Couple of lessons learned during USB driver testing:

- In kern_ndis.c:ndis_unload_driver(), test that ndis_block->nmb_rlist
  is not NULL before trying to free() it.

- In subr_pe.c:pe_get_import_descriptor(), do a case-insensitive
  match on the import module name. Most drivers I have encountered
  link against "ntoskrnl.exe" but the ASIX USB ethernet driver I'm
  testing with wants "NTOSKRNL.EXE."

- In subr_ntoskrnl.c:IoAllocateIrp(), return a pointer to the IRP
  instead of NULL. (Stub code leftover.)

- Also in subr_ntoskrnl.c, add ExAllocatePoolWithTag() and ExFreePool()
  to the function table list so they'll get exported to drivers properly.

sys/compat/ndis/kern_ndis.c

@@ -1682,7 +1682,8 @@ ndis_unload_driver(arg)
 
 	sc = arg;
 
-	free(sc->ndis_block->nmb_rlist, M_DEVBUF);
+	if (sc->ndis_block->nmb_rlist != NULL)
+		free(sc->ndis_block->nmb_rlist, M_DEVBUF);
 
 	ndis_flush_sysctls(sc);
 

sys/compat/ndis/subr_ntoskrnl.c

@@ -722,7 +722,7 @@ IoAllocateIrp(stsize, chargequota)
 
 	IoInitializeIrp(i, IoSizeOfIrp(stsize), stsize);
 
-	return (NULL);
+	return (i);
 }
 
 __stdcall static irp *
@@ -2615,6 +2615,8 @@ image_patch_table ntoskrnl_functbl[] = {
 	IMPORT_FUNC(InterlockedPushEntrySList),
 	IMPORT_FUNC(ExInterlockedPopEntrySList),
 	IMPORT_FUNC(ExInterlockedPushEntrySList),
+	IMPORT_FUNC(ExAllocatePoolWithTag),
+	IMPORT_FUNC(ExFreePool),
 	IMPORT_FUNC(KefAcquireSpinLockAtDpcLevel),
 	IMPORT_FUNC(KefReleaseSpinLockFromDpcLevel),
 	IMPORT_FUNC_MAP(KeAcquireSpinLockRaiseToDpc, KfAcquireSpinLock),

sys/compat/ndis/subr_pe.c

@@ -53,6 +53,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/errno.h>
 #ifdef _KERNEL
 #include <sys/systm.h>
+extern int ndis_strncasecmp(const char *, const char *, size_t);
+#define strncasecmp(a, b, c) ndis_strncasecmp(a, b, c)
 #else
 #include <stdio.h>
 #include <stdlib.h>
@@ -431,6 +433,8 @@ pe_relocate(imgbase)
  * may be linked against several modules, typically HAL.dll, ntoskrnl.exe
  * and NDIS.SYS. For each module, there is a list of imported function
  * names and their addresses.
+ *
+ * Note: module names are case insensitive!
  */
 
 int
@@ -455,7 +459,7 @@ pe_get_import_descriptor(imgbase, desc, module)
 	while (imp_desc->iid_nameaddr) {
 		modname = (char *)pe_translate_addr(imgbase,
 		    imp_desc->iid_nameaddr);
-		if (!strncmp(module, modname, strlen(module))) {
+		if (!strncasecmp(module, modname, strlen(module))) {
 			bcopy((char *)imp_desc, (char *)desc,
 			    sizeof(image_import_descriptor));
 			return(0);