From: Michal Schmidt <mschmidt@redhat.com>
Subject: [PATCH RHEL-5] EFI: only warn on pre-1.00 version
Date: Thu, 26 Apr 2007 15:31:42 +0200
Bugzilla: 223282
Message-Id: <4630A9BE.4020705@redhat.com>
Changelog: [misc] EFI: only warn on pre-1.00 version


Currently the kernel prints out a warning if EFI system table major
revision is not exactly 1.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=223282

The patch is from Bjorn Helgaas <bjorn.helgaas@hp.com> and it's now in -mm.
The kernel builds OK with the patch on all architectures. I don't have a
machine with EFI 2.0, so I haven't tested it myself. There's not much
room for breakage here though.

Michal

diff -Nurp linux-2.6.18.i686.orig/arch/i386/kernel/efi.c linux-2.6.18.i686/arch/i386/kernel/efi.c
--- linux-2.6.18.i686.orig/arch/i386/kernel/efi.c	2007-04-26 12:52:37.000000000 +0200
+++ linux-2.6.18.i686/arch/i386/kernel/efi.c	2007-04-26 12:54:34.000000000 +0200
@@ -340,14 +340,12 @@ void __init efi_init(void)
 		printk(KERN_ERR PFX "Woah! Couldn't map the EFI system table.\n");
 	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 		printk(KERN_ERR PFX "Woah! EFI system table signature incorrect\n");
-	if ((efi.systab->hdr.revision ^ EFI_SYSTEM_TABLE_REVISION) >> 16 != 0)
-		printk(KERN_ERR PFX
-		       "Warning: EFI system table major version mismatch: "
-		       "got %d.%02d, expected %d.%02d\n",
+	if ((efi.systab->hdr.revision >> 16) == 0)
+		printk(KERN_ERR PFX "Warning: EFI system table version "
+		       "%d.%02d, expected 1.00 or greater\n",
 		       efi.systab->hdr.revision >> 16,
-		       efi.systab->hdr.revision & 0xffff,
-		       EFI_SYSTEM_TABLE_REVISION >> 16,
-		       EFI_SYSTEM_TABLE_REVISION & 0xffff);
+		       efi.systab->hdr.revision & 0xffff);
+
 	/*
 	 * Grab some details from the system table
 	 */
diff -Nurp linux-2.6.18.i686.orig/arch/ia64/hp/sim/boot/fw-emu.c linux-2.6.18.i686/arch/ia64/hp/sim/boot/fw-emu.c
--- linux-2.6.18.i686.orig/arch/ia64/hp/sim/boot/fw-emu.c	2006-09-20 05:42:06.000000000 +0200
+++ linux-2.6.18.i686/arch/ia64/hp/sim/boot/fw-emu.c	2007-04-26 12:54:34.000000000 +0200
@@ -287,7 +287,7 @@ sys_fw_init (const char *args, int argle
 
 	memset(efi_systab, 0, sizeof(efi_systab));
 	efi_systab->hdr.signature = EFI_SYSTEM_TABLE_SIGNATURE;
-	efi_systab->hdr.revision  = EFI_SYSTEM_TABLE_REVISION;
+	efi_systab->hdr.revision  = ((1 << 16) | 00);
 	efi_systab->hdr.headersize = sizeof(efi_systab->hdr);
 	efi_systab->fw_vendor = __pa("H\0e\0w\0l\0e\0t\0t\0-\0P\0a\0c\0k\0a\0r\0d\0\0");
 	efi_systab->fw_revision = 1;
diff -Nurp linux-2.6.18.i686.orig/arch/ia64/kernel/efi.c linux-2.6.18.i686/arch/ia64/kernel/efi.c
--- linux-2.6.18.i686.orig/arch/ia64/kernel/efi.c	2007-04-26 12:52:15.000000000 +0200
+++ linux-2.6.18.i686/arch/ia64/kernel/efi.c	2007-04-26 12:54:34.000000000 +0200
@@ -445,11 +445,11 @@ efi_init (void)
 		panic("Woah! Can't find EFI system table.\n");
 	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 		panic("Woah! EFI system table signature incorrect\n");
-	if ((efi.systab->hdr.revision ^ EFI_SYSTEM_TABLE_REVISION) >> 16 != 0)
-		printk(KERN_WARNING "Warning: EFI system table major version mismatch: "
-		       "got %d.%02d, expected %d.%02d\n",
-		       efi.systab->hdr.revision >> 16, efi.systab->hdr.revision & 0xffff,
-		       EFI_SYSTEM_TABLE_REVISION >> 16, EFI_SYSTEM_TABLE_REVISION & 0xffff);
+	if ((efi.systab->hdr.revision >> 16) == 0)
+		printk(KERN_WARNING "Warning: EFI system table version "
+		       "%d.%02d, expected 1.00 or greater\n",
+		       efi.systab->hdr.revision >> 16,
+		       efi.systab->hdr.revision & 0xffff);
 
 	config_tables = __va(efi.systab->tables);
 
diff -Nurp linux-2.6.18.i686.orig/include/linux/efi.h linux-2.6.18.i686/include/linux/efi.h
--- linux-2.6.18.i686.orig/include/linux/efi.h	2007-04-26 12:52:37.000000000 +0200
+++ linux-2.6.18.i686/include/linux/efi.h	2007-04-26 12:54:34.000000000 +0200
@@ -213,7 +213,6 @@ typedef struct {
 } efi_config_table_t;
 
 #define EFI_SYSTEM_TABLE_SIGNATURE ((u64)0x5453595320494249ULL)
-#define EFI_SYSTEM_TABLE_REVISION  ((1 << 16) | 00)
 
 typedef struct {
 	efi_table_hdr_t hdr;