Difference between revisions of "How to compile the device tree with the Developer Package"

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1 Purpose[edit]

This article explains how to update the boot chain (trusted mode) for a "custom" device tree.
In particular, STM32CubeMX can generate a "custom" device tree.

This article describes how to update the device tree compiled (DTB) part of the boot binaries.

2 Rationale[edit]

There are various rationale for using a custom device tree, such as:

  • the description of a new and private board
  • the swapping of some internal peripherals from Cortex®-M side to Cortex-A side (or the opposite)

3 Prerequisites[edit]

Info white.png Information
Even if STMicroelectronics strongly recommends to use a Linux® environment, the steps described in this article can be executed in a WSL2 (Windows Sub-system Linux 2) environment.

Compiling a new device tree means updating three software components belonging to the complete boot chain (trusted mode), Trusted Firmware A (TF-A), u-boot, and Linux kernel.


The material required to update the above software components is the following:

  • Starter package:
    • the flashlayout as well as the images to flash, provided within the en.FLASH-stm32mp1-openstlinux<YY>-<MM>-<DD>.tar.xz file (download it from st.com)
  • Developer package:
    • the component sources and patches, provided within the en.SOURCES-stm32mp1-openstlinux-<YY>-<MM>-<DD>.tar.xz file (download it from st.com)
    • the SDK toolchain, provided within the en.SDK-x86_64-stm32mp1-openstlinux-<YY>-<MM>-<DD>.tar.xz file (download it from st.com)
  • the STM32CubeProgrammer, which is the tool used to flash the images and binaries into the target.


  • Custom device tree sources:
    • In the rest of this document, we assume that the custom device tree is generated by STM32CubeMX and stored in a MyDeviceTree_fromCubeMX.tar.xz tarball with following file tree:
MyDeviceTree_fromCubeMX
|-- kernel
|   |-- stm32mp157c-mydevicetree-mx.dts
|-- tf-a
|  |-- stm32mp157c-mydevicetree-mx.dts
|  |-- stm32mp157c-mydevicetree-mx-fw-config.dts
|  |-- stm32mp15-mx.dtsi
|-- u-boot
|  |-- stm32mp157c-mydevicetree-mx.dts
|  |-- stm32mp157c-mydevicetree-mx-u-boot.dtsi
|  |-- stm32mp15-mx.dtsi


4 Preparing your environment[edit]

It is recommended to organize the numerous inputs described in #Prerequisites in your environment.
First create a dedicated WORKDIR under your HOME folder and copy there all the inputs listed in #Prerequisites:

cd $HOME
mkdir WORKDIR
cd WORKDIR
export WORKDIR="$PWD"
tar --strip-components=1 -xf <FLASH-st-image-weston-openstlinux-weston-stm32mp1.tar.xz> -C $WORKDIR/
tar --strip-components=1 -xf <SOURCES-st-image-weston-openstlinux-weston-stm32mp1.tar.xz> -C $WORKDIR/
tar --strip-components=1 -xf <SDK-st-image-weston-openstlinux-weston-stm32mp1.tar.xz> -C $WORKDIR/
tar xf <MyDeviceTree_fromCubeMX.tar.xz> -C $WORKDIR/

Then proceed with the SDK installation.


The commands described in the rest of the document must be run in an SDK environment context: (Starting_up_the_SDK).

5 Updating the kernel device tree[edit]

Since 'extlinux.conf' explicitly points to the DTB, just update the kernel device tree by replacing the DTB file of the '/boot' partition. The path used must be something like '/boot/<devicetree>.dtb'.

The following chapters describe the procedure to generate and copy the new DTB into the target.

5.1 Kernel : unpack and patch sources[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/linux-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of kernel

Run the following command into a shell:

pushd $WORKDIR
mkdir -p kernel
tar xf sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/linux-*.tar.xz -C kernel
mv kernel/linux-* kernel/kernel-sources/
pushd kernel/kernel-sources/
for p in $(ls -1 ../../sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/*.patch); do patch -p1 < $p; done
popd
popd

5.2 Kernel : copy the DTS into the source code[edit]

pushd $WORKDIR
cp -r MyDeviceTree_fromCubeMX/kernel/* kernel/kernel-sources/arch/arm/boot/dts/
popd

