From 8a6a593eee41bc02c103e7f98047ea9b3c80c4a3 Mon Sep 17 00:00:00 2001
From: Aditya Ramani <a_ramani@apple.com>
Date: Wed, 4 Jun 2025 11:28:37 -0700
Subject: [PATCH] Selectively uncompress kernel binary from archive (#7)

---
 Sources/APIServer/Kernel/KernelService.swift | 16 +++++++++++++---
 Sources/CLI/System/SystemStart.swift         |  4 ++--
 Sources/ContainerClient/XPC+.swift           |  1 -
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/Sources/APIServer/Kernel/KernelService.swift b/Sources/APIServer/Kernel/KernelService.swift
index c85929b1..70b968e5 100644
--- a/Sources/APIServer/Kernel/KernelService.swift
+++ b/Sources/APIServer/Kernel/KernelService.swift
@@ -77,9 +77,8 @@ actor KernelService {
             .setDescription("Unpacking kernel")
         ])
         let archiveReader = try ArchiveReader(file: tarFile)
-        try archiveReader.extractContents(to: tempDir)
-        let kernelPath = tempDir.appendingPathComponent(kernelFilePath).resolvingSymlinksInPath()
-        try self.installKernel(kernelFile: kernelPath, platform: platform)
+        let kernelFile = try archiveReader.extractFile(from: kernelFilePath, to: tempDir)
+        try self.installKernel(kernelFile: kernelFile, platform: platform)
 
         if !FileManager.default.fileExists(atPath: tar.absoluteString) {
             try FileManager.default.removeItem(at: tarFile)
@@ -108,3 +107,14 @@ actor KernelService {
         return Kernel(path: defaultKernelPath, platform: platform)
     }
 }
+
+extension ArchiveReader {
+    fileprivate func extractFile(from: String, to directory: URL) throws -> URL {
+        let (_, data) = try self.extractFile(path: from)
+        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true, attributes: nil)
+        let fileName = URL(filePath: from).lastPathComponent
+        let fileURL = directory.appendingPathComponent(fileName)
+        try data.write(to: fileURL, options: .atomic)
+        return fileURL
+    }
+}
diff --git a/Sources/CLI/System/SystemStart.swift b/Sources/CLI/System/SystemStart.swift
index 757b81ca..f29cb951 100644
--- a/Sources/CLI/System/SystemStart.swift
+++ b/Sources/CLI/System/SystemStart.swift
@@ -85,13 +85,13 @@ extension Application {
                 )
             }
 
-            var kernelConfigured: Bool = false
+            var kernelConfigured: Bool = true
             var missingDependencies: [Dependencies] = []
             if await !initImageExists() {
                 missingDependencies.append(.initFs)
             }
             if await !kernelExists() {
-                kernelConfigured = true
+                kernelConfigured = false
                 missingDependencies.append(.kernel)
             }
             guard missingDependencies.count > 0 else {
diff --git a/Sources/ContainerClient/XPC+.swift b/Sources/ContainerClient/XPC+.swift
index 80fb95fa..aa06e4a7 100644
--- a/Sources/ContainerClient/XPC+.swift
+++ b/Sources/ContainerClient/XPC+.swift
@@ -94,7 +94,6 @@ public enum XPCKeys: String {
     case kernelTarURL
     case kernelFilePath
     case setDefault
-    case installedKernels
     case systemPlatform
     case kernelName
 }