[Buildroot] [PATCH 1/2] toolchain: Fix the toolchain-wrapper to support more recent GCC versions

[Buildroot] [PATCH 1/2] toolchain: Fix the toolchain-wrapper to support more recent GCC versions

[Johannes Schmitz]

This fix is necessary for to build for MIPS, for example for the MIPS
XBurst architecture used on ci20 boards.

Signed-off-by: Johannes Schmitz <johannes.schmitz1@gmail.com>
---
 toolchain/toolchain-wrapper.c  | 10 ++++++++--
 toolchain/toolchain-wrapper.mk |  6 +++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c
index 2928ea4..dd3a25e 100644
--- a/toolchain/toolchain-wrapper.c
+++ b/toolchain/toolchain-wrapper.c
@@ -79,8 +79,14 @@ static char *predef_args[] = {
 #ifdef BR_OMIT_LOCK_PREFIX
 	"-Wa,-momit-lock-prefix=yes",
 #endif
-#ifdef BR_NO_FUSED_MADD
-	"-mno-fused-madd",
+#ifdef BR2_TOOLCHAIN_GCC_AT_LEAST_4_6
+	#ifdef BR_FP_CONTRACT_OFF
+		"-ffp-contract=off",
+	#endif
+#else
+	#ifdef BR_NO_FUSED_MADD
+		"-mno-fused-madd",
+	#endif
 #endif
 #ifdef BR_BINFMT_FLAT
 	"-Wl,-elf2flt",
diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk
index 7f72a0c..b7a4b9b 100644
--- a/toolchain/toolchain-wrapper.mk
+++ b/toolchain/toolchain-wrapper.mk
@@ -28,7 +28,11 @@ endif
 
 # Avoid FPU bug on XBurst CPUs
 ifeq ($(BR2_mips_xburst),y)
-TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD
+	ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_6),y)
+		TOOLCHAIN_WRAPPER_ARGS += -DBR_FP_CONTRACT_OFF
+	else
+		TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD
+	endif
 endif
 
 ifeq ($(BR2_CCACHE_USE_BASEDIR),y)
-- 
2.7.4

[Buildroot] [PATCH 2/2] board/ci20: Implement creation of a basic sdcard image for ci20

[Johannes Schmitz]

Add a genimage.cfg to create a working sdcard.img for the ci20 hardware.
We also need a uboot-env.txt to create the partition for the uboot
environment.

Update the board/ci20/readme.txt with the related information. Remove
the tftp netboot description from the readme as it is already to
complicated for a basic bootable example.

Signed-off-by: Johannes Schmitz <johannes.schmitz1@gmail.com>
---
 board/ci20/genimage.cfg  | 29 ++++++++++++++++++++++++++
 board/ci20/readme.txt    | 54 ++++++++++++++++++++++++++----------------------
 board/ci20/uboot-env.txt | 10 +++++++++
 configs/ci20_defconfig   | 11 ++++++++++
 4 files changed, 79 insertions(+), 25 deletions(-)
 create mode 100644 board/ci20/genimage.cfg
 create mode 100644 board/ci20/uboot-env.txt

diff --git a/board/ci20/genimage.cfg b/board/ci20/genimage.cfg
new file mode 100644
index 0000000..fa3e736
--- /dev/null
+++ b/board/ci20/genimage.cfg
@@ -0,0 +1,29 @@
+image sdcard.img {
+    hdimage {
+    }
+
+    partition uboot-spl {
+        in-partition-table = "no"
+        image = "u-boot-spl.bin"
+        offset = 512
+    }
+
+    partition uboot {
+        in-partition-table = "no"
+        image = "u-boot.img"
+        offset = 14k
+    }
+
+    partition uboot-env {
+        in-partition-table = "no"
+        image = "uboot-env.bin"
+        offset = 526k
+    }
+
+    partition rootfs {
+        partition-type = 0x83
+        image = "rootfs.ext4"
+        offset = 2M
+        size = 60M
+    }
+}
diff --git a/board/ci20/readme.txt b/board/ci20/readme.txt
index ca7bb52..71d5070 100644
--- a/board/ci20/readme.txt
+++ b/board/ci20/readme.txt
@@ -2,41 +2,45 @@
 * MIPS Creator CI20 *
 *********************
 
+Introduction
+============
+
 The 'ci20_defconfig' will create a root filesystem and a kernel image
 under the 'output/images/' directory. This document will try to explain how
 to use them in order to run Buildroot in the MIPS Creator CI20 board.
 