5.3 Kernel : regenerate the kernel DTB[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/linux-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of kernel
pushd $WORKDIR/kernel/kernel-sources
make ARCH=arm O="$PWD/../build" multi_v7_defconfig fragment*.config
for f in `ls -1 ../../sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/fragment*.config`; do scripts/kconfig/merge_config.sh -m -r -O $PWD/../build $PWD/../build/.config $f; done
yes "" | make ARCH=arm oldconfig O="$PWD/../build"
make stm32mp157c-mydevicetree-mx.dtb LOADADDR=0xC2000040 O="$PWD/../build"
popd
ls -l $WORKDIR/kernel/build/arch/arm/boot/dts/stm32mp157c-mydevicetree-mx.dtb

5.4 Kernel : copy the DTB into bootfs[edit]

First of all #Updating bootfs with the new DTB so that it is taken it into account at the next boot of the target.

Then, if needed, #Updating extlinux for the target according to this new DTB filename. This is only required if the filename of the generated DTB is different from the one used by extlinux to boot.

6 Updating the TF-A device tree[edit]

To update the TF-A device tree, replace the DTB part of the TF-A binary.
The TF-A binary allocates a 'fixed' area for the DTB, just after the 'mkimage" headers. If the DTB is smaller than the reserved area, the remaining memory is padded with zero.

Below the procedure to generate TF-A with a new DTB and then flash it on the target:

6.1 TF-A : unpack and patch sources[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of tf-a
pushd $WORKDIR
pushd sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*
mkdir -p tf-a-sources
tar xf tf-a-stm32mp-[0-9]*.tar.* --one-top-level=tf-a-sources --strip-components=1
pushd tf-a-sources
for p in `ls -1 ../*.patch`; do patch -p1 < $p; done
popd
popd

6.2 TF-A : copy the DTS into the source code[edit]

pushd $WORKDIR
cp -r MyDeviceTree_fromCubeMX/tf-a/* sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*/tf-a-sources/fdts/
popd

6.3 TF-A : regenerate TF-A[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of tf-a


pushd $WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*/tf-a-sources
export FIP_DEPLOYDIR_ROOT=$PWD/../../FIP_artifacts
make -f ../Makefile.sdk TF_A_DEVICETREE=<devicetree_name> FIP_CONFIG=" trusted" FIP_BL32_CONF="tfa," TF_A_CONFIG="trusted emmc nand nor sdcard uart usb" DEPLOYDIR=$FIP_DEPLOYDIR_ROOT/arm-trusted-firmware stm32
<device tree> : is the device tree just copied, i.e.: stm32mp157c-mydevicetree-mx
DEPLOYDIR is the path where intermediate binaries of tf-a should be deployed (requiered by fip-tools to generate fip image)
popd

7 Updating the u-boot device tree[edit]

To update the u-boot device tree, replace the DTB part of the u-boot binary.
Adding a new device tree to the u-boot source code forces the Makefile to regenerate a new u-boot.stm32 containing the new DTS.
The following chapters describe the procedure to update the u-boot device tree.

7.1 U-boot : unpack and patch sources[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of u-boot
pushd $WORKDIR
pushd sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-[0-9]*
tar xf u-boot-stm32mp-[0-9]*.tar.* --one-top-level=u-boot-sources --strip-components=1
pushd u-boot-sources
for p in `ls -1 ../*.patch`; do patch -p1 < $p; done
popd
popd

7.2 U-boot : copy the DTS in the u-boot source code[edit]

pushd $WORKDIR
cp MyDeviceTree_fromCubeMX/u-boot/* sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-[0-9]*/u-boot-sources/arch/arm/dts/
popd

7.3 U-boot : regenerate fip image within new u-boot[edit]

Info white.png Information
The procedure below is an extract of the README.HOW_TO.txt file which is available in $WORKDIR/sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-*. Please notice a grep "$>" README.HOW_TO.txt describes the few commands needed to build the artifact of u-boot
pushd $WORKDIR/u-boot/u-boot-sources
make stm32mp15_<config>_defconfig
<config> : could be trusted or basic according the boot type
make -f ../Makefile.sdk DEVICE_TREE=<device tree> DEPLOYDIR=$FIP_DEPLOYDIR_ROOT/u-boot FIP_CONFIG=" trusted" FIP_BL32_CONF="tfa," all
<device tree> : is the device tree just copied, i.e.: stm32mp157c-mydevicetree-mx
popd

7.4 U-boot : copy the u-boot into the target[edit]

  • Because of 'extlinux' and before flashing the new fip image, make sure #Updating extlinux is compliant with the 'compatible' value in the DTS file.

