"How to create your own machine" in wiki and hits optee CFG_DRAM_SIZE bug

[0xedbea4]

Following the instructions here: https://wiki.st.com/stm32mpu/index.php/How_to_create_your_own_machine

And then making a trivial devicetree modification (enabling I2C5 output) fails to build on a fresh yocto install (via the "distribution package").  I'm beginning to port code from a DK2 to a custom board, and creating a transitional package.

The build slams right into the `flavorlist` mess in the optee make confs (specifically workspace/sources/optee-os-stm32mp/core/arch/arm/plat-stm32mp1/conf.mk) , ignoring the `CUBEMX_BOARD_DDR_SIZE = "512"` variables or anything else..

Very frustrating to see all these hardcoded filenames when yocto is very aware of the actual device tree in use at buildtime... looks like maybe the intended `CFG_EXT_DTS` escape hatch is broken?

Lots of previous posts have hit this problem, but on custom hardware, and with more significant DT changes.  I didn't touch the RAM or anything else other than have a default DK2 template MX project and then enable/"okay" I2C5.

[mmichala · Accepted solution]

Hello @0xedbea4 
I had similar issue:
1. I used STM32MP135F-DK board, opened it's project in CubeMX (via Board Selector) and generated Device Tree.

2. Then, during Yocto build, there was this CFG_DRAM_SIZE bug (missmatch).

As far as I understand it, optee sets CFG_DRAM_SIZE basing on DT name. And for unknown DT names (like mine, because it was generated from CubeMX) its sets default CFG_DRAM_SIZE to 1 GB. STM32MP135F-DK uses 512 MB and that value is defined in it's DT. So there is a missmatch and CFG_DRAM_SIZE bug occurs.

3. To fix it, I created a patch for optee, to set default CFG_DRAM_SIZE to 512 MB instead of 1 GB for unknown DT names. The patch is:

diff --git a/conf.mk.orginal b/conf.mk
index 2600f51..ec1e0e6 100644
--- a/core/arch/arm/plat-stm32mp1/conf.mk
+++ b/core/arch/arm/plat-stm32mp1/conf.mk
@@ -291,7 +291,7 @@ CFG_DRAM_SIZE    ?= 0x20000000
 endif
 
 CFG_DRAM_BASE    ?= 0xc0000000
-CFG_DRAM_SIZE    ?= 0x40000000
+CFG_DRAM_SIZE    ?= 0x20000000
 ifeq ($(CFG_STM32MP15)-$(CFG_WITH_PAGER),y-y)
 CFG_TZSRAM_START ?= 0x2ffc0000
 CFG_TZSRAM_SIZE  ?= 0x00040000

To apply it, I simply created a 

recipes-bsp/optee-os-stm32mp/optee-os-stm32mp_%.bbappend file like this:

FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"

SRC_URI:append := " \
	file://0001-fixed-CFG_DRAM_SIZE-in-conf-mk.patch \
"

[0xedbea4]

I was thinking something similar.  Many thanks for sharing your work!

Cheers

[0xedbea4]

There's an existing "./layers/meta-st/meta-st-stm32mp-addons/recipes-security/optee/optee-os-stm32mp_%.bbappend" in my dist-package project.  It is clearly TRYING to pick up the CUBEMX_BOARD_DDR_SIZE variable and setup the optee "conf.mk" file and definitely applied by bitbake correctly:

$ bitbatke-layers show-appends
...
=== Matched appended recipes ===
optee-os-stm32mp_4.0.0.bb:
  .../dist-package/layers/meta-st/meta-st-stm32mp-addons/recipes-security/optee/optee-os-stm32mp_%.bbappend

OUTPUT EDITED TO COMPLY WITH NDA

STM this file is not doing it's job.

# Configure recipe for CubeMX
inherit cubemx-stm32mp

python () {
    soc_package = (d.getVar('CUBEMX_SOC_PACKAGE') or "").split()
    if len(soc_package) > 1:
        bb.fatal('The CUBEMX_SOC_PACKAGE is initialized to: %s ! This var should only contains ONE package version' % soc_package)

    ddr_size = d.getVar('CUBEMX_BOARD_DDR_SIZE')
    if ddr_size is not None:
        size = int(ddr_size) * 1024 * 1024
        d.setVar('CUBEMX_BOARD_DDR_SIZE_HEXA', "0x%x" % size)
    else:
        d.setVar('CUBEMX_BOARD_DDR_SIZE_HEXA', "")
}

# manage paramater value
# DVFS OFF
CUBEMX_SOC_DVFS_OFF_option = "\
    ${@bb.utils.contains('CUBEMX_SOC_DVFS_OFF', '1', 'CFG_STM32MP1_CPU_OPP=n FG_SCMI_MSG_PERF_DOMAIN=n', '', d)} \
    "

EXTRA_OEMAKE += "${CUBEMX_SOC_PACKAGE_option} ${CUBEMX_BOARD_DDR_SIZE_option} ${CUBEMX_SOC_DVFS_OFF_option}"

