Message-ID:
 <PAXPR04MB84595BA5BEAE2D21F015036688232@PAXPR04MB8459.eurprd04.prod.outlook.com>
Date: Fri, 22 Nov 2024 00:13:40 +0000
From: Peng Fan <peng.fan@....com>
To: Florian Fainelli <florian.fainelli@...adcom.com>, "Peng Fan (OSS)"
	<peng.fan@....nxp.com>, Thomas Renninger <trenn@...e.com>, Shuah Khan
	<shuah@...nel.org>, "John B. Wyatt IV" <jwyatt@...hat.com>, John Kacur
	<jkacur@...hat.com>
CC: "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v2 2/2] pm: cpupower: Makefile: Allow overriding
 cross-compiling env params

> Subject: Re: [PATCH v2 2/2] pm: cpupower: Makefile: Allow overriding
> cross-compiling env params
> 
> On 11/21/24 04:40, Peng Fan wrote:
> >> Subject: Re: [PATCH v2 2/2] pm: cpupower: Makefile: Allow
> overriding
> >> cross-compiling env params
> >>
> >> Hi Peng,
> >>
> >> On 9/19/2024 5:08 AM, Peng Fan (OSS) wrote:
> >>> From: Peng Fan <peng.fan@....com>
> >>>
> >>> Allow overriding the cross-comple env parameters to make it
> easier
> >> for
> >>> Yocto users. Then cross-compiler toolchains to build cpupower
> with
> >>> only two steps:
> >>> - source (toolchain path)/environment-setup-armv8a-poky-linux
> >>> - make
> >>
> >> This patch breaks the way that buildroot builds cpupower:
> >>
> >>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2F
> >> git.buildroot.net%2Fbuildroot%2Ftree%2Fpackage%2Flinux-
> >> tools%2Flinux-tool-
> >>
> cpupower.mk.in&data=05%7C02%7Cpeng.fan%40nxp.com%7C246da9
> >>
> 2d8b6243d138c808dd09e6d644%7C686ea1d3bc2b4c6fa92cd99c5c3
> >>
> 01635%7C0%7C0%7C638677609234547728%7CUnknown%7CTWFpb
> >>
> GZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJX
> >>
> aW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdat
> >>
> a=nL1YUl%2F07Vd8F0GpW7uRqdpZT74avOku1ox9N3%2FFkUg%3D&r
> >> eserved=0
> >>
> >> and after enabling verbose it becomes clear as to why, see below:
> >>
> >>   >>> linux-tools  Configuring
> >>   >>> linux-tools  Building
> >> GIT_DIR=.
> >> PATH="/local/users/fainelli/buildroot-
> >> upstream/output/arm/host/bin:/local/users/fainelli/buildroot-
> >>
> upstream/output/arm/host/sbin:/projects/firepath/tools/bin:/home/ff
> >>
> 944844/bin:/home/ff944844/.local/bin:/opt/stblinux/bin:/usr/local/sb
> >> in:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local
> >> /ga mes:/snap/bin:/opt/toolchains/metaware-vctools-0.4.1/bin/"
> >> /usr/bin/make -j97
> >> CROSS=/local/users/fainelli/buildroot-
> >> upstream/output/arm/host/bin/arm-linux-
> >> CPUFREQ_BENCH=false NLS=false LDFLAGS="-L.
> >> -L/local/users/fainelli/buildroot-
> upstream/output/arm/target/usr/lib"
> >> DEBUG=false V=1 -C
> >> /local/users/fainelli/buildroot-upstream/output/arm/build/linux-
> >> custom/tools
> >> cpupower
> >> mkdir -p power/cpupower && /usr/bin/make
> subdir=power/cpupower
> >> --no-print-directory -C power/cpupower cc -DVERSION=\"6.12.0\" -
> >> DPACKAGE=\"cpupower\"