8 Update methods[edit]

  • Then flash the u-boot.stm32 into the 'ssbl' partition of the target using STM32CubeProgrammer.

8 Update methods[edit]

8.1 Updating extlinux[edit]

8.1.1 extlinux basics[edit]

extlinux describes how u-boot boots. Updating extlinux consists in updating the extlinux.conf:

  • In case of an DK-2 board booting from the sdcard. A stm32mp157c-dk2_extlinux.conf file is located in /boot/mmc0_extlinux/,
  • otherwise if there is no specific extlinux.conf for your board then the extlinux.conf is taking into account.

extlinux.conf is the description of a boot menu with one or several entries; 'DEFAULT' selects the default entry.
Below an example of extlinux.conf:

menu title Select the boot mode
MENU BACKGROUND ../splash.bmp
TIMEOUT 5
DEFAULT stm32mp157c-mydevicetree-mx
LABEL stm32mp157c-dk2-sdcard
        KERNEL /uImage
        FDTDIR /
        APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
LABEL stm32mp157c-dk2-a7-examples-sdcard
        KERNEL /uImage
        FDT /stm32mp157c-dk2-a7-examples.dtb
        APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
LABEL stm32mp157c-dk2-m4-examples-sdcard
        KERNEL /uImage
        FDT /stm32mp157c-dk2-m4-examples.dtb
        APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
LABEL stm32mp157c-mydevicetree-mx
       KERNEL /uImage
       FDT /stm32mp157c-mydevicetree-mx.dtb
       APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200

Please update/add the highlighted lines according to what have been compiled in chapter 5, 6 and/or 7:

  • DEFAULT: This is the default 'LABEL' to boot
  • LABEL : The entry 'LABEL' is the value of 'compatible' of the DTS file compiled with u-boot.
    The 'compatible' value is at head of the DTS file and looks like : "st,stm32mp157c-mydevicetree-mx"
  • FDT : The path from /boot of the kernel DTB to use

8.2 Updating bootfs[edit]

There are two methods to update bootfs

  • On an up and running target
scp stm32mp157c-mydevicetree-mx.dtb root@<Target_IP>:/boot/
  • Directly into 'bootfs' image

You do not need to have a target up and running. Only the "st-image-bootfs-openstlinux-weston-stm32mp1.ext4" file is required. To modify an 'ext4' file, a loopback mount, avaible within any Linux Distribution (even through WSL2), is required:

mkdir -p $WORKING/bootfs
mount -o loop <st-image-bootfs-openstlinux-weston-stm32mp1.ext4> $WORKING/bootfs
##Then copy the new dtb file at the root of $WORKING/bootfs
umount $WORKING/bootfs
sync

Then use STM32CubeProgrammer to update the bootfs partiton

8.2.1 Updating extlinux[edit]

Updating 'extlinux' consists in modifying the extlinux.conf. There are two ways to do this:

  • On an up and running target

Open an ssh connection to the target or use a direct connection with a tty terminal. Then use an vi editor to modify the extlinux.conf file.

Do not forget to synchronize the file system before rebooting the target:
sync
  • Into 'bootfs' image directly

You do not need to have a target up and running. Only the "st-image-bootfs-openstlinux-weston-stm32mp1.ext4" file is required. To modify an 'ext4' file, a loopback mount tool, avaible in any Linux Distribution (even through WSL2), is needed:

mkdir -p $WORKING/bootfs
sudo mount -o loop <st-image-bootfs-openstlinux-weston-stm32mp1.ext4> $WORKING/bootfs
##Then edit the extlinux.conf file (for WSL2 use a 'Linux' type editor; vi, ...)
##Once extlinux.conf up-to-date, umount loopback and flash the bootfs into sdcard with STM32CubeProgrammer
==Purpose==
This article explains how to update the [[Boot_chain_overview|boot chain]] (trusted mode) for a "custom" device tree. <br/>

In particular, STM32CubeMX can generate a "custom" device tree.<br/>


This article describes how to update the device tree compiled (DTB) part of the boot binaries.

