* [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures
@ 2020-09-24 12:22 Thomas Petazzoni
2020-09-24 12:22 ` [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv Thomas Petazzoni
2020-09-25 7:37 ` [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Yann E. MORIN
0 siblings, 2 replies; 6+ messages in thread
From: Thomas Petazzoni @ 2020-09-24 12:22 UTC (permalink / raw)
To: buildroot
Our Linux kernel compression options have the effect of enabling
CONFIG_KERNEL_{GZIP,LZMA,LZ4,...}. However, those configuration
options only exist on a subset of the CPU architectures, and it is
confusing to have such a choice visible when it in fact has no
effect. For example on ARM64, it has absolutely no effect, and the way
to create a compressed image is different, and the image is not
self-extractible.
So, we introduce a BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION to know which
architectures have compression support. Of course, it's never going to
be perfect as the set of architectures supporting compression might
change over time. But at least, it will allow us to hide this option
on architectures that do not at this point support compression.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
linux/Config.in | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/linux/Config.in b/linux/Config.in
index 49da2b81b2..9f2af6da5b 100644
--- a/linux/Config.in
+++ b/linux/Config.in
@@ -299,6 +299,22 @@ endchoice
# Kernel compression format
#
+# Indicates whether this architecture has support for built-in kernel
+# compression, i.e architectures that select one of
+# HAVE_KERNEL_{GZIP,LZMA,LZ4,LZO,XZ,UNCOMPRESSED}
+config BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION
+ bool
+ default y if BR2_arcle || BR2_arceb
+ default y if BR2_arm || BR2_armeb
+ default y if BR2_csky
+ default y if BR2_i386
+ default y if BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el
+ default y if BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le
+ default y if BR2_sh
+ default y if BR2_x86_64
+
+if BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION
+
choice
prompt "Kernel compression format"
help
@@ -326,6 +342,8 @@ config BR2_LINUX_KERNEL_ZSTD
endchoice
+endif
+
config BR2_LINUX_KERNEL_IMAGE_TARGET_NAME
string "Kernel image target name"
depends on BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv
2020-09-24 12:22 [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Thomas Petazzoni
@ 2020-09-24 12:22 ` Thomas Petazzoni
2020-09-25 2:31 ` Tian Yuanhao
2020-09-25 7:37 ` [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Yann E. MORIN
1 sibling, 1 reply; 6+ messages in thread
From: Thomas Petazzoni @ 2020-09-24 12:22 UTC (permalink / raw)
To: buildroot
Both arm64 and riscv allow generating a compressed Image.gz file, so
let's support that as a first class citizen.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
linux/Config.in | 4 ++++
linux/linux.mk | 2 ++
2 files changed, 6 insertions(+)
diff --git a/linux/Config.in b/linux/Config.in
index 9f2af6da5b..73b9c30b26 100644
--- a/linux/Config.in
+++ b/linux/Config.in
@@ -262,6 +262,10 @@ config BR2_LINUX_KERNEL_IMAGE
bool "Image"
depends on BR2_aarch64 || BR2_riscv
+config BR2_LINUX_KERNEL_IMAGE_GZ
+ bool "Image.gz"
+ depends on BR2_aarch64 || BR2_riscv
+
config BR2_LINUX_KERNEL_LINUX_BIN
bool "linux.bin"
depends on BR2_microblaze
diff --git a/linux/linux.mk b/linux/linux.mk
index e07e014d1e..133023f78c 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -201,6 +201,8 @@ else ifeq ($(BR2_LINUX_KERNEL_SIMPLEIMAGE),y)
LINUX_IMAGE_NAME = simpleImage.$(firstword $(LINUX_DTS_NAME))
else ifeq ($(BR2_LINUX_KERNEL_IMAGE),y)
LINUX_IMAGE_NAME = Image
+else ifeq ($(BR2_LINUX_KERNEL_IMAGE_GZ),y)
+LINUX_IMAGE_NAME = Image.gz
else ifeq ($(BR2_LINUX_KERNEL_LINUX_BIN),y)
LINUX_IMAGE_NAME = linux.bin
else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv
2020-09-24 12:22 ` [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv Thomas Petazzoni
@ 2020-09-25 2:31 ` Tian Yuanhao
0 siblings, 0 replies; 6+ messages in thread
From: Tian Yuanhao @ 2020-09-25 2:31 UTC (permalink / raw)
To: buildroot
On ?, 2020-09-24 at 14:22 +0200, Thomas Petazzoni wrote:
> Both arm64 and riscv allow generating a compressed Image.gz file, so
> let's support that as a first class citizen.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> ---
> ?linux/Config.in | 4 ++++
> ?linux/linux.mk??| 2 ++
> ?2 files changed, 6 insertions(+)
>
> diff --git a/linux/Config.in b/linux/Config.in
> index 9f2af6da5b..73b9c30b26 100644
> --- a/linux/Config.in
> +++ b/linux/Config.in
> @@ -262,6 +262,10 @@ config BR2_LINUX_KERNEL_IMAGE
> ? bool "Image"
> ? depends on BR2_aarch64 || BR2_riscv
> ?
