[Buildroot] [PATCH] xenomai: move arch restriction to Cobalt core, no restriction for Mercury

[Buildroot] [PATCH] xenomai: move arch restriction to Cobalt core, no restriction for Mercury

[Thomas De Schampheleire]

From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>

Xenomai has two mutually exclusive cores:
- Cobalt: dual-kernel approach: patched kernel + userland
- Mercury: only userland

In the Cobalt core, not all architectures are supported. This is the source
of the existing ARCH_SUPPORTS variable.

In the Mercury core, there is no imposed architecture restriction.

Rename the XENOMAI_ARCH_SUPPORTS flag to XENOMAI_COBALT_ARCH_SUPPORTS and
move its check from the Xenomai package to the Cobalt core.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
---
 linux/Config.ext.in       | 4 ++--
 package/xenomai/Config.in | 5 ++---
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/linux/Config.ext.in b/linux/Config.ext.in
index acc8a04742..71d8e07c25 100644
--- a/linux/Config.ext.in
+++ b/linux/Config.ext.in
@@ -4,7 +4,7 @@ menu "Linux Kernel Extensions"
 # Xenomai
 config BR2_LINUX_KERNEL_EXT_XENOMAI
 	bool "Adeos/Xenomai Real-time patch"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	depends on !BR2_TOOLCHAIN_USES_MUSL
 	select BR2_PACKAGE_XENOMAI
@@ -34,7 +34,7 @@ config BR2_LINUX_KERNEL_EXT_XENOMAI_ADEOS_PATCH
 	  and verify that your kernel version in buildroot matches.
 
 comment "xenomai needs a uClibc or glibc toolchain w/ threads"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_TOOLCHAIN_USES_MUSL
 
 #-------------------------------------------------------------------------------
diff --git a/package/xenomai/Config.in b/package/xenomai/Config.in
index f3d8ea4baf..a2bb1ab679 100644
--- a/package/xenomai/Config.in
+++ b/package/xenomai/Config.in
@@ -1,4 +1,4 @@
-config BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+config BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	bool
 	default y
 	depends on BR2_i386 || BR2_x86_64 || (BR2_arm && !BR2_ARM_CPU_ARMV7M) || \
@@ -6,11 +6,9 @@ config BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
 
 comment "xenomai needs an glibc or uClibc toolchain w/ threads"
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_TOOLCHAIN_USES_MUSL
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
 
 config BR2_PACKAGE_XENOMAI
 	bool "Xenomai Userspace"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	# uses <error.h>, __WORDSIZE and bits/local_lim.h
 	depends on !BR2_TOOLCHAIN_USES_MUSL
@@ -67,6 +65,7 @@ config BR2_PACKAGE_XENOMAI_MERCURY
 
 config BR2_PACKAGE_XENOMAI_COBALT
 	bool "Cobalt"
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	help
 	  Select Cobalt core (dual kernel) for the Xenomai
 	  userspace. Use this if you use a Xenomai-patched
-- 
2.19.2

[Buildroot] [PATCH] xenomai: move arch restriction to Cobalt core, no restriction for Mercury

[Thomas Petazzoni]

On Mon, 21 Jan 2019 20:50:04 +0100
Thomas De Schampheleire <patrickdepinguin@gmail.com> wrote:

> From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
> 
> Xenomai has two mutually exclusive cores:
> - Cobalt: dual-kernel approach: patched kernel + userland
> - Mercury: only userland
> 
> In the Cobalt core, not all architectures are supported. This is the source
> of the existing ARCH_SUPPORTS variable.
> 
> In the Mercury core, there is no imposed architecture restriction.
> 
> Rename the XENOMAI_ARCH_SUPPORTS flag to XENOMAI_COBALT_ARCH_SUPPORTS and
> move its check from the Xenomai package to the Cobalt core.
> 
> Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
> ---
>  linux/Config.ext.in       | 4 ++--
>  package/xenomai/Config.in | 5 ++---
>  2 files changed, 4 insertions(+), 5 deletions(-)

The patch looks good, but it needs more testing. Because it lifts all
the architecture dependencies, one can now try to build Xenomai for
funky architectures/configurations, and it doesn't always work. For
example, building with our br-arm-cortex-m4-full configuration fails
with a pthread_atfork issue.

I think this requires running a test-pkg run to check a couple of
architectures/configurations.

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[Buildroot] [PATCH] xenomai: move arch restriction to Cobalt core, no restriction for Mercury

[Thomas De Schampheleire]

From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>

Xenomai has two mutually exclusive cores:
- Cobalt: dual-kernel approach: patched kernel + userland
- Mercury: only userland

In the Cobalt core, not all architectures are supported. This is the source
of the existing ARCH_SUPPORTS variable.

In the Mercury core, there is no imposed architecture restriction.

Rename the XENOMAI_ARCH_SUPPORTS flag to XENOMAI_COBALT_ARCH_SUPPORTS and
move its check from the Xenomai package to the Cobalt core.

