From 790709a74056b1d2f12d3980adb251328273132a Mon Sep 17 00:00:00 2001
From: Mike Nordell <tamlin@algonet.se>
Date: Thu, 18 Oct 2007 08:00:59 +0000
Subject: [PATCH] Feeble attempt at getting NT4 vga.sys working by implementing
 HalFrameBufferCachingInformation case for HaliQuerySystemInformation.

svn path=/trunk/; revision=29656
---
 reactos/hal/halx86/generic/sysinfo.c | 53 ++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/reactos/hal/halx86/generic/sysinfo.c b/reactos/hal/halx86/generic/sysinfo.c
index ffdb34f210e..e81d6747107 100644
--- a/reactos/hal/halx86/generic/sysinfo.c
+++ b/reactos/hal/halx86/generic/sysinfo.c
@@ -23,13 +23,54 @@ PUCHAR _KdComPortInUse = 0;
 
 NTSTATUS
 NTAPI
-HaliQuerySystemInformation(IN HAL_QUERY_INFORMATION_CLASS InformationClass,
-                           IN ULONG BufferSize,
-                           IN OUT PVOID Buffer,
-                           OUT PULONG ReturnedLength)
+HaliQuerySystemInformation(IN     HAL_QUERY_INFORMATION_CLASS InformationClass,
+                           IN     ULONG  BufferSize,
+                           IN OUT PVOID  Buffer,
+                              OUT PULONG ReturnedLength)
 {
-    UNIMPLEMENTED;
-    return STATUS_NOT_IMPLEMENTED;
+#define REPORT_THIS_CASE(X) case X: DPRINT1("Unhandled case: %s\n", #X); break
+	switch (InformationClass)
+	{
+		REPORT_THIS_CASE(HalInstalledBusInformation);
+		REPORT_THIS_CASE(HalProfileSourceInformation);
+		REPORT_THIS_CASE(HalInformationClassUnused1);
+		REPORT_THIS_CASE(HalPowerInformation);
+		REPORT_THIS_CASE(HalProcessorSpeedInformation);
+		REPORT_THIS_CASE(HalCallbackInformation);
+		REPORT_THIS_CASE(HalMapRegisterInformation);
+		REPORT_THIS_CASE(HalMcaLogInformation);
+		case HalFrameBufferCachingInformation:
+		if (BufferSize >= 1)
+		{
+			// The only caller that has been seen calling this function told
+			// us it expected a single byte back. We therefore guess it expects
+			// a BOOLEAN, and we dream up the value TRUE to (we think) tell it
+			// "Sure, the framebuffer is cached".
+			DPRINT("%s: caller expects %u bytes (should be 1)\n", "HalFrameBufferCachingInformation", BufferSize);
+			BOOLEAN ToReturn = TRUE;
+			ASSERT(sizeof(BOOLEAN) == 1);
+			*ReturnedLength = sizeof(BOOLEAN);
+			RtlCopyMemory(Buffer, &ToReturn, sizeof(BOOLEAN));
+			return STATUS_SUCCESS;
+		}
+		break;
+		REPORT_THIS_CASE(HalDisplayBiosInformation);
+		REPORT_THIS_CASE(HalProcessorFeatureInformation);
+		REPORT_THIS_CASE(HalNumaTopologyInterface);
+		REPORT_THIS_CASE(HalErrorInformation);
+		REPORT_THIS_CASE(HalCmcLogInformation);
+		REPORT_THIS_CASE(HalCpeLogInformation);
+		REPORT_THIS_CASE(HalQueryMcaInterface);
+		REPORT_THIS_CASE(HalQueryAMLIIllegalIOPortAddresses);
+		REPORT_THIS_CASE(HalQueryMaxHotPlugMemoryAddress);
+		REPORT_THIS_CASE(HalPartitionIpiInterface);
+		REPORT_THIS_CASE(HalPlatformInformation);
+		REPORT_THIS_CASE(HalQueryProfileSourceList);
+	}
+#undef REPORT_THIS_CASE
+
+	UNIMPLEMENTED;
+	return STATUS_NOT_IMPLEMENTED;
 }
 
 NTSTATUS