add targets to Nmakefile to fetch boot images on windows, add a wscript program to fetch files over http without depending on curl/wget

Nmakefile

@@ -1,3 +1,7 @@
+!IF !DEFINED(BOOTIMAGE_VERSION)
+BOOTIMAGE_VERSION = latest
+!ENDIF
+
 !IF DEFINED(PLATFORM)
 
 LINK_FLAGS = /nologo shell32.lib
@@ -115,6 +119,12 @@ clean:
 	del factor.dll
 	del factor.dll.lib
 
-.PHONY: all default x86-32 x86-64 clean
+bootimage-x86-32:
+	cscript /nologo build-support\http-get.vbs http://factorcode.org/images/$(BOOTIMAGE_VERSION)/boot.winnt-x86.32.image boot.winnt-x86.32.image
+
+bootimage-x86-64:
+	cscript /nologo build-support\http-get.vbs http://factorcode.org/images/$(BOOTIMAGE_VERSION)/boot.winnt-x86.64.image boot.winnt.x86.64.image
+
+.PHONY: all bootimage-x86-32 bootimage-x86-64 default x86-32 x86-64 clean
 
 .SUFFIXES: .rs

build-support/http-get.vbs

@@ -0,0 +1,29 @@
+if WScript.Arguments.Count < 2 then
+    WScript.Echo "usage: http-get.vbs source-url dest-file"
+    WScript.Quit 1
+else
+    source_url = WScript.Arguments.Item(0)
+    dest_filename = WScript.Arguments.Item(1)
+
+    dim http, source_data
+    set http = CreateObject("WinHttp.WinHttpRequest.5.1")
+    http.Open "GET", source_url, false
+    http.Send
+
+    if http.Status = 200 then
+        dim dest_stream
+        set dest_stream = CreateObject("ADODB.Stream")
+
+        dest_stream.Type = 1 ' adTypeBinary
+        dest_stream.Open
+        dest_stream.Write http.ResponseBody
+        dest_stream.SaveToFile dest_filename, 2 ' adSaveCreateOverWrite
+
+        set dest_stream = nothing
+    else
+        WScript.Echo CStr(http.Status) + " " + http.StatusText + " when fetching " + source_url
+        WScript.Quit 1
+    end if
+
+    set http = nothing
+end if