From b19b980b2e4a4f94a2fa65d3677fb85f86cd65fa Mon Sep 17 00:00:00 2001
From: Frank Rojas <45807133+frankroj@users.noreply.github.com>
Date: Fri, 14 Jul 2023 18:02:18 -0400
Subject: [PATCH] Update Boot Image with CU Article 2

---
 windows/deployment/update-boot-image.md | 83 ++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/windows/deployment/update-boot-image.md b/windows/deployment/update-boot-image.md
index 1e1246c0a1..4c8b669cc4 100644
--- a/windows/deployment/update-boot-image.md
+++ b/windows/deployment/update-boot-image.md
@@ -20,8 +20,89 @@ appliesto:
 
 # Update Windows PE boot image with the latest cumulative update
 
+<!-- 7894697 -->
+
 This walkthrough describes how to update a Windows PE (WinPE) boot image with the latest cumulative update.
 
 ## Prerequisites
 
-- [Windows Assessment and Deployment Kit (ADK)](https://docs.microsoft.com/windows-hardware/get-started/adk-install). Recommended to use the latest version of the ADK.
\ No newline at end of file
+- [Windows Assessment and Deployment Kit (ADK)](/windows-hardware/get-started/adk-install). Recommended to use the latest version of the ADK.
+
+## Overview
+
+Note about boot.wim from installation media
+
+## Steps
+
+1. Download and install ADK
+2. Download cumulative update (CU)
+3. Backup existing boot image (e.g. winpe.wim or boot.wim)
+4. Mount boot image to temporary mount folder
+5. Add optional components to boot image
+6. Add cumulative update (CU) to boot image
+7. Copy boot files from mounted image to ADK installation location
+8. Perform component cleanup
+9. Unmount boot image and save changes
+10. Export boot image to reduce size
+
+## Step 1: Download and install ADK
+
+## Step 2: Download CU
+
+## Step 3: Backup existing boot image
+
+## Step 4: Mount boot image to temporary mount folder
+
+## Step 5: Add optional components to boot image
+
+## Step 6: Add cumulative update (CU) to boot image
+
+## Step 7: Copy boot files from mounted image to ADK installation location
+
+## Step 8: Perform component cleanup
+
+## Step 9: Unmount boot image and save changes
+
+## Step 10: Export boot image to reduce size
+
+## Script outline
+
+This PowerShell script appears to be a patching script for the Windows Assessment and Deployment Kit (ADK) and the Windows Preinstallation Environment (WinPE). Here's a breakdown of what the script does:
+
+1. It begins with some comments explaining the purpose of the script and providing links to relevant documentation.
+
+2. The script defines various variables such as `$SMSProvider2012R2`, `$MountFolder`, `$downloads`, and several `$CUDownloadUrl` variables. These variables specify download URLs for cumulative updates (CUs) and other files.
+
+3. The script includes functions like `Test-RegistryValue` and `Get-RegistryValue` for checking and retrieving registry values.
+
+4. It checks if the ADK is installed on the system by checking the registry key `HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows Kits\Installed Roots`. If the ADK is detected, it retrieves the installation location from the registry.
+
+5. The script verifies the existence of the WinPE image file (`winpe.wim`) and extracts the version information from it.
+
+6. Depending on the WinPE version, the script selects the appropriate CU download URL and sets the `$SSURequired` flag if a Servicing Stack Update (SSU) is needed.
+
+7. It checks if certain folders exist and creates them if necessary (`$downloads`, `$downloads\SSU`, and `$MountFolder`).
+
+8. If the CU file does not already exist in the specified download folder, it uses `Start-BitsTransfer` to download it from the provided URL.
+
+9. If an SSU is required, it performs a similar download process for the SSU file.
+
+10. The script creates a backup of the existing `winpe.wim` file by copying it to `winpe.bak`. If a previous backup already exists, it renames it with the current date appended.
+
+11. It mounts the `winpe.wim` file using `Mount-WindowsImage` to a temporary mount folder (`$MountFolder`).
+
+12. If an SSU is required, it adds the SSU package to the mounted image using `Add-WindowsPackage`.
+
+13. It then iterates through a list of optional components (`$OptionalComponents`) and adds the corresponding packages to the mounted image using `Add-WindowsPackage`. It also checks for language-specific versions of the components and adds them if available.
+
+14. The script adds the downloaded CU package to the mounted image using `Add-WindowsPackage`.
+
+15. It copies updated boot manager files (`bootmgr.efi` and `bootmgfw.efi`) from the mounted image back to the ADK installation location.
+
+16. It performs a component cleanup operation on the mounted image using `dism.exe` to reduce the image size.
+
+17. The script exports the list of installed packages in the modified image to a text file.
+
+18. Finally, it dismounts the image with the modifications, saves the changes, and exports the modified `winpe.wim` file as a new file with reduced file size. It also creates a backup of the original `winpe.wim` file and cleans up temporary files.
+
+The script appears to be designed to update and patch the WinPE image in the ADK installation based on the installed ADK version and the provided CU and SSU files.