From fcef0545be053ea69d6a4ea9bf60da477eecb51a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 18 Jan 2008 16:17:48 +0000
Subject: [PATCH] * A program for generating the hardware-specific bits of  
 configuration.nix.  Right now it finds out the following:

  - How many CPUs the machine has (for nix.maxJobs).
  - Whether to load KVM support (either kvm-intel or kvm-amd).
  - The modules necessary for the initrd by scanning the PCI and USB
    busses.  Only mass-storage and HID related modules are added.

svn path=/nixos/trunk/; revision=10221
---
 installer/nixos-hardware-scan.sh | 144 +++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 installer/nixos-hardware-scan.sh

diff --git a/installer/nixos-hardware-scan.sh b/installer/nixos-hardware-scan.sh
new file mode 100644
index 00000000000..06fbb11dfa1
--- /dev/null
+++ b/installer/nixos-hardware-scan.sh
@@ -0,0 +1,144 @@
+#! @shell@ -e
+
+
+kernelModules=
+initrdKernelModules=
+
+hasCPUFeature() {
+    local feature="$1"
+    cat /proc/cpuinfo | grep -q "^flags.* $feature\( \|$\)"
+}
+
+needKernelModule() {
+    kernelModules="$kernelModules \"$1\""
+}
+
+needInitrdKernelModule() {
+    initrdKernelModules="$initrdKernelModules \"$1\""
+}
+
+
+# Detect the number of CPU cores.
+cpus="$(cat /proc/cpuinfo | grep '^processor' | wc -l)"
+
+
+# CPU frequency scaling.  Not sure about this test.
+if hasCPUFeature "acpi"; then
+    needKernelModule "acpi-cpufreq"
+fi
+
+
+# Virtualization support?
+if hasCPUFeature "vmx"; then
+    needKernelModule "kvm-intel"
+fi
+
+if hasCPUFeature "svm"; then
+    needKernelModule "kvm-amd"
+fi
+
+
+# Look at the PCI devices and add necessary modules.  Note that most
+# modules are auto-detected so we don't need to list them here.
+# However, some are needed in the initrd to boot the system.
+
+pciCheck() {
+    local path="$1"
+    local vendor="$(cat $path/vendor)" 
+    local device="$(cat $path/device)"
+    local class="$(cat $path/class)"
+
+    local module
+    if test -e "$path/driver/module"; then
+        module=$(basename $(readlink -f $path/driver/module))
+    fi
+
+    echo "$path: $vendor $device $class $module"
+
+    if test -n "$module"; then
+        # See the bottom of http://pciids.sourceforge.net/pci.ids for
+        # device classes.
+        case $class in
+            0x01*)
+                # Mass-storage controller.  Definitely important.
+                needInitrdKernelModule $module
+                ;;
+            0x0c00*)
+                # Firewire controller.  A disk might be attached.
+                needInitrdKernelModule $module
+                ;;
+            0x0c03*)
+                # USB controller.  Needed if we want to use the
+                # keyboard when things go wrong in the initrd.
+                needInitrdKernelModule $module
+                ;;
+        esac
+    fi        
+}
+
+for path in /sys/bus/pci/devices/*; do
+    pciCheck "$path"
+done
+
+
+# Idem for USB devices.
+
+usbCheck() {
+    local path="$1"
+    local class="$(cat $path/bInterfaceClass)" 
+    local subclass="$(cat $path/bInterfaceSubClass)"
+    local protocol="$(cat $path/bInterfaceProtocol)"
+
+    local module
+    if test -e "$path/driver/module"; then
+        module=$(basename $(readlink -f $path/driver/module))
+    fi
+
+    echo "$path: $class $subclass $protocol $module"
+
+    if test -n "$module"; then
+        # See http://www.linux-usb.org/usb.ids for
+        # classes/subclasses/protocols.
+        case $class:$subclass:$protocol in
+            08:*)
+                # Mass-storage controller.  Definitely important.
+                needInitrdKernelModule $module
+                ;;
+            03:*:01)
+                # Keyboard.  Needed if we want to use the
+                # keyboard when things go wrong in the initrd.
+                needInitrdKernelModule $module
+                ;;
+        esac
+    fi        
+}
+
+for path in /sys/bus/usb/devices/*; do
+    if test -e "$path/bInterfaceClass"; then
+        usbCheck "$path"
+    fi
+done
+
+
+# Remove duplicate modules.  !!! preserve order
+kernelModules=$(for i in $kernelModules; do echo $i; done | sort | uniq)
+initrdKernelModules=$(for i in $initrdKernelModules; do echo $i; done | sort | uniq)
+
+
+# Generation the configuration file.
+cat <<EOF
+# This is a generated file.  Do not modify!
+# Make changes to /etc/nixos/configuration.nix instead.
+{
+  boot = {
+    initrd = {
+      extraKernelModules = [ $(echo $initrdKernelModules) ];
+    };
+    kernelModules = [ $(echo $kernelModules) ];
+  };
+
+  nix = {
+    maxJobs = $cpus;
+  };
+}
+EOF