[RFC] buildtar: add case for riscv architecture
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  • [RFC] buildtar: add case for riscv architecture
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Commit Message

Aurabindo Pillai Sept. 11, 2019, 7:07 a.m. UTC
Hi,

I would like to know if something extra needs to be done other than copying compressed kernel image, when making tar package for riscv architecture. Please see the attached patch.

--

Thanks and Regards,
Aurabindo Jayamohanan

Comments

Troy Benjegerdes Sept. 11, 2019, 9:05 a.m. UTC | #1
None of the available RiscV platforms that I’m aware of use compressed images, unless there are some new bootloaders I haven’t seen yet.


> On Sep 11, 2019, at 2:07 AM, Aurabindo Jayamohanan <mail@aurabindo.in> wrote:
> 
> Hi,
> 
> I would like to know if something extra needs to be done other than copying compressed kernel image, when making tar package for riscv architecture. Please see the attached patch.
> 
> --
> 
> Thanks and Regards,
> Aurabindo Jayamohanan
> <0001-buildtar-add-riscv-case.patch>_______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
Aurabindo Pillai Sept. 11, 2019, 12:54 p.m. UTC | #2
> None of the available RiscV platforms that I’m aware of use compressed images, unless there are some new bootloaders I haven’t seen yet.
>

I noticed that default build image is Image.gz, which is why I thought its a good idea to copy it into the tarball. Does such a copy not make sense at this point ?
Palmer Dabbelt Sept. 14, 2019, 12:59 p.m. UTC | #3
On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@aurabindo.in wrote:
>
>
>> None of the available RiscV platforms that I’m aware of use compressed images, unless there are some new bootloaders I haven’t seen yet.
>>
>
> I noticed that default build image is Image.gz, which is why I thought its a good idea to copy it into the tarball. Does such a copy not make sense at this point ?

Image.gz can't be booted directly: it's just Image that's been compressed with 
the standard gzip command.  A bootloader would have to decompress that image 
before loading it into memory, which requires extra bootloader support.  
Contrast that with the zImage style images (which are vmlinuz on x86), which 
are self-extracting and therefor require no bootloader support.  The examples 
for u-boot all use the "booti" command, which expects uncompressed images.  
Poking around I couldn't figure out a way to have u-boot decompress the images, 
but that applies to arm64 as well so I'm not sure if I'm missing something.

If I was doing this, I'd copy over arch/riscv/boot/Image and call it 
"/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to me 
because I'd expect vmlinuz to be a self-extracting compressed executable and 
not a raw gzip file.
Anup Patel Sept. 14, 2019, 1:05 p.m. UTC | #4
> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org <linux-kernel-
> owner@vger.kernel.org> On Behalf Of Palmer Dabbelt
> Sent: Saturday, September 14, 2019 6:30 PM
> To: mail@aurabindo.in
> Cc: Troy Benjegerdes <troy.benjegerdes@sifive.com>; Paul Walmsley
> <paul.walmsley@sifive.com>; aou@eecs.berkeley.edu; linux-
> riscv@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> kbuild@vger.kernel.org
> Subject: Re: [RFC] buildtar: add case for riscv architecture
> 
> On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@aurabindo.in wrote:
> >
> >
> >> None of the available RiscV platforms that I’m aware of use compressed
> images, unless there are some new bootloaders I haven’t seen yet.
> >>
> >
> > I noticed that default build image is Image.gz, which is why I thought its a
> good idea to copy it into the tarball. Does such a copy not make sense at this
> point ?
> 
> Image.gz can't be booted directly: it's just Image that's been compressed
> with the standard gzip command.  A bootloader would have to decompress
> that image before loading it into memory, which requires extra bootloader
> support.
> Contrast that with the zImage style images (which are vmlinuz on x86), which
> are self-extracting and therefor require no bootloader support.  The
> examples for u-boot all use the "booti" command, which expects
> uncompressed images.
> Poking around I couldn't figure out a way to have u-boot decompress the
> images, but that applies to arm64 as well so I'm not sure if I'm missing
> something.
> 
> If I was doing this, I'd copy over arch/riscv/boot/Image and call it
> "/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to
> me because I'd expect vmlinuz to be a self-extracting compressed
> executable and not a raw gzip file.

On the contrary, it is indeed possible to boot Image.gz directly using
U-Boot booti command so this patch would be useful.

Atish had got it working on U-Boot but he has deferred booti Image.gz
support due to few more dependent changes. May be he can share
more info.

