On 09.09.25 16:25, Jerome Forissier wrote:
> Hi Jan,
>
>
> On 8/24/25 09:18, Jan Kiszka wrote:
>> From: Jan Kiszka <[email protected]>
>>
>> As an eMMC block device image may consist of more than just the user
>> data partition, provide a helper script that can compose the image from
>> boot partitions, an RPMB partition and the user data image. The script
>> also does the required size validation and/or rounding.
>>
>> Signed-off-by: Jan Kiszka <[email protected]>
>> ---
>> scripts/mkemmc.sh | 185 ++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 185 insertions(+)
>> create mode 100755 scripts/mkemmc.sh
>>
>> diff --git a/scripts/mkemmc.sh b/scripts/mkemmc.sh
>> new file mode 100755
>> index 0000000000..5d40c2889b
>> --- /dev/null
>> +++ b/scripts/mkemmc.sh
>> @@ -0,0 +1,185 @@
>> +#!/bin/sh -e
>> +#
>> +# Create eMMC block device image from boot, RPMB and user data images
>> +#
>> +# Copyright (c) Siemens, 2025
>> +#
>> +# Authors:
>> +# Jan Kiszka <[email protected]>
>> +#
>> +# This work is licensed under the terms of the GNU GPL version 2.
>> +# See the COPYING file in the top-level directory.
>> +#
>> +
>> +usage() {
>> + echo "$0 [OPTIONS] USER_IMG[:SIZE] OUTPUT_IMG"
>> + echo ""
>> + echo "SIZE must be a power of 2. If no SIZE is specified, the size of
>> USER_ING will"
>> + echo "be used (rounded up)."
>> + echo ""
>> + echo "Supported options:"
>> + echo " -b BOOT1_IMG[:SIZE] Add boot partitions. SIZE must be
>> multiples of 128K. If"
>> + echo " no SIZE is specified, the size of
>> BOOT_IMG will be"
>
> the size of BOOT1_IMG
>
Thanks, fixed.
>> + echo " used (rounded up). BOOT1_IMG will be
>> stored in boot"
>> + echo " partition 1, and a boot partition 2 of
>> the same size"
>> + echo " will be created as empty (all zeros)
>> unless -B is"
>> + echo " specified as well."
>> + echo " -B BOOT2_IMG Fill boot partition 2 with BOOT2_IMG.
>> Must be combined"
>> + echo " with -b which is also defining the
>> partition size."
>> + echo " -r RPMB_IMG[:SIZE] Add RPMB partition. SIZE must be
>> multiples of 128K. If"
>> + echo " no SIZE is specified, the size of
>> RPMB_IMG will be"
>> + echo " used (rounded up)."
>> + echo " -h, --help This help"
>> + echo ""
>> + echo "All SIZE parameters support the units K, M, G. If SIZE is smaller
>> than the"
>> + echo "associated image, it will be truncated in the output image."
>> + exit "$1"
>> +}
>> +
>> +process_size() {
>> + if [ "${4#*:}" = "$4" ]; then
>> + if ! size=$(stat -L -c %s "$2" 2>/dev/null); then
>> + echo "Missing $1 image '$2'." >&2
>> + exit 1
>> + fi
>> + if [ "$3" = 128 ]; then
>> + size=$(( (size + 128 * 1024 - 1) & ~(128 * 1024 - 1) ))
>> + elif [ $(( size & (size - 1) )) -gt 0 ]; then
>> + n=0
>> + while [ "$size" -gt 0 ]; do
>> + size=$((size >> 1))
>> + n=$((n + 1))
>> + done
>> + size=$((1 << n))
>> + fi
>> + else
>> + value="${4#*:}"
>> + if [ "${value%K}" != "$value" ]; then
>> + size=${value%K}
>> + multiplier=1024
>> + elif [ "${value%M}" != "$value" ]; then
>> + size=${value%M}
>> + multiplier=$((1024 * 1024))
>> + elif [ "${value%G}" != "$value" ]; then
>> + size=${value%G}
>> + multiplier=$((1024 * 1024 * 1024))
>> + else
>> + size=$value
>> + multiplier=1
>> + fi
>> + if [ "$size" -eq "$size" ] 2>/dev/null; then
>> + size=$((size * multiplier))
>> + else
>> + echo "Invalid value '$value' specified for $2 image size." >&2
>> + exit 1
>> + fi
>> + if [ "$3" = 128 ]; then
>> + if [ $(( size & (128 * 1024 - 1) )) -ne 0 ]; then
>> + echo "The $2 image size must be multiples of 128K." >&2
>> + exit 1
>> + fi
>> + elif [ $(( size & (size - 1) )) -gt 0 ]; then
