DellEMC: Z9332f - Graceful platform reboot (sonic-net#10240)

Why I did it
To gracefully unmount filesystems and stop containers while performing a cold reboot.
Unmount ONIE-BOOT if mounted during fast/soft/warm reboot
How I did it
Override systemd-reboot service to perform a cold reboot.
Unmount ONIE-BOOT if mounted using fast/soft/warm-reboot plugins.
How to verify it
On reboot, verify that the container stop and filesystem unmount services have completed execution before the platform reboot.

platform/broadcom/sonic-platform-modules-dell/debian/platform-modules-z9332f.install

@@ -4,7 +4,11 @@ z9332f/scripts/sensors usr/bin
 z9332f/cfg/z9332f-modules.conf etc/modules-load.d
 z9332f/systemd/platform-modules-z9332f.service etc/systemd/system
 z9332f/modules/sonic_platform-1.0-py3-none-any.whl usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
-common/platform_reboot usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
+z9332f/scripts/platform_reboot_override usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
+z9332f/scripts/override.conf /etc/systemd/system/systemd-reboot.service.d
+z9332f/scripts/fast-reboot_plugin usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
+z9332f/scripts/soft-reboot_plugin usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
+z9332f/scripts/warm-reboot_plugin usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0
 common/pcisysfs.py usr/bin
 common/io_rd_wr.py usr/local/bin
 common/fw-updater usr/local/bin

platform/broadcom/sonic-platform-modules-dell/z9332f/scripts/fast-reboot_plugin

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+ONIE_PATH="/mnt/onie-boot"
+
+# Unmount ONIE partition if mounted
+if grep -qs ${ONIE_PATH} /proc/mounts; then
+    umount ${ONIE_PATH}
+fi

platform/broadcom/sonic-platform-modules-dell/z9332f/scripts/override.conf

@@ -0,0 +1,3 @@
+[Service]
+ExecStart=
+ExecStart=/usr/share/sonic/device/x86_64-dellemc_z9332f_d1508-r0/platform_reboot_override

platform/broadcom/sonic-platform-modules-dell/z9332f/scripts/platform_reboot_override

@@ -0,0 +1,23 @@
+#!/usr/bin/python3
+import os
+import struct
+
+PORT_RES = '/dev/port'
+
+
+def portio_reg_write(resource, offset, val):
+    fd = os.open(resource, os.O_RDWR)
+    if(fd < 0):
+        print('file open failed %s' % resource)
+        return
+    if(os.lseek(fd, offset, os.SEEK_SET) != offset):
+        print('lseek failed on %s' % resource)
+        return
+    ret = os.write(fd, struct.pack('B', val))
+    if(ret != 1):
+        print('write failed %d' % ret)
+        return
+    os.close(fd)
+
+if __name__ == "__main__":
+    portio_reg_write(PORT_RES, 0xcf9, 0xe)

platform/broadcom/sonic-platform-modules-dell/z9332f/scripts/soft-reboot_plugin

@@ -0,0 +1 @@
+fast-reboot_plugin

platform/broadcom/sonic-platform-modules-dell/z9332f/scripts/warm-reboot_plugin

@@ -0,0 +1 @@
+fast-reboot_plugin