> +config BR2_LINUX_KERNEL_IMAGE_GZ
> + bool "Image.gz"
> + depends on BR2_aarch64 || BR2_riscv
> +
> ?config BR2_LINUX_KERNEL_LINUX_BIN
> ? bool "linux.bin"
> ? depends on BR2_microblaze
> diff --git a/linux/linux.mk b/linux/linux.mk
> index e07e014d1e..133023f78c 100644
> --- a/linux/linux.mk
> +++ b/linux/linux.mk
> @@ -201,6 +201,8 @@ else ifeq ($(BR2_LINUX_KERNEL_SIMPLEIMAGE),y)
> ?LINUX_IMAGE_NAME = simpleImage.$(firstword $(LINUX_DTS_NAME))
> ?else ifeq ($(BR2_LINUX_KERNEL_IMAGE),y)
> ?LINUX_IMAGE_NAME = Image
> +else ifeq ($(BR2_LINUX_KERNEL_IMAGE_GZ),y)
> +LINUX_IMAGE_NAME = Image.gz
> ?else ifeq ($(BR2_LINUX_KERNEL_LINUX_BIN),y)
> ?LINUX_IMAGE_NAME = linux.bin
> ?else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
Tested-by: Tian Yuanhao <tianyuanhao@aliyun.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures
2020-09-24 12:22 [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Thomas Petazzoni
2020-09-24 12:22 ` [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv Thomas Petazzoni
@ 2020-09-25 7:37 ` Yann E. MORIN
2020-09-25 7:45 ` Thomas Petazzoni
1 sibling, 1 reply; 6+ messages in thread
From: Yann E. MORIN @ 2020-09-25 7:37 UTC (permalink / raw)
To: buildroot
Thomas, All,
On 2020-09-24 14:22 +0200, Thomas Petazzoni spake thusly:
> Our Linux kernel compression options have the effect of enabling
> CONFIG_KERNEL_{GZIP,LZMA,LZ4,...}. However, those configuration
> options only exist on a subset of the CPU architectures, and it is
> confusing to have such a choice visible when it in fact has no
> effect. For example on ARM64, it has absolutely no effect, and the way
> to create a compressed image is different, and the image is not
> self-extractible.