==Rationale==

There are various rationale for using a custom ''device tree'', such as:
* the description of a new and private board
* the swapping of some internal peripherals from Cortex<sup>&reg;</sup>-M side to Cortex-A side (or the opposite)

==Prerequisites==
{{Info|Even if STMicroelectronics strongly recommends to use a Linux<sup>&reg;</sup> environment, the steps described in this article can be executed in a [[PC_prerequisites#WSL2_-28experimental-29|WSL2]] (Windows Sub-system Linux 2) environment. }}

Compiling a new device tree means updating three software components belonging to the complete [[Boot_chain_overview|boot chain]] (trusted mode), Trusted Firmware A (TF-A), u-boot, and Linux kernel.<br/>


The material required to update the above software components is the following:
* '''[[Which STM32MPU Embedded Software Package better suits your needs#Starter_Package|Starter package]]''': 
** the flashlayout as well as the images to flash, provided within the '''en.FLASH-stm32mp1-openstlinux&lt;YY&gt;-&lt;MM&gt;-&lt;DD&gt;.tar.xz''' file (download it from [https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32-mpu-openstlinux-distribution/stm32mp1starter.html#get-software st.com])
* '''[[Which STM32MPU Embedded Software Package better suits your needs#Developer_Package|Developer package]]''': 
** the component sources and patches, provided within the '''en.SOURCES-stm32mp1-openstlinux-&lt;YY&gt;-&lt;MM&gt;-&lt;DD&gt;.tar.xz''' file (download it from [https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32-mpu-openstlinux-distribution/stm32mp1dev.html#get-software st.com])
** the SDK toolchain, provided within the '''en.SDK-x86_64-stm32mp1-openstlinux-&lt;YY&gt;-&lt;MM&gt;-&lt;DD&gt;.tar.xz''' file (download it from [https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32-mpu-openstlinux-distribution/stm32mp1dev.html#get-software st.com])
* the '''[[STM32CubeProgrammer]]''', which is the tool used to flash the images and binaries into the target. <br/>

* '''Custom device tree sources''':
** In the rest of this document, we assume that the custom device tree is generated by [[STM32CubeMX]] and stored in a ''MyDeviceTree_fromCubeMX.tar.xz'' tarball with following file tree:<pre>MyDeviceTree_fromCubeMX
|-- kernel
|   |-- stm32mp157c-mydevicetree-mx.dts
|-- tf-a
|  |-- stm32mp157c-mydevicetree-mx.dts
|  |-- stm32mp157c-mydevicetree-mx-fw-config.dts
|  |-- stm32mp15-mx.dtsi
|-- u-boot
|  |-- stm32mp157c-mydevicetree-mx.dts
|  |-- stm32mp157c-mydevicetree-mx-u-boot.dtsi
|  |-- stm32mp15-mx.dtsi</pre>
<br/>

* Make sure the hardware configuration described in '''[[PC_prerequisites#Linux PC]] has been executed''' (even with a  [[PC_prerequisites#WSL2_-28experimental-29|WSL2]] setup)

==Preparing your environment==
It is recommended to organize the numerous inputs described in [[#Prerequisites]] in your environment.<br/>

First create a dedicated ''WORKDIR'' under your ''HOME'' folder and copy there all the inputs listed in [[#Prerequisites]]:
:{{PC$}} cd $HOME
:{{PC$}} mkdir WORKDIR
:{{PC$}} cd WORKDIR
:{{PC$}} export WORKDIR="$PWD"
:{{PC$}} tar --strip-components=1 -xf {{HighlightParam|''<FLASH-st-image-weston-openstlinux-weston-stm32mp1.tar.xz>''}} -C $WORKDIR/
:{{PC$}} tar --strip-components=1 -xf {{HighlightParam|''<SOURCES-st-image-weston-openstlinux-weston-stm32mp1.tar.xz>''}} -C $WORKDIR/
:{{PC$}} tar --strip-components=1 -xf {{HighlightParam|''<SDK-st-image-weston-openstlinux-weston-stm32mp1.tar.xz>''}} -C $WORKDIR/
:{{PC$}} tar xf {{HighlightParam|''<MyDeviceTree_fromCubeMX.tar.xz>''}} -C $WORKDIR/

Then proceed with the [[Install_the_SDK#Run_the_SDK_installation_script|SDK installation]].