-Assuming you are at the U-Boot prompt of the MIPS Creator CI20, you have to
-load the generated kernel image by using the 'tftpboot' command. In
-order to do that, you will need to get the network working. Here you
-have the instructions to set the ip address, netmask and gateway:
+How to build it
+===============
+
+Configure Buildroot
+-------------------
+
+  $ make ci20_defconfig
+
+Build the rootfs
+----------------
+
+Note: you will need to have access to the network, since Buildroot will
+download the packages' sources.
 
-  setenv ipaddr x.x.x.x
-  setenv netmask x.x.x.x
-  setenv gatewayip x.x.x.x
+You may now build your rootfs with:
 
-Now you have to set the ip for the TFTP server you are going to load the
-kernel image from, and also the name of the kernel image file (we use
-'uImage' as a filename in this example):
+  $ make
 
-  setenv serverip x.x.x.x
-  setenv bootfile uImage
+(This may take a while, consider getting yourself a coffee ;-) )
 
-And finally load the kernel image:
+How to write the SD card
+========================
 
-  tftpboot
+Once the build process is finished you will have an image called
+"sdcard.img" in the output/images/ directory.
 
-Now you have to extract the generated root filesystem into a USB drive
-or SD-Card. Here you have the instructions to boot from the two of them.
-You have to choose the one your prefer:
+Make sure the SD card is not mounted then copy the bootable "sdcard.img" onto
+it with "dd":
 
-From USB
-  setenv bootargs console=ttyS4,115200 console=tty0 mem=256M at 0x0
-mem=768M at 0x30000000 root=/dev/sda1
+  $ sudo dd if=output/images/sdcard.img of=/dev/sdX
 
-From SD-Card
-  setenv bootargs console=ttyS4,115200 console=tty0 mem=256M at 0x0
-mem=768M at 0x30000000 root=/dev/mmcblk0p1
+Insert the SDcard into your ci20, and power it up. Your new system
+should come up now and start a console on the UART HEADER.
 
-And finally run this command to boot the board:
-  bootm
+see: https://elinux.org/CI20_Hardware#Dedicated_UART_header
diff --git a/board/ci20/uboot-env.txt b/board/ci20/uboot-env.txt
new file mode 100644
index 0000000..3093496
--- /dev/null
+++ b/board/ci20/uboot-env.txt
@@ -0,0 +1,10 @@
+baudrate=115200
+board_mfr=NP
+bootargs=console=ttyS4,115200 console=tty0 mem=256M at 0x0 mem=768M at 0x30000000 rootwait root=/dev/mmcblk0p1 devtmpfs.mount=1 ip=dhcp
+bootcmd=run ethargs; ext4load mmc 0:1 0x88000000 /boot/uImage; bootm 0x88000000
+bootdelay=1
+ethargs=env set bootargs ${bootargs}
+loads_echo=1
+stderr=eserial0,eserial4
+stdin=eserial0,eserial4
+stdout=eserial0,eserial4
diff --git a/configs/ci20_defconfig b/configs/ci20_defconfig
index 6de6394..f28dd4d 100644
--- a/configs/ci20_defconfig
+++ b/configs/ci20_defconfig
@@ -8,6 +8,10 @@ BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_3_18=y
 
 # system
 BR2_TARGET_GENERIC_GETTY_PORT="ttyS4"
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/ci20/genimage.cfg"
 
 # kernel
 BR2_LINUX_KERNEL=y
@@ -15,6 +19,7 @@ BR2_LINUX_KERNEL_CUSTOM_GIT=y
 BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/MIPS/CI20_linux.git"
 BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="7dff33297116643485ca37141d804eddd793e834"
 BR2_LINUX_KERNEL_DEFCONFIG="ci20"
+BR2_LINUX_KERNEL_INSTALL_TARGET=y
 