>
> So, we introduce a BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION to know which
> architectures have compression support. Of course, it's never going to
> be perfect as the set of architectures supporting compression might
> change over time. But at least, it will allow us to hide this option
> on architectures that do not at this point support compression.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> ---
> linux/Config.in | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/linux/Config.in b/linux/Config.in
> index 49da2b81b2..9f2af6da5b 100644
> --- a/linux/Config.in
> +++ b/linux/Config.in
> @@ -299,6 +299,22 @@ endchoice
> # Kernel compression format
> #
>
> +# Indicates whether this architecture has support for built-in kernel
> +# compression, i.e architectures that select one of
> +# HAVE_KERNEL_{GZIP,LZMA,LZ4,LZO,XZ,UNCOMPRESSED}
> +config BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION
> + bool
> + default y if BR2_arcle || BR2_arceb
> + default y if BR2_arm || BR2_armeb
> + default y if BR2_csky
> + default y if BR2_i386
> + default y if BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el
> + default y if BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le
> + default y if BR2_sh
> + default y if BR2_x86_64
> +
> +if BR2_LINUX_KERNEL_ARCH_HAS_COMPRESSION
So, if the arch does not support kernel image compression, we will have
none of the compression symbols defined, which means that, in linux.mk,
we would have:
104 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_GZIP) += CONFIG_KERNEL_GZIP
105 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZ4) += CONFIG_KERNEL_LZ4
106 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZMA) += CONFIG_KERNEL_LZMA
107 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZO) += CONFIG_KERNEL_LZO
108 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_XZ) += CONFIG_KERNEL_XZ
109 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_ZSTD) += CONFIG_KERNEL_ZSTD
[--SNIP--]
319 define LINUX_KCONFIG_FIXUP_CMDS
322 $(call KCONFIG_ENABLE_OPT,$(strip $(LINUX_COMPRESSION_OPT_y)))
But then, LINUX_COMPRESSION_OPT_y would be empty, so we'd call KCONFIG_ENABLE_OPT
with an empty string, which would expand to:
$(call KCONFIG_MUNGE_DOT_CONFIG, $(1), $(1)=y, $(2))
... and replacing the parameters would give (I'm pretty sure you'll see
where we're going now):
$(call KCONFIG_MUNGE_DOT_CONFIG, , =y, $(2))
When KCONFIG_MUNGE_DOT_CONFIG is expanded, we'd get:
$(SED) "/\\<$(strip $(1))\\>/d" $(call KCONFIG_DOT_CONFIG,$(3))
echo '$(strip $(2))' >> $(call KCONFIG_DOT_CONFIG,$(3))
... which would eventualy lead us to:
$(SED) "/\\<)\\>/d" /some/.config-file
echo '=y' >> /some/.config-file
And to be honest, I am not sure that last line would generate a fully
legit kconfig setting... ;-)
Of course, running 'make oldconfig' on that modified .config would drop
invalid lines, so you would not notivce the issue, but still this is not
correct...
Regards,
Yann E. MORIN.
> choice
> prompt "Kernel compression format"
> help
> @@ -326,6 +342,8 @@ config BR2_LINUX_KERNEL_ZSTD
>
> endchoice
>
> +endif
> +
> config BR2_LINUX_KERNEL_IMAGE_TARGET_NAME
> string "Kernel image target name"
> depends on BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
> --
> 2.26.2
>
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
| +33 561 099 427 `------------.-------: X AGAINST | \e/ There is no |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
'------------------------------^-------^------------------^--------------------'
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures
2020-09-25 7:37 ` [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Yann E. MORIN
@ 2020-09-25 7:45 ` Thomas Petazzoni
2020-09-25 8:14 ` Yann E. MORIN
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Petazzoni @ 2020-09-25 7:45 UTC (permalink / raw)
To: buildroot
Hello,
On Fri, 25 Sep 2020 09:37:58 +0200
"Yann E. MORIN" <yann.morin.1998@free.fr> wrote:
> So, if the arch does not support kernel image compression, we will have
> none of the compression symbols defined, which means that, in linux.mk,
> we would have:
>