The commands described in the rest of the document must be run in an SDK environment context: ([[Install_the_SDK#Starting_up_the_SDK|Starting_up_the_SDK]]).

==Updating the kernel device tree ==
Since 'extlinux.conf' explicitly points to the DTB, just update the kernel device tree by replacing the DTB file of the '/boot' partition. The path used must be something like '/boot/<devicetree>.dtb'.

The  following chapters describe the procedure to generate and copy the new DTB into the target.
=== Kernel : unpack and patch sources ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/linux-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of kernel}}

Run the following command into a shell:
:{{PC$}} pushd $WORKDIR
:{{PC$}} mkdir -p kernel
:{{PC$}} tar xf sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/linux-*.tar.xz -C kernel
:{{PC$}} mv kernel/linux-* kernel/kernel-sources/
:{{PC$}} pushd kernel/kernel-sources/
:{{PC$}} for p in $(ls -1 ../../sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/*.patch); do patch -p1 < $p; done
:{{PC$}} popd
:{{PC$}} popd

=== Kernel : copy the DTS into the source code ===
:{{PC$}} pushd $WORKDIR
:{{PC$}} cp -r MyDeviceTree_fromCubeMX/kernel/* kernel/kernel-sources/arch/arm/boot/dts/
:{{PC$}} popd

=== Kernel : regenerate the kernel DTB ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/linux-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of kernel}}

:{{PC$}} pushd $WORKDIR/kernel/kernel-sources
:{{PC$}} make ARCH=arm O="$PWD/../build" multi_v7_defconfig fragment*.config
:{{PC$}} for f in `ls -1 ../../sources/arm-ostl-linux-gnueabi/linux-stm32mp-*/fragment*.config`; do scripts/kconfig/merge_config.sh -m -r -O $PWD/../build $PWD/../build/.config $f; done
:{{PC$}} yes "" | make ARCH=arm oldconfig O="$PWD/../build"
:{{PC$}} make stm32mp157c-mydevicetree-mx.dtb LOADADDR=0xC2000040 O="$PWD/../build"
:{{PC$}} popd
:{{PC$}} ls -l $WORKDIR/kernel/build/arch/arm/boot/dts/stm32mp157c-mydevicetree-mx.dtb

=== Kernel : copy the DTB into bootfs ===
First of all [[#Updating bootfs]] with the new DTB so that it is taken it into account at the next boot of the target.

Then, if needed, [[#Updating extlinux]] for the target according to this new DTB filename. This is only required if the filename of the generated DTB is different from the one used by extlinux to boot.

==Updating the TF-A device tree ==
To update the TF-A device tree, replace the DTB part of the TF-A binary.<br/>

The TF-A binary allocates a 'fixed' area for the DTB, just after the 'mkimage" headers. If the DTB is smaller than the reserved area, the remaining memory is padded with zero.

Below the procedure to generate TF-A with a new DTB and then flash it on the target:<br/>

=== TF-A : unpack and patch sources ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of tf-a}}

:{{PC$}} pushd $WORKDIR
:{{PC$}} pushd sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*
:{{PC$}} mkdir -p tf-a-sources
:{{PC$}} tar xf tf-a-stm32mp-[0-9]*.tar.* --one-top-level=tf-a-sources --strip-components=1
:{{PC$}} pushd tf-a-sources
:{{PC$}} for p in `ls -1 ../*.patch`; do patch -p1 < $p; done
:{{PC$}} popd
:{{PC$}} popd

=== TF-A : copy the DTS into the source code ===
:{{PC$}}  pushd $WORKDIR
:{{PC$}}  cp -r MyDeviceTree_fromCubeMX/tf-a/* sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*/tf-a-sources/fdts/
:{{PC$}}  popd

=== TF-A : regenerate TF-A ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of tf-a}}

