfw/rtems/6-head-2020-09-11
--bindir=/export/home/karel/sfw/rtems/6-head-2020-09-11/bin
--exec_prefix=/export/home/karel/sfw/rtems/6-head-2020-09-11
--includedir=/export/home/karel/sfw/rtems/6-head-2020-09-11/include
--libdir=/export/home/karel/sfw/rtems/6-head-2020-09-11/lib
--libexecdir=/export/home/karel/sfw/rtems/6-head-2020-09-11/libexec
--mandir=/export/home/karel/sfw/rtems/6-head-2020-09-11/share/man
--infodir=/export/home/karel/sfw/rtems/6-head-2020-09-11/share/info
--datadir=/export/home/karel/sfw/rtems/6-head-2020-09-11/share
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=i386-rtems6
--disable-libstdcxx-pch --with-gnu-as --with-gnu-ld --verbose
--with-newlib --disable-nls --without-included-gettext
--disable-win32-registry --enable-version-specific-runtime-libs
--disable-lto --enable-newlib-io-c99-formats --enable-newlib-iconv
--enable-newlib-iconv-encodings=big5,cp775,cp850,cp852,cp855,cp866,euc_jp,euc_kr,euc_tw,iso_8859_1,iso_8859_10,iso_8859_11,iso_8859_13,iso_8859_14,iso_8859_15,iso_8859_2,iso_8859_3,iso_8859_4,iso_8859_5,iso_8859_6,iso_8859_7,iso_8859_8,iso_8859_9,iso_ir_111,koi8_r,koi8_ru,koi8_u,koi8_uni,ucs_2,ucs_2_internal,ucs_2be,ucs_2le,ucs_4,ucs_4_internal,ucs_4be,ucs_4le,us_ascii,utf_16,utf_16be,utf_16le,utf_8,win_1250,win_1251,win_1252,win_1253,win_1254,win_1255,win_1256,win_1257,win_1258
--enable-threads --disable-plugin --enable-libgomp --enable-languages=c,c++
Thread model: rtems
Supported LTO compression algorithms: zlib
gcc version 10.2.1 20200904 (RTEMS 6, RSB
a81a237f3e2318d88a16b31aadb82333498e06fd, Newlib a0d7982) (GCC)


I'm using those tools to build pc686 BSP with SMP enabled. The BSP is
configured with:

$ ../rtems-head/configure --prefix=$HOME/sfw/rtems/6-head-2020-09-11/
--target=i386-rtems6 --enable-maintainer-mode --enable-rtemsbsp=pc686
--enable-posix --enable-smp

The build fails with:

make[4]: Entering directory
'/export/home/karel/git/rtems/obj-rtems6/i386-rtems6/c/pc686/cpukit'
depbase=`echo score/cpu/i386/cpu_asm.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
i386-rtems6-gcc --pipe -DHAVE_CONFIG_H   -I.
-I/export/home/karel/git/rtems/obj-rtems6/i386-rtems6/c/pc686/include
-I/export/home/karel/git/rtems/rtems-head/cpukit/include
-I/export/home/karel/git/rtems/rtems-head/cpukit/score/cpu/i386/include
-I/export/home/karel/git/rtems/rtems-head/cpukit/libnetworking  -DASM
-mtune=pentiumpro -march=pentium -O2 -g -ffunction-sections
-fdata-sections -Wall -Wmissing-prototypes
-Wimplicit-function-declaration -Wstrict-prototypes -Wnested-externs
-mtune=pentiumpro -march=pentium -O2 -g -ffunction-sections
-fdata-sections -Wall -Wmissing-prototypes
-Wimplicit-function-declaration -Wstrict-prototypes -Wnested-externs -MT
score/cpu/i386/cpu_asm.o -MD -MP -MF $depbase.Tpo -c -o
score/cpu/i386/cpu_asm.o
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S &&\
mv -f $depbase.Tpo $depbase.Po
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S:
Assembler messages:
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S:54: Error:
`%edx' not allowed with `movb'
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S:78: Warning:
no instruction mnemonic suffix given and no register operands; using
default for `bts'
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S:93: Error:
`%ecx' not allowed with `movb'
../../../../../rtems-head/c/src/../../cpukit/score/cpu/i386/cpu_asm.S:118:
Error: `%edx' not allowed with `movb'
Makefile:11553: recipe for target 'score/cpu/i386/cpu_asm.o' failed
make[4]: *** [score/cpu/i386/cpu_asm.o] Error 1
make[4]: Leaving directory
'/export/home/karel/git/rtems/obj-rtems6/i386-rtems6/c/pc686/cpukit'
Makefile:1272: recipe for target 'cpukit' failed
make[3]: *** [cpukit] Error 2

it seems the problematic code was added by the patch:

commit 8937f12f1884f08c8a53fc339d60b1021846882a
Author: Jan Sommer <jan.sommer at dlr.de>
Date:   Sun May 31 16:22:54 2020 +0200

    bsp/pc386: Update context switch and restore

    Uses similar flow in cpu_asm.S for i386 as for arm.


Shall I add a ticket for this or am I doing anything wrong/unexpected here?

Thanks,
Karel