# for generating external dt Makefile
SOC_OPTEE_CONFIG_SUPPORTED = "MP13 MP15 MP25 MP23"

ST_OPTEE_EXPORT_TA_REF_BOARD:stm32mpcommonmx = "${CUBEMX_DTB}.dts"
ST_OPTEE_EXPORT_TA_OEMAKE_EXTRA = ""
# ------------------------------------------------
# Generate optee conf for usage of EXTERNAL DT with cubemx devicetree
# ------------------------------------------------
autogenerate_conf_for_external_dt_cubemx() {
    [ "${ENABLE_CUBEMX_DTB}" -ne 1 ] && return;
    if [ -e "${STAGING_EXTDT_DIR}/${EXTDT_DIR_OPTEE}/conf.mk" ]; then
        [ "${CUBEMX_EXTDT_FORCE_MK}" -ne 1 ] && return
    fi
    echo "# SPDX-License-Identifier: BSD-2-Clause" > ${WORKDIR}/conf.external_dt
    echo "" >>  ${WORKDIR}/conf.external_dt

    dtb=$(echo ${STM32MP_DEVICETREE} | tr ' ' '\n' | uniq | tr '\n' ' ')
    for supported in ${SOC_OPTEE_CONFIG_SUPPORTED}; do
        echo "# ${supported} boards" >> ${WORKDIR}/conf.external_dt
        for soc in ${STM32MP_SOC_NAME}; do
            soc_maj=$(echo ${soc} | awk '{print toupper($0)}')
            [ "$(echo ${soc_maj} | grep -c ${supported})" -ne 1 ] && continue
            dtb_by_soc=""
            for devicetree in ${dtb}; do
                [ "$(echo ${devicetree} | grep -c ${soc})" -eq 1 ] && dtb_by_soc="${dtb_by_soc} ${devicetree}.dts"
            done
            echo "flavor_dts_file-${supported}-CUBEMX = ${dtb_by_soc}" >> ${WORKDIR}/conf.external_dt

            # add platform specific: package (with crypto or not), ddr size, HUK for mp15
            if ${@bb.utils.contains_any('CUBEMX_SOC_PACKAGE',[ 'C', 'F' ],'true','false',d)}; then
                echo "flavorlist-no_cryp = \$(flavor_dts_file-${supported}-CUBEMX)" >> ${WORKDIR}/conf.external_dt
            fi
            case ${CUBEMX_BOARD_DDR_SIZE} in
            512)
                echo "flavorlist-512M = \$(flavor_dts_file-${supported}-CUBEMX)" >> ${WORKDIR}/conf.external_dt
                ;;
            1024)
                echo "flavorlist-1G = \$(flavor_dts_file-${supported}-CUBEMX)" >> ${WORKDIR}/conf.external_dt
                ;;
            *)
                ;;
            esac
            if ${@bb.utils.contains('MACHINE_FEATURES','m33td','true','false',d)}; then
                echo "flavorlist-M33-TDCID = \$(flavor_dts_file-${supported}-CUBEMX)" >> ${WORKDIR}/conf.external_dt
            fi

            echo "flavorlist-${supported} += \$(flavor_dts_file-${supported}-CUBEMX)" >> ${WORKDIR}/conf.external_dt
        done
        echo "" >> ${WORKDIR}/conf.external_dt
    done
    echo "" >> ${WORKDIR}/conf.external_dt

    cp -f ${WORKDIR}/conf.external_dt ${STAGING_EXTDT_DIR}/${EXTDT_DIR_OPTEE}/conf.mk

}
python() {
    machine_overrides = d.getVar('MACHINEOVERRIDES').split(':')
    if "stm32mpcommonmx" in machine_overrides:
        d.appendVarFlag('do_configure', 'prefuncs', ' autogenerate_conf_for_external_dt_cubemx')
}

[0xedbea4]

A bit more detail since I've gotta stand this board up:

The bbappend file above DOES successfully manipulate CFG_DRAM_SIZE in the file ./dist-package/build-openstlinuxweston-stm32mp15-XXXXXXXX-mx/workspace/sources/optee-os-stm32mp/oe-workdir/build/opteemin-stm32mp157f-evon001-mx/conf.mk 

this is not the part of the optee build failing...  the "export-ta" target (which I know absolutely nothing about) is failing, becuase the variable is NOT set there by the configure script

from ./build-openstlinuxweston-stm32mp15-XXXXXXXXXXXX-mx/workspace/sources/optee-os-stm32mp/oe-workdir/build/export-ta/conf.mk

CFG_DRAM_BASE=0xc0000000

CFG_DRAM_SIZE=0x40000000

CFG_DRIVERS_ADC=y

bitbake do_compile fails:

```
.../dist-package/build-openstlinuxweston-stm32mp15-evon001-mx/tmp-glibc/work/stm32mp15_XXXXXXXXX_mx-ostl-linux-gnueabi/optee-os-stm32mp/4.0.0-stm32mp-r1/build/export-ta/core/tee-raw.bin
| Wrong CFG_DRAM_SIZE 1024MBytes, in device-tree: 512MBytes
| make: *** [core/arch/arm/plat-stm32mp1/link.mk:17: check_build_variables] Error 1
```

[0xedbea4]

ooff yeah I'm not messing with the "export-ta" [Trusted Application] stuff on the oe/yocto level... 

what does work is too modify line 30744 of `./layers/meta-st/meta-st-stm32mp/recipes-security/optee/optee-os/0001-4.0.0-stm32mp-r1.patch`

to the correct RAM size (0x20000000)