:{{PC$}} pushd $WORKDIR/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-[0-9]*/tf-a-sources
:{{PC$}} export FIP_DEPLOYDIR_ROOT=$PWD/../../FIP_artifacts
:{{PC$}} make -f ../Makefile.sdk TF_A_DEVICETREE={{HighlightParam|''<devicetree_name>''}} FIP_CONFIG=" trusted" FIP_BL32_CONF="tfa," TF_A_CONFIG="trusted  emmc nand nor sdcard  uart usb" DEPLOYDIR=$FIP_DEPLOYDIR_ROOT/arm-trusted-firmware stm32
::''<device tree>'' : is the device tree just copied, i.e.: '''''stm32mp157c-mydevicetree-mx'''''
::''DEPLOYDIR'' is the path where intermediate binaries of tf-a should be deployed (requiered by fip-tools to generate fip image)
:{{PC$}} popd

== Updating the u-boot device tree ==
To update the u-boot device tree, replace the DTB part of the u-boot binary.<br/>

Adding a new device tree to the u-boot source code forces the Makefile to regenerate a new u-boot.stm32 containing the new DTS. <br/>

The following chapters describe the procedure to update the u-boot device tree.

=== U-boot : unpack and patch sources ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of u-boot}}

:{{PC$}} pushd $WORKDIR
:{{PC$}} pushd sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-[0-9]*
:{{PC$}} tar xf u-boot-stm32mp-[0-9]*.tar.* --one-top-level=u-boot-sources --strip-components=1
:{{PC$}} pushd u-boot-sources
:{{PC$}} for p in `ls -1 ../*.patch`; do patch -p1 < $p; done
:{{PC$}} popd
:{{PC$}} popd

=== U-boot : copy the DTS in the u-boot source code ===
:{{PC$}} pushd $WORKDIR
:{{PC$}} cp MyDeviceTree_fromCubeMX/u-boot/* sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-[0-9]*/u-boot-sources/arch/arm/dts/
:{{PC$}} popd

=== U-boot : regenerate fip image within new u-boot ===
{{Info|The procedure below is an extract of the README.HOW_TO.txt file which is available in ''$WORKDIR/sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-*''. Please notice a ''grep "$>" README.HOW_TO.txt'' describes the few commands needed to build the artifact of u-boot}}

:{{PC$}} pushd $WORKDIR/u-boot/u-boot-sources
:{{PC$}} make stm32mp15_''<config>''_defconfig
: ''<config>'' : could be ''trusted'' or ''basic'' according the boot type
:{{PC$}} make -f ../Makefile.sdk DEVICE_TREE={{HighlightParam|''<device tree>''}} DEPLOYDIR=$FIP_DEPLOYDIR_ROOT/u-boot  FIP_CONFIG=" trusted" FIP_BL32_CONF="tfa," all
: ''<device tree>'' : is the device tree just copied, i.e.: stm32mp157c-mydevicetree-mx
:{{PC$}} popd

=== U-boot : copy the u-boot into the target ===
* Because of 'extlinux' and before flashing the new ''fip image'', make sure [[#Updating extlinux]] is compliant with the 'compatible' value in the DTS file.<br/>


= Update methods =
* Then flash the u-boot.stm32 into the 'ssbl' partition of the target using [[STM32CubeProgrammer]].== 

= Update methods =
== Updating extlinux ==
=== extlinux basics ===
'''extlinux''' describes how u-boot boots. Updating '''extlinux''' consists in updating the extlinux.conf:
* In case of an DK-2 board booting from the sdcard. A '''stm32mp157c-dk2_extlinux.conf''' file is located in ''/boot/mmc0_extlinux/'',
* otherwise if there is no specific extlinux.conf for your board then the '''extlinux.conf''' is taking into account.

'''extlinux.conf''' is the description of a boot menu with one or several entries; 'DEFAULT' selects the default entry.<br/>

Below an example of '''extlinux.conf''':
 menu title Select the boot mode
 MENU BACKGROUND ../splash.bmp
 TIMEOUT 5
 {{red|{{highlight|DEFAULT}} stm32mp157c-mydevicetree-mx}}
 LABEL stm32mp157c-dk2-sdcard
         KERNEL /uImage
         FDTDIR /
         APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
 LABEL stm32mp157c-dk2-a7-examples-sdcard
         KERNEL /uImage
         FDT /stm32mp157c-dk2-a7-examples.dtb
         APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
 LABEL stm32mp157c-dk2-m4-examples-sdcard
         KERNEL /uImage
         FDT /stm32mp157c-dk2-m4-examples.dtb
         APPEND root=PARTUUID=e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console=ttySTM0,115200
 {{red|{{highlight|LABEL}} stm32mp157c-mydevicetree-mx
        KERNEL /uImage
        {{highlight|FDT}} /stm32mp157c-mydevicetree-mx.dtb
        APPEND root&#61;PARTUUID&#61;e91c4e10-16e6-4c0e-bd0e-77becf4a3582 rootwait rw console&#61;ttySTM0,115200}}

