Re: Query about current practice of installing linux kernel header files

Re: Query about current practice of installing linux kernel header files

[vlse]

Sorry, I didn't received mail from Szabolcs Nagy to my inbox.

I am unable to understand the Makefile fully.

May you please correct me on this:

1) First musl include headers files are installed.
2) Then linux kernel header files are copied over.

Is this correct?

What about building busybox with musl-libc?
It needed few adapted headers of linux kernel as well as musl libc ones?

Veera
vlse
http://www.veera.biz

Re: Re: Query about current practice of installing linux kernel header files

[Szabolcs Nagy]

* vlse <vlse@veera.biz> [2017-01-06 20:11:18 +0530]:
> Sorry, I didn't received mail from Szabolcs Nagy to my inbox.

i forgot to cc you

> I am unable to understand the Makefile fully.
> 
> May you please correct me on this:
> 
> 1) First musl include headers files are installed.
> 2) Then linux kernel header files are copied over.
> 
> Is this correct?
> 

sorry i remembered incorrectly, the header install
order does not matter if you use staging + copy

(the problem is that the kernel install_headers
removes the include/scsi/ directory first which
contains libc headers so installing libc and
linux headers to the same place can break, but
if you copy the linux headers from a staging dir
then it works)

> What about building busybox with musl-libc?
> It needed few adapted headers of linux kernel as well as musl libc ones?

alpine linux applies the same kernel header patches that sabotage uses
http://git.alpinelinux.org/cgit/aports/plain/main/linux-headers/

i think since
http://git.musl-libc.org/cgit/musl/commit/?id=04983f2272382af92eb8f8838964ff944fbb8258
there is an easier (more upstreamable) fix for the linux headers

but i'm not sure how much of busybox is affected

Query about current practice of installing linux kernel header files

[vlse]

I have a query regarding installation of Linux kernel header files for use with musl while compiling programs requiring it. I studied musl-cross-make source files. From it I found that it applies the linux kernel patch "0001-archscripts.diff" to linux source. And basically it does the following:

1) $(MAKE) ARCH=$(LINUX_ARCH) O=somedir INSTALL_HDR_PATH=somedir/staged headers_install
2) find somedir/staged/include '(' -name .install -o -name ..install.cmd ')' -exec rm {} +
3) cp -R somedir/staged/include/* $(DESTDIR)$(OUTPUT)$(SYSROOT)/include

Is this correct?
Does it means we can use plain vanilla kernel source and install headers from it?
That is musl specific adaptation of Linux kernel sources & headers has been upstreamed.
No more any need of sabotage adapted linux kernel headers.
Please correct me.

vlse,

Veera

Re: Query about current practice of installing linux kernel header files

[Szabolcs Nagy]

* vlse <vlse@veera.biz> [2017-01-06 18:08:39 +0530]:
> I have a query regarding installation of Linux kernel header files for use with musl while compiling programs requiring it. I studied musl-cross-make source files. From it I found that it applies the linux kernel patch "0001-archscripts.diff" to linux source. And basically it does the following:
> 
> 1) $(MAKE) ARCH=$(LINUX_ARCH) O=somedir INSTALL_HDR_PATH=somedir/staged headers_install
> 2) find somedir/staged/include '(' -name .install -o -name ..install.cmd ')' -exec rm {} +
> 3) cp -R somedir/staged/include/* $(DESTDIR)$(OUTPUT)$(SYSROOT)/include
> 
> Is this correct?

i think this is not musl specific, but the linux kernel way
to install uapi (there are collisions with libc headers
so you need staging and copy to the destination in the right
order with respect to libc header install)

> Does it means we can use plain vanilla kernel source and install headers from it?

yes.

> That is musl specific adaptation of Linux kernel sources & headers has been upstreamed.
> No more any need of sabotage adapted linux kernel headers.
> Please correct me.

no, musl specific fixes are not upstreamed yet
but this only affects code that includes certain
linux headers as well as libc headers in the same
source files.