Merge branch 'x86-grub2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 grub2 updates from Ingo Molnar:
 "This extends the x86 boot protocol to include an address for the RSDP
  table - utilized by Xen currently.

  Matching Grub2 patches are pending as well. (Juergen Gross)"

* 'x86-grub2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/acpi, x86/boot: Take RSDP address for boot params if available
  x86/boot: Add ACPI RSDP address to setup_header
  x86/xen: Fix boot loader version reported for PVH guests

1 files changed, 31 insertions, 1 deletions

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 5e9b826b5f62..7727db8f94bc 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -61,6 +61,18 @@ Protocol 2.12:	(Kernel 3.8) Added the xloadflags field and extension fields
 	 	to struct boot_params for loading bzImage and ramdisk
 		above 4G in 64bit.
 
+Protocol 2.13:	(Kernel 3.14) Support 32- and 64-bit flags being set in
+		xloadflags to support booting a 64-bit kernel from 32-bit
+		EFI
+
+Protocol 2.14:	(Kernel 4.20) Added acpi_rsdp_addr holding the physical
+		address of the ACPI RSDP table.
+		The bootloader updates version with:
+		0x8000 | min(kernel-version, bootloader-version)
+		kernel-version being the protocol version supported by
+		the kernel and bootloader-version the protocol version
+		supported by the bootloader.
+
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or
@@ -197,6 +209,7 @@ Offset	Proto	Name		Meaning
 0258/8	2.10+	pref_address	Preferred loading address
 0260/4	2.10+	init_size	Linear memory required during initialization
 0264/4	2.11+	handover_offset	Offset of handover entry point
+0268/8	2.14+	acpi_rsdp_addr	Physical address of RSDP table
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -309,7 +322,7 @@ Protocol:	2.00+
   Contains the magic number "HdrS" (0x53726448).
 
 Field name:	version
-Type:		read
+Type:		modify
 Offset/size:	0x206/2
 Protocol:	2.00+
 
@@ -317,6 +330,12 @@ Protocol:	2.00+
   e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
   10.17.
 
+  Up to protocol version 2.13 this information is only read by the
+  bootloader. From protocol version 2.14 onwards the bootloader will
+  write the used protocol version or-ed with 0x8000 to the field. The
+  used protocol version will be the minimum of the supported protocol
+  versions of the bootloader and the kernel.
+
 Field name:	realmode_swtch
 Type:		modify (optional)
 Offset/size:	0x208/4
@@ -744,6 +763,17 @@ Offset/size:	0x264/4
 
   See EFI HANDOVER PROTOCOL below for more details.
 
+Field name:	acpi_rsdp_addr
+Type:		write
+Offset/size:	0x268/8
+Protocol:	2.14+
+
+  This field can be set by the boot loader to tell the kernel the
+  physical address of the ACPI RSDP table.
+
+  A value of 0 indicates the kernel should fall back to the standard
+  methods to locate the RSDP.
+
 
 **** THE IMAGE CHECKSUM