Regards,
Anup
Palmer Dabbelt Sept. 14, 2019, 7:27 p.m. UTC | #5
On Sat, 14 Sep 2019 06:05:59 PDT (-0700), Anup Patel wrote:
> 
> 
>> -----Original Message-----
>> From: linux-kernel-owner@vger.kernel.org <linux-kernel-
>> owner@vger.kernel.org> On Behalf Of Palmer Dabbelt
>> Sent: Saturday, September 14, 2019 6:30 PM
>> To: mail@aurabindo.in
>> Cc: Troy Benjegerdes <troy.benjegerdes@sifive.com>; Paul Walmsley
>> <paul.walmsley@sifive.com>; aou@eecs.berkeley.edu; linux-
>> riscv@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
>> kbuild@vger.kernel.org
>> Subject: Re: [RFC] buildtar: add case for riscv architecture
>> 
>> On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@aurabindo.in wrote:
>> >
>> >
>> >> None of the available RiscV platforms that I’m aware of use compressed
>> images, unless there are some new bootloaders I haven’t seen yet.
>> >>
>> >
>> > I noticed that default build image is Image.gz, which is why I thought its a
>> good idea to copy it into the tarball. Does such a copy not make sense at this
>> point ?
>> 
>> Image.gz can't be booted directly: it's just Image that's been compressed
>> with the standard gzip command.  A bootloader would have to decompress
>> that image before loading it into memory, which requires extra bootloader
>> support.
>> Contrast that with the zImage style images (which are vmlinuz on x86), which
>> are self-extracting and therefor require no bootloader support.  The
>> examples for u-boot all use the "booti" command, which expects
>> uncompressed images.
>> Poking around I couldn't figure out a way to have u-boot decompress the
>> images, but that applies to arm64 as well so I'm not sure if I'm missing
>> something.
>> 
>> If I was doing this, I'd copy over arch/riscv/boot/Image and call it
>> "/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to
>> me because I'd expect vmlinuz to be a self-extracting compressed
>> executable and not a raw gzip file.
> 
> On the contrary, it is indeed possible to boot Image.gz directly using
> U-Boot booti command so this patch would be useful.
> 
> Atish had got it working on U-Boot but he has deferred booti Image.gz
> support due to few more dependent changes. May be he can share
> more info.

Oh, great.  I guess it makes sense to just put both in the tarball, then, as 
users will still need to use the Image format for now.

> 
> Regards,
> Anup
Aurabindo Pillai Sept. 17, 2019, 9:35 a.m. UTC | #6
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Sunday, September 15, 2019 12:57 AM, Palmer Dabbelt <palmer@sifive.com> wrote:

> On Sat, 14 Sep 2019 06:05:59 PDT (-0700), Anup Patel wrote:
>
> > > -----Original Message-----
> > > From: linux-kernel-owner@vger.kernel.org <linux-kernel-
> > > owner@vger.kernel.org> On Behalf Of Palmer Dabbelt
> > > Sent: Saturday, September 14, 2019 6:30 PM
> > > To: mail@aurabindo.in
> > > Cc: Troy Benjegerdes troy.benjegerdes@sifive.com; Paul Walmsley
> > > paul.walmsley@sifive.com; aou@eecs.berkeley.edu; linux-
> > > riscv@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> > > kbuild@vger.kernel.org
> > > Subject: Re: [RFC] buildtar: add case for riscv architecture
> > > On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@aurabindo.in wrote:
> > >
> > > > > None of the available RiscV platforms that I’m aware of use compressed
> > > > > images, unless there are some new bootloaders I haven’t seen yet.
> > > >
> > > > >
> > > >
> > > > I noticed that default build image is Image.gz, which is why I thought its a
> > > > good idea to copy it into the tarball. Does such a copy not make sense at this
> > > > point ?
> > >
> > > Image.gz can't be booted directly: it's just Image that's been compressed
> > > with the standard gzip command. A bootloader would have to decompress
> > > that image before loading it into memory, which requires extra bootloader
> > > support.
> > > Contrast that with the zImage style images (which are vmlinuz on x86), which
> > > are self-extracting and therefor require no bootloader support. The
> > > examples for u-boot all use the "booti" command, which expects
> > > uncompressed images.
> > > Poking around I couldn't figure out a way to have u-boot decompress the
> > > images, but that applies to arm64 as well so I'm not sure if I'm missing
> > > something.
> > > If I was doing this, I'd copy over arch/riscv/boot/Image and call it
> > > "/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to
> > > me because I'd expect vmlinuz to be a self-extracting compressed
> > > executable and not a raw gzip file.
> >
> > On the contrary, it is indeed possible to boot Image.gz directly using
> > U-Boot booti command so this patch would be useful.
> > Atish had got it working on U-Boot but he has deferred booti Image.gz
> > support due to few more dependent changes. May be he can share
> > more info.
>
> Oh, great. I guess it makes sense to just put both in the tarball, then, as
> users will still need to use the Image format for now.
>