 # u-boot
 BR2_TARGET_UBOOT=y
@@ -26,3 +31,9 @@ BR2_TARGET_UBOOT_CUSTOM_REPO_VERSION="dd3c1b95dac7d10b2ca5806f65e5c1050d7dd0fa"
 BR2_TARGET_UBOOT_FORMAT_IMG=y
 BR2_TARGET_UBOOT_SPL=y
 BR2_TARGET_UBOOT_SPL_NAME="spl/u-boot-spl.bin"
+BR2_TARGET_UBOOT_ENVIMAGE=y
+BR2_TARGET_UBOOT_ENVIMAGE_SOURCE="board/ci20/uboot-env.txt"
+BR2_TARGET_UBOOT_ENVIMAGE_SIZE="32768"
+
+# host
+BR2_PACKAGE_HOST_GENIMAGE=y
-- 
2.7.4

[Buildroot] [PATCH 2/2] board/ci20: Implement creation of a basic sdcard image for ci20

[Thomas Petazzoni]

Hello,

On Tue,  9 Jan 2018 17:08:28 +0100, Johannes Schmitz wrote:
> Add a genimage.cfg to create a working sdcard.img for the ci20 hardware.
> We also need a uboot-env.txt to create the partition for the uboot
> environment.
> 
> Update the board/ci20/readme.txt with the related information. Remove
> the tftp netboot description from the readme as it is already to
> complicated for a basic bootable example.
> 
> Signed-off-by: Johannes Schmitz <johannes.schmitz1@gmail.com>
> ---
>  board/ci20/genimage.cfg  | 29 ++++++++++++++++++++++++++
>  board/ci20/readme.txt    | 54 ++++++++++++++++++++++++++----------------------
>  board/ci20/uboot-env.txt | 10 +++++++++
>  configs/ci20_defconfig   | 11 ++++++++++
>  4 files changed, 79 insertions(+), 25 deletions(-)
>  create mode 100644 board/ci20/genimage.cfg
>  create mode 100644 board/ci20/uboot-env.txt

Applied to master, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH 1/2] toolchain: Fix the toolchain-wrapper to support more recent GCC versions

[Thomas Petazzoni]

Hello,

On Tue,  9 Jan 2018 17:08:27 +0100, Johannes Schmitz wrote:
> This fix is necessary for to build for MIPS, for example for the MIPS
> XBurst architecture used on ci20 boards.
> 
> Signed-off-by: Johannes Schmitz <johannes.schmitz1@gmail.com>

This is a bit short on explanation. Can you explain what it is fixing?
Why is -mno-fused-madd no longer sufficient in recent gcc versions?

The commit title is also not quite good, it doesn't mention that it's
MIPS-related. Perhaps:

toolchain: use -ffp-contract=off on MIPS XBust in the wrapper when needed

> diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c
> index 2928ea4..dd3a25e 100644
> --- a/toolchain/toolchain-wrapper.c
> +++ b/toolchain/toolchain-wrapper.c
> @@ -79,8 +79,14 @@ static char *predef_args[] = {
>  #ifdef BR_OMIT_LOCK_PREFIX
>  	"-Wa,-momit-lock-prefix=yes",
>  #endif
> -#ifdef BR_NO_FUSED_MADD
> -	"-mno-fused-madd",
> +#ifdef BR2_TOOLCHAIN_GCC_AT_LEAST_4_6

This condition is not needed, because toolchain-wrapper.mk is already
taking care of passing BR_NO_FUSED_MADD or BR2_FP_CONTRACT_OFF.

> +	#ifdef BR_FP_CONTRACT_OFF
> +		"-ffp-contract=off",
> +	#endif
> +#else
> +	#ifdef BR_NO_FUSED_MADD
> +		"-mno-fused-madd",
> +	#endif
>  #endif
>  #ifdef BR_BINFMT_FLAT
>  	"-Wl,-elf2flt",
> diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk
> index 7f72a0c..b7a4b9b 100644
> --- a/toolchain/toolchain-wrapper.mk
> +++ b/toolchain/toolchain-wrapper.mk
> @@ -28,7 +28,11 @@ endif
>  
>  # Avoid FPU bug on XBurst CPUs
>  ifeq ($(BR2_mips_xburst),y)
> -TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD
> +	ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_6),y)
> +		TOOLCHAIN_WRAPPER_ARGS += -DBR_FP_CONTRACT_OFF
> +	else
> +		TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD
> +	endif

Please don't indent lines. That's the Buildroot convention.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com