> 104 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_GZIP) += CONFIG_KERNEL_GZIP
> 105 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZ4) += CONFIG_KERNEL_LZ4
> 106 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZMA) += CONFIG_KERNEL_LZMA
> 107 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_LZO) += CONFIG_KERNEL_LZO
> 108 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_XZ) += CONFIG_KERNEL_XZ
> 109 LINUX_COMPRESSION_OPT_$(BR2_LINUX_KERNEL_ZSTD) += CONFIG_KERNEL_ZSTD
> [--SNIP--]
> 319 define LINUX_KCONFIG_FIXUP_CMDS
> 322 $(call KCONFIG_ENABLE_OPT,$(strip $(LINUX_COMPRESSION_OPT_y)))
>
> But then, LINUX_COMPRESSION_OPT_y would be empty, so we'd call KCONFIG_ENABLE_OPT
> with an empty string, which would expand to:
>
> $(call KCONFIG_MUNGE_DOT_CONFIG, $(1), $(1)=y, $(2))
>
> ... and replacing the parameters would give (I'm pretty sure you'll see
> where we're going now):
>
> $(call KCONFIG_MUNGE_DOT_CONFIG, , =y, $(2))
>
> When KCONFIG_MUNGE_DOT_CONFIG is expanded, we'd get:
>
> $(SED) "/\\<$(strip $(1))\\>/d" $(call KCONFIG_DOT_CONFIG,$(3))
> echo '$(strip $(2))' >> $(call KCONFIG_DOT_CONFIG,$(3))
>
> ... which would eventualy lead us to:
>
> $(SED) "/\\<)\\>/d" /some/.config-file
> echo '=y' >> /some/.config-file
>
> And to be honest, I am not sure that last line would generate a fully
> legit kconfig setting... ;-)
>
> Of course, running 'make oldconfig' on that modified .config would drop
> invalid lines, so you would not notivce the issue, but still this is not
> correct...
Thanks for spotting this, I'll fix in v2. That being said, one can
notice that you're pointing out that this bogus =y line will be
dropped... just as equally as the bogus CONFIG_KERNEL_GZIP=y that we
have today gets dropped on arm64 and other architectures for which
those CONFIG_KERNEL_{GZIP,LZMA,LZ4,...} options don't exist :-)
Thomas
--
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures
2020-09-25 7:45 ` Thomas Petazzoni
@ 2020-09-25 8:14 ` Yann E. MORIN
0 siblings, 0 replies; 6+ messages in thread
From: Yann E. MORIN @ 2020-09-25 8:14 UTC (permalink / raw)
To: buildroot
Thomas, All,
On 2020-09-25 09:45 +0200, Thomas Petazzoni spake thusly:
> On Fri, 25 Sep 2020 09:37:58 +0200
> "Yann E. MORIN" <yann.morin.1998@free.fr> wrote:
[--SNIP--]
> > $(SED) "/\\<)\\>/d" /some/.config-file
> > echo '=y' >> /some/.config-file
> > And to be honest, I am not sure that last line would generate a fully
> > legit kconfig setting... ;-)
> > Of course, running 'make oldconfig' on that modified .config would drop
> > invalid lines, so you would not notivce the issue, but still this is not
> > correct...
> Thanks for spotting this, I'll fix in v2. That being said, one can
> notice that you're pointing out that this bogus =y line will be
> dropped... just as equally as the bogus CONFIG_KERNEL_GZIP=y that we
> have today gets dropped on arm64 and other architectures for which
> those CONFIG_KERNEL_{GZIP,LZMA,LZ4,...} options don't exist :-)
Yes, but an unknown symbol assignment is still valid syntax, and
silently discarded by kconfig, because that is the goal of running
oldconfig: assigning new symbols and dropping old ones.
But the '=y' is not even syntactically valid. kconfig is still lenient
about that, though (but it does warn, doesn't it?), but this is not a
reason to generate an invalid file.
Regards,
Yann E. MORIN.
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
| +33 561 099 427 `------------.-------: X AGAINST | \e/ There is no |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
'------------------------------^-------^------------------^--------------------'
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-09-25 8:14 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-24 12:22 [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Thomas Petazzoni
2020-09-24 12:22 ` [Buildroot] [PATCH 2/2] linux: support Image.gz on arm64 and riscv Thomas Petazzoni
2020-09-25 2:31 ` Tian Yuanhao
2020-09-25 7:37 ` [Buildroot] [PATCH 1/2] linux: show compression options only on some architectures Yann E. MORIN
2020-09-25 7:45 ` Thomas Petazzoni
2020-09-25 8:14 ` Yann E. MORIN
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