Please update/add the highlighted lines according to what have been compiled in chapter 5, 6 and/or 7:
* {{highlight|DEFAULT}}: This is the default 'LABEL' to boot
* {{highlight|LABEL}} : The entry 'LABEL' is the value of 'compatible' of the DTS file compiled with u-boot.
*: The 'compatible' value is at head of the DTS file and looks like : "st,stm32mp157c-mydevicetree-mx"
* {{highlight|FDT}} : The path from /boot of the kernel DTB to use

== Updating bootfs ==
There are two methods to update bootfs 
* <u>{{STDarkBlue|On an up and running target}}</u>

:{{PC$}} scp stm32mp157c-mydevicetree-mx.dtb root@{{HighlightParam|''<Target_IP>''}}:/boot/
* <u>{{STDarkBlue|Directly into 'bootfs' image}}</u>

You do not need to have a target up and running. Only the "st-image-bootfs-openstlinux-weston-stm32mp1.ext4" file is required.
To modify an 'ext4' file, a loopback mount, avaible within any Linux Distribution (even through [[PC_prerequisites#WSL2_-28experimental-29|WSL2]]), is required:
:{{PC$}} mkdir -p $WORKING/bootfs
:{{PC$}} mount -o loop {{HighlightParam|''&lt;st-image-bootfs-openstlinux-weston-stm32mp1.ext4&gt;''}} $WORKING/bootfs
:{{grey|##Then copy the new dtb file at the root of $WORKING/bootfs}}
:{{PC$}} umount $WORKING/bootfs
:{{PC$}} sync
Then use [[STM32CubeProgrammer]] to update the bootfs partiton

=== Updating extlinux ===
Updating 'extlinux' consists in modifying the extlinux.conf. There are two ways to do this:
* <u>{{STDarkBlue|On an up and running target}}</u>

Open an ssh connection to the target or use a direct connection with a tty terminal. Then use an vi editor to modify the extlinux.conf file.<br/>

:{{highlight| Do not forget to synchronize the file system before rebooting the target:}}
:{{Board$}} sync

* <u>{{STDarkBlue|Into 'bootfs' image directly}}</u>

You do not need to have a target up and running. Only the "st-image-bootfs-openstlinux-weston-stm32mp1.ext4" file is required.
To modify an 'ext4' file, a loopback mount tool, avaible in any Linux Distribution (even through [[PC_prerequisites#WSL2_-28experimental-29|WSL2]]), is needed:
:{{PC$}} mkdir -p $WORKING/bootfs
:{{PC$}} sudo mount -o loop {{HighlightParam|&lt;st-image-bootfs-openstlinux-weston-stm32mp1.ext4&gt;}} $WORKING/bootfs
:{{grey|##Then edit the extlinux.conf file (for WSL2 use a 'Linux' type editor; vi, ...)}}
:{{grey|##Once extlinux.conf up-to-date, umount loopback and flash the bootfs into sdcard with [[STM32CubeProgrammer]]}}
<noinclude>

[[Category:How to build software]]</noinclude>
Line 163: Line 163:
 
=== U-boot : copy the u-boot into the target ===
 
=== U-boot : copy the u-boot into the target ===
 
* Because of 'extlinux' and before flashing the new ''fip image'', make sure [[#Updating extlinux]] is compliant with the 'compatible' value in the DTS file.<br/>
 
* Because of 'extlinux' and before flashing the new ''fip image'', make sure [[#Updating extlinux]] is compliant with the 'compatible' value in the DTS file.<br/>
  +
* Then flash the u-boot.stm32 into the 'ssbl' partition of the target using [[STM32CubeProgrammer]].
   
 
= Update methods =
 
= Update methods =
 
* Then flash the u-boot.stm32 into the 'ssbl' partition of the target using [[STM32CubeProgrammer]].
 
 
== Updating extlinux ==
 
== Updating extlinux ==
 
=== extlinux basics ===
 
=== extlinux basics ===