> >> -DPACKAGE_BUGREPORT=\"linux-pm@...r.kernel.org\" -
> D_GNU_SOURCE -pipe
> >> -Wall -Wchar-subscripts -Wpointer-arith -Wsign- compare
> >> -Wno-pointer-sign -Wdeclaration-after-statement -Wshadow - Os
> >> -fomit-frame-pointer -fPIC -o lib/cpufreq.o -c lib/cpufreq.c
> >
> > You are building on an ARM host? Or you are cross compiling with cc
> is
> > actually arm gcc?
> 
> This is cross compiling targeting ARM, which is why CROSS is set to
> ../arm-linux-
> 
> >
> >>
> >> Here we use cc, aka host compiler, rather than $(CROSS)gcc as we
> >> should, so we are no longer cross compiling at all.
> >
> > I not understand. CROSS was set, but using cc to compile for host?
> 
> See below.
> 
> >
> >>
> >> The issue is the use of the lazy set if absent for *all* of CC, LD,
> >> AR, STRIP, RANLIB, rather than just for CROSS. The following fixes it
> for me:
> >>
> >> diff --git a/tools/power/cpupower/Makefile
> >> b/tools/power/cpupower/Makefile index
> >> 175004ce44b2..96bb1e5f3970 100644
> >> --- a/tools/power/cpupower/Makefile
> >> +++ b/tools/power/cpupower/Makefile
> >> @@ -87,11 +87,11 @@ INSTALL_SCRIPT = ${INSTALL} -m 644
> >>    # to something more interesting, like "arm-linux-".  If you want
> >>    # to compile vs uClibc, that can be done here as well.
> >>    CROSS ?= #/usr/i386-linux-uclibc/usr/bin/i386-uclibc-
> >> -CC ?= $(CROSS)gcc
> >> -LD ?= $(CROSS)gcc
> >> -AR ?= $(CROSS)ar
> >> -STRIP ?= $(CROSS)strip
> >> -RANLIB ?= $(CROSS)ranlib
> >> +CC = $(CROSS)gcc
> >> +LD = $(CROSS)gcc
> >> +AR = $(CROSS)ar
> >> +STRIP = $(CROSS)strip
> >> +RANLIB = $(CROSS)ranlib
> >
> > The ? is just allow to override CC/LD/AR.., so in your env, CC is set,
> > but should not be used for cpupower compling?
> 
> Adding debug to show the origin of the CC variable shows the following:
> 
> CROSS=/local/users/fainelli/buildroot-
> upstream/output/arm/host/bin/arm-linux-
> CC origin is (default) and value is (cc) LD origin is (default) and value is
> (ld) CC=cc LD=ld AR=ar STRIP= RANLIB=


How about
CROSS ?= #/usr/i386-linux-uclibc/usr/bin/i386-uclibc-
ifneq ($(CROSS), )
CC = $(CROSS)gcc
LD = $(CROSS)gcc
AR = $(CROSS)ar
STRIP = $(CROSS)strip
RANLIB = $(CROSS)ranlib
else
CC ?= $(CROSS)gcc
LD ?= $(CROSS)gcc
AR ?= $(CROSS)ar
STRIP ?= $(CROSS)strip
RANLIB ?= $(CROSS)ranlib
Endif

Thanks,
Peng.

> 
> See
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2F
> www.gnu.org%2Fsoftware%2Fmake%2Fmanual%2Fhtml_node%2FOrig
> in-Function.html%23Origin-
> Function&data=05%7C02%7Cpeng.fan%40nxp.com%7C02c643288e1e
> 456e69e108dd0a4e58d7%7C686ea1d3bc2b4c6fa92cd99c5c301635%
> 7C0%7C0%7C638678053808856433%7CUnknown%7CTWFpbGZsb3d8
> eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiI
> sIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=L4xd4j
> ijUJXibguQnxUTzcAUA%2FGSUGUQzmA5FfVaaAQ%3D&reserved=0
> --
> Florian

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