Nevertheless, even for Mercury, there are some restrictions:
- pthread_atfork is used, which requires an MMU
- sync functions like __sync_sub_and_fetch and __sync_add_and_fetch are
  expected.

As the corresponding 'linux extension' selects Xenomai, we add the
MMU and sync dependencies there too. They may or may not already be covered
by XENOMAI_COBALT_ARCH_SUPPORTS flag.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
---
 linux/Config.ext.in       | 12 ++++++++----
 package/xenomai/Config.in | 11 +++++++----
 2 files changed, 15 insertions(+), 8 deletions(-)

v2:
- add MMU and SYNC_4 dependencies (tested with test-pkg on all toolchains)

diff --git a/linux/Config.ext.in b/linux/Config.ext.in
index acc8a04742..32dacbdf06 100644
--- a/linux/Config.ext.in
+++ b/linux/Config.ext.in
@@ -4,9 +4,11 @@ menu "Linux Kernel Extensions"
 # Xenomai
 config BR2_LINUX_KERNEL_EXT_XENOMAI
 	bool "Adeos/Xenomai Real-time patch"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
-	depends on BR2_TOOLCHAIN_HAS_THREADS
-	depends on !BR2_TOOLCHAIN_USES_MUSL
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
+	depends on BR2_USE_MMU # xenomai
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4 # xenomai
+	depends on BR2_TOOLCHAIN_HAS_THREADS # xenomai
+	depends on !BR2_TOOLCHAIN_USES_MUSL # xenomai
 	select BR2_PACKAGE_XENOMAI
 	help
 	  Xenomai is split in two parts: a kernel part and a userspace
@@ -34,7 +36,9 @@ config BR2_LINUX_KERNEL_EXT_XENOMAI_ADEOS_PATCH
 	  and verify that your kernel version in buildroot matches.
 
 comment "xenomai needs a uClibc or glibc toolchain w/ threads"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
+	depends on BR2_USE_MMU
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_TOOLCHAIN_USES_MUSL
 
 #-------------------------------------------------------------------------------
diff --git a/package/xenomai/Config.in b/package/xenomai/Config.in
index f3d8ea4baf..83ba8ca162 100644
--- a/package/xenomai/Config.in
+++ b/package/xenomai/Config.in
@@ -1,16 +1,18 @@
-config BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+config BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	bool
 	default y
 	depends on BR2_i386 || BR2_x86_64 || (BR2_arm && !BR2_ARM_CPU_ARMV7M) || \
 		BR2_powerpc
 
-comment "xenomai needs an glibc or uClibc toolchain w/ threads"
+comment "xenomai needs a glibc or uClibc toolchain w/ threads"
+	depends on BR2_USE_MMU
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_TOOLCHAIN_USES_MUSL
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
 
 config BR2_PACKAGE_XENOMAI
 	bool "Xenomai Userspace"
-	depends on BR2_PACKAGE_XENOMAI_ARCH_SUPPORTS
+	depends on BR2_USE_MMU
+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	# uses <error.h>, __WORDSIZE and bits/local_lim.h
 	depends on !BR2_TOOLCHAIN_USES_MUSL
@@ -67,6 +69,7 @@ config BR2_PACKAGE_XENOMAI_MERCURY
 
 config BR2_PACKAGE_XENOMAI_COBALT
 	bool "Cobalt"
+	depends on BR2_PACKAGE_XENOMAI_COBALT_ARCH_SUPPORTS
 	help
 	  Select Cobalt core (dual kernel) for the Xenomai
 	  userspace. Use this if you use a Xenomai-patched
-- 
2.19.2

[Buildroot] [PATCH] xenomai: move arch restriction to Cobalt core, no restriction for Mercury

[Thomas Petazzoni]

On Tue,  5 Feb 2019 17:09:59 +0100
Thomas De Schampheleire <patrickdepinguin@gmail.com> wrote:

> From: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
> 
> Xenomai has two mutually exclusive cores:
> - Cobalt: dual-kernel approach: patched kernel + userland
> - Mercury: only userland
> 
> In the Cobalt core, not all architectures are supported. This is the source
> of the existing ARCH_SUPPORTS variable.
> 
> In the Mercury core, there is no imposed architecture restriction.
> 
> Rename the XENOMAI_ARCH_SUPPORTS flag to XENOMAI_COBALT_ARCH_SUPPORTS and
> move its check from the Xenomai package to the Cobalt core.
> 
> Nevertheless, even for Mercury, there are some restrictions:
> - pthread_atfork is used, which requires an MMU
> - sync functions like __sync_sub_and_fetch and __sync_add_and_fetch are
>   expected.
> 
> As the corresponding 'linux extension' selects Xenomai, we add the
> MMU and sync dependencies there too. They may or may not already be covered
> by XENOMAI_COBALT_ARCH_SUPPORTS flag.
> 
> Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
> ---
>  linux/Config.ext.in       | 12 ++++++++----
>  package/xenomai/Config.in | 11 +++++++----
>  2 files changed, 15 insertions(+), 8 deletions(-)

Applied to master, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com