>> + echo "The %2 image size must be power of 2." >&2
>> + exit 1
>> + fi
>> + fi
>> + echo $size
>> +}
>> +
>> +userimg=
>> +outimg=
>> +bootimg1=
>> +bootimg2=/dev/zero
>> +bootsz=0
>> +rpmbimg=
>> +rpmbsz=0
>> +
>> +while [ $# -gt 0 ]; do
>> + case "$1" in
>> + -b)
>> + shift
>> + [ $# -ge 1 ] || usage 1
>> + bootimg1=${1%%:*}
>> + bootsz=$(process_size boot "$bootimg1" 128 "$1")
>> + shift
>> + ;;
>> + -B)
>> + shift
>> + [ $# -ge 1 ] || usage 1
>> + bootimg2=$1
>> + shift
>> + ;;
>> + -r)
>> + shift
>> + [ $# -ge 1 ] || usage 1
>> + rpmbimg=${1%%:*}
>> + rpmbsz=$(process_size RPMB "$rpmbimg" 128 "$1")
>> + shift
>> + ;;
>> + -h|--help)
>> + usage 0
>> + ;;
>> + *)
>> + if [ -z "$userimg" ]; then
>> + userimg=${1%%:*}
>> + usersz=$(process_size user "$userimg" 2 "$1")
>> + elif [ -z "$outimg" ]; then
>> + outimg=$1
>> + else
>> + usage 1
>> + fi
>> + shift
>> + ;;
>> + esac
>> +done
>> +
>> +[ -n "$outimg" ] || usage 1
>> +
>> +if [ "$bootsz" -gt $((32640 * 1024)) ]; then
>> + echo "Boot image size is larger than 32640K." >&2
>> + exit 1
>> +fi
>
> Should we warn if BOOT1_IMG and/or BOOT2_IMG are truncated as a result
> of $bootsz being too small? I can see how providing a larger size can be
> useful to be able to later extend the filesystem, but a smaller size is
> more likely to indicate an error I suppose?
Done, will be part of v4.
>
>> +if [ "$rpmbsz" -gt $((16384 * 1024)) ]; then
>> + echo "RPMB image size is larger than 16384K." >&2
>> + exit 1
>> +fi> +
>> +echo "Creating eMMC image"
>> +
>> +truncate "$outimg" -s 0
>> +pos=0
>> +
>> +if [ "$bootsz" -gt 0 ]; then
>> + echo " Boot partition 1 and 2: $((bootsz / 1024))K each"
>> + blocks=$(( bootsz / (128 * 1024) ))
>> + dd if="$bootimg1" of="$outimg" conv=sparse bs=128K count=$blocks \
>> + status=none
>> + dd if="$bootimg2" of="$outimg" conv=sparse bs=128K count=$blocks \
>> + seek=$blocks status=none
>> + pos=$((2 * bootsz))
>> +fi
>> +
>> +if [ "$rpmbsz" -gt 0 ]; then
>> + echo " RPMB partition: $((rpmbsz / 1024))K"
>> + blocks=$(( rpmbsz / (128 * 1024) ))
>> + dd if="$rpmbimg" of="$outimg" conv=sparse bs=128K count=$blocks \
>> + seek=$(( pos / (128 * 1024) )) status=none
>> + pos=$((pos + rpmbsz))
>> +fi
>> +
>> +if [ "$usersz" -lt 1024 ]; then
>> + echo " User data: $usersz bytes"
>> +elif [ "$usersz" -lt $((1024 * 1024)) ]; then
>> + echo " User data: $(( (usersz + 1023) / 1024 ))K
>> ($usersz)"
>> +elif [ "$usersz" -lt $((1024 * 1024 * 1024)) ]; then
>> + echo " User data: $(( (usersz + 1048575) / 1048576))M
>> ($usersz)"
>> +else
>> + echo " User data: $(( (usersz + 1073741823) /
>> 1073741824))G ($usersz)"
>> +fi
>> +dd if="$userimg" of="$outimg" conv=sparse bs=128K seek=$(( pos / (128 *
>> 1024) )) \
>> + count=$(( (usersz + 128 * 1024 - 1) / (128 * 1024) )) status=none
>> +pos=$((pos + usersz))
>> +truncate "$outimg" -s $pos
>> +
>> +echo ""
>> +echo "Instantiate via '-device
>> emmc,boot-partition-size=$bootsz,rpmb-partition-size=$rpmbsz,drive=$outimg'"
>
> That did not work for me. I had to provide a drive name, not the image path.
Yeah, I already fixed that in v3.
> An also create PCIe and SDHCI devices. That is:
>
> -device pcie-root-port,id=pcie-root,bus=pcie.0 \
> -device sdhci-pci,bus=pcie-root \
At least for the virt machine, just "-device sdhci-pci" is enough.
> -device
> emmc,boot-partition-size=$bootsz,rpmb-partition-size=$rpmbsz,drive=mmc0
> -drive if=none,id=mmc0,file=$outimg,format=raw"
>
> I applied the patches on top of QEMU 10.1.0 if that matters.
>
> Regards,
Thanks for review and testing!
Jan
--
Siemens AG, Foundational Technologies
Linux Expert Center
