Add pensando platform (sonic-net#15978)

This commit adds support for pensando asic called ELBA. ELBA is used in pci based cards and in smartswitches.

#### Why I did it
This commit introduces pensando platform which is based on ELBA ASIC.
##### Work item tracking
- Microsoft ADO **(number only)**:

#### How I did it
Created platform/pensando folder and created makefiles specific to pensando.
This mainly creates pensando docker (which OEM's need to download before building an image) which has all the userspace to initialize and use the DPU (ELBA ASIC).
Output of the build process creates two images which can be used from ONIE and goldfw.
Recommendation is use to use ONIE.
#### How to verify it
Load the SONiC image via ONIE or goldfw and make sure the interfaces are UP.

##### Description for the changelog
Add pensando platform support.

Author: ashwin-h

.gitignore

@@ -41,6 +41,9 @@ installer/x86_64/platforms/
 # Misc. files
 asic_config_checksum
 files/Aboot/boot0
+files/dsc/MANIFEST
+files/dsc/install_debian
+files/dsc/fs.zip
 files/initramfs-tools/arista-convertfs
 files/initramfs-tools/union-mount
 

build_debian.sh

@@ -50,8 +50,8 @@ TRUSTED_GPG_DIR=$BUILD_TOOL_PATH/trusted.gpg.d
     echo "Error: Invalid ONIE_IMAGE_PART_SIZE in onie image config file"
     exit 1
 }
-[ -n "$ONIE_INSTALLER_PAYLOAD" ] || {
-    echo "Error: Invalid ONIE_INSTALLER_PAYLOAD in onie image config file"
+[ -n "$INSTALLER_PAYLOAD" ] || {
+    echo "Error: Invalid INSTALLER_PAYLOAD in onie image config file"
     exit 1
 }
 [ -n "$FILESYSTEM_SQUASHFS" ] || {
@@ -753,14 +753,27 @@ sudo chroot $FILESYSTEM_ROOT update-initramfs -u
 ## Convert initrd image to u-boot format
 if [[ $TARGET_BOOTLOADER == uboot ]]; then
     INITRD_FILE=initrd.img-${LINUX_KERNEL_VERSION}-${CONFIGURED_ARCH}
+    KERNEL_FILE=vmlinuz-${LINUX_KERNEL_VERSION}-${CONFIGURED_ARCH}
     if [[ $CONFIGURED_ARCH == armhf ]]; then
         INITRD_FILE=initrd.img-${LINUX_KERNEL_VERSION}-armmp
         sudo LANG=C chroot $FILESYSTEM_ROOT mkimage -A arm -O linux -T ramdisk -C gzip -d /boot/$INITRD_FILE /boot/u${INITRD_FILE}
         ## Overwriting the initrd image with uInitrd
         sudo LANG=C chroot $FILESYSTEM_ROOT mv /boot/u${INITRD_FILE} /boot/$INITRD_FILE
     elif [[ $CONFIGURED_ARCH == arm64 ]]; then
-        sudo cp -v $PLATFORM_DIR/${sonic_asic_platform}-${CONFIGURED_ARCH}/sonic_fit.its $FILESYSTEM_ROOT/boot/
-        sudo LANG=C chroot $FILESYSTEM_ROOT mkimage -f /boot/sonic_fit.its /boot/sonic_${CONFIGURED_ARCH}.fit
+        if [[ $CONFIGURED_PLATFORM == pensando ]]; then
+            ## copy device tree file into boot (XXX: need to compile dtb from dts)
+            sudo cp -v $PLATFORM_DIR/pensando/elba-asic-psci.dtb $FILESYSTEM_ROOT/boot/
+            ## make kernel as gzip file
+            sudo LANG=C chroot $FILESYSTEM_ROOT gzip /boot/${KERNEL_FILE}
+            sudo LANG=C chroot $FILESYSTEM_ROOT mv /boot/${KERNEL_FILE}.gz /boot/${KERNEL_FILE}
+            ## Convert initrd image to u-boot format
+            sudo LANG=C chroot $FILESYSTEM_ROOT mkimage -A arm64 -O linux -T ramdisk -C gzip -d /boot/$INITRD_FILE /boot/u${INITRD_FILE}
+            ## Overwriting the initrd image with uInitrd
+            sudo LANG=C chroot $FILESYSTEM_ROOT mv /boot/u${INITRD_FILE} /boot/$INITRD_FILE
+        else
+            sudo cp -v $PLATFORM_DIR/${sonic_asic_platform}-${CONFIGURED_ARCH}/sonic_fit.its $FILESYSTEM_ROOT/boot/
+            sudo LANG=C chroot $FILESYSTEM_ROOT mkimage -f /boot/sonic_fit.its /boot/sonic_${CONFIGURED_ARCH}.fit
+        fi
     fi
 fi
 
@@ -811,7 +824,7 @@ if [[ "$CHANGE_DEFAULT_PASSWORD" == "y" ]]; then
 fi
 
 ## Compress most file system into squashfs file
-sudo rm -f $ONIE_INSTALLER_PAYLOAD $FILESYSTEM_SQUASHFS
+sudo rm -f $INSTALLER_PAYLOAD $FILESYSTEM_SQUASHFS
 ## Output the file system total size for diag purpose
 ## Note: -x to skip directories on different file systems, such as /proc
 sudo du -hsx $FILESYSTEM_ROOT
@@ -856,5 +869,5 @@ fi
 pushd $FILESYSTEM_ROOT && sudo tar -I $GZ_COMPRESS_PROGRAM -cf $OLDPWD/$FILESYSTEM_DOCKERFS -C ${DOCKERFS_PATH}var/lib/docker .; popd
 
 ## Compress together with /boot, /var/lib/docker and $PLATFORM_DIR as an installer payload zip file
-pushd $FILESYSTEM_ROOT && sudo tar -I $GZ_COMPRESS_PROGRAM -cf platform.tar.gz -C $PLATFORM_DIR . && sudo zip -n .gz $OLDPWD/$ONIE_INSTALLER_PAYLOAD -r boot/ platform.tar.gz; popd
-sudo zip -g -n .squashfs:.gz $ONIE_INSTALLER_PAYLOAD $FILESYSTEM_SQUASHFS $FILESYSTEM_DOCKERFS
+pushd $FILESYSTEM_ROOT && sudo tar -I $GZ_COMPRESS_PROGRAM -cf platform.tar.gz -C $PLATFORM_DIR . && sudo zip -n .gz $OLDPWD/$INSTALLER_PAYLOAD -r boot/ platform.tar.gz; popd
+sudo zip -g -n .squashfs:.gz $INSTALLER_PAYLOAD $FILESYSTEM_SQUASHFS $FILESYSTEM_DOCKERFS