Uncompressed vmlinux is already copied by default. This patch just adds the
Image.gz into the archive as vmlinuz. But as you said, since the name vmlinuz is
reserved for self extracting archives, should I keep the original name Image.gz ?
Palmer Dabbelt Sept. 20, 2019, 10:40 p.m. UTC | #7
On Tue, 17 Sep 2019 02:35:10 PDT (-0700), mail@aurabindo.in wrote:
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Sunday, September 15, 2019 12:57 AM, Palmer Dabbelt <palmer@sifive.com> wrote:
>
>> On Sat, 14 Sep 2019 06:05:59 PDT (-0700), Anup Patel wrote:
>>
>> > > -----Original Message-----
>> > > From: linux-kernel-owner@vger.kernel.org <linux-kernel-
>> > > owner@vger.kernel.org> On Behalf Of Palmer Dabbelt
>> > > Sent: Saturday, September 14, 2019 6:30 PM
>> > > To: mail@aurabindo.in
>> > > Cc: Troy Benjegerdes troy.benjegerdes@sifive.com; Paul Walmsley
>> > > paul.walmsley@sifive.com; aou@eecs.berkeley.edu; linux-
>> > > riscv@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
>> > > kbuild@vger.kernel.org
>> > > Subject: Re: [RFC] buildtar: add case for riscv architecture
>> > > On Wed, 11 Sep 2019 05:54:07 PDT (-0700), mail@aurabindo.in wrote:
>> > >
>> > > > > None of the available RiscV platforms that I’m aware of use compressed
>> > > > > images, unless there are some new bootloaders I haven’t seen yet.
>> > > >
>> > > > >
>> > > >
>> > > > I noticed that default build image is Image.gz, which is why I thought its a
>> > > > good idea to copy it into the tarball. Does such a copy not make sense at this
>> > > > point ?
>> > >
>> > > Image.gz can't be booted directly: it's just Image that's been compressed
>> > > with the standard gzip command. A bootloader would have to decompress
>> > > that image before loading it into memory, which requires extra bootloader
>> > > support.
>> > > Contrast that with the zImage style images (which are vmlinuz on x86), which
>> > > are self-extracting and therefor require no bootloader support. The
>> > > examples for u-boot all use the "booti" command, which expects
>> > > uncompressed images.
>> > > Poking around I couldn't figure out a way to have u-boot decompress the
>> > > images, but that applies to arm64 as well so I'm not sure if I'm missing
>> > > something.
>> > > If I was doing this, I'd copy over arch/riscv/boot/Image and call it
>> > > "/boot/image-${KERNELRELEASE}", as calling it vmlinuz is a bit confusing to
>> > > me because I'd expect vmlinuz to be a self-extracting compressed
>> > > executable and not a raw gzip file.
>> >
>> > On the contrary, it is indeed possible to boot Image.gz directly using
>> > U-Boot booti command so this patch would be useful.
>> > Atish had got it working on U-Boot but he has deferred booti Image.gz
>> > support due to few more dependent changes. May be he can share
>> > more info.
>>
>> Oh, great. I guess it makes sense to just put both in the tarball, then, as
>> users will still need to use the Image format for now.
>>
>
> Uncompressed vmlinux is already copied by default. This patch just adds the
> Image.gz into the archive as vmlinuz. But as you said, since the name vmlinuz is
> reserved for self extracting archives, should I keep the original name Image.gz ?

vmlinux is not the same as Image: vmlinux is an ELF file that can't be loaded 
directly by most bootloaders, Image is a mostly-flat binary with a small header 
that we're expecting can be booted by most bootloaders.

Patch
diff mbox series

From 86feb93c62daa61314df0bbe1a11272c23b1eadb Mon Sep 17 00:00:00 2001
From: Aurabindo Jayamohanan <mail@aurabindo.in>
Date: Thu, 5 Sep 2019 12:52:45 +0530
Subject: [PATCH] buildtar: add riscv case

Copy compressed kernel image into tarball root. Similar
action for both arm64 and riscv architectures.

Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
---
 scripts/package/buildtar | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/package/buildtar b/scripts/package/buildtar
index 2f66c81e4021..388d0fcbe8c2 100755
--- a/scripts/package/buildtar
+++ b/scripts/package/buildtar
@@ -105,10 +105,10 @@  case "${ARCH}" in
 			cp -v -- "${objtree}/vmlinux" "${tmpdir}/boot/vmlinux-${KERNELRELEASE}"
 		fi
 		;;
-	arm64)
+	arm64|riscv)
 		for i in Image.bz2 Image.gz Image.lz4 Image.lzma Image.lzo ; do
-			if [ -f "${objtree}/arch/arm64/boot/${i}" ] ; then
-				cp -v -- "${objtree}/arch/arm64/boot/${i}" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
+			if [ -f "${objtree}/arch/${ARCH}/boot/${i}" ] ; then
+				cp -v -- "${objtree}/arch/${ARCH}/boot/${i}" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
 				break
 			fi
 		done
-- 
2.23.0