X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=Documentation%2Fx86%2Fboot.txt;h=9efceff51bfb1327a52e54af308a3077ccf7a02d;hb=219c6734380e810adcf9d4c98c7ffed81ed44b4f;hp=7c3a8801b7ce0c20b3395022d937427405f138dd;hpb=219f358e0ba9a98640341e030533089860af1cc6;p=cascardo%2Flinux.git

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7c3a8801b7ce..9efceff51bfb 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -54,6 +54,9 @@ Protocol 2.10:	(Kernel 2.6.31) Added a protocol for relaxed alignment
 		beyond the kernel_alignment added, new init_size and
 		pref_address fields.  Added extended boot loader IDs.
 
+Protocol 2.11:	(Kernel 3.6) Added a field for offset of EFI handover
+		protocol entry point.
+
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or
@@ -189,6 +192,7 @@ Offset	Proto	Name		Meaning
 				of struct setup_data
 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
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -363,7 +367,8 @@ Protocol:	2.00+
   ext_loader_type <- 0x05
   ext_loader_ver  <- 0x23
 
-  Assigned boot loader ids:
+  Assigned boot loader ids (hexadecimal):
+
 	0  LILO			(0x00 reserved for pre-2.00 bootloader)
 	1  Loadlin
 	2  bootsect-loader	(0x20, all other values reserved)
@@ -378,6 +383,8 @@ Protocol:	2.00+
 	C  Arcturus Networks uCbootloader
 	E  Extended		(see ext_loader_type)
 	F  Special		(0xFF = undefined)
+       10  Reserved
+       11  Minimal Linux Bootloader <http://sebastian-plotz.blogspot.de>
 
   Please contact <hpa@zytor.com> if you need a bootloader ID
   value assigned.
@@ -690,6 +697,16 @@ Offset/size:	0x260/4
   else
 	runtime_start = pref_address
 
+Field name:	handover_offset
+Type:		read
+Offset/size:	0x264/4
+
+  This field is the offset from the beginning of the kernel image to
+  the EFI handover protocol entry point. Boot loaders using the EFI
+  handover protocol to boot the kernel should jump to this offset.
+
+  See EFI HANDOVER PROTOCOL below for more details.
+
 
 **** THE IMAGE CHECKSUM
 
@@ -1010,3 +1027,30 @@ segment; __BOOS_CS must have execute/read permission, and __BOOT_DS
 must have read/write permission; CS must be __BOOT_CS and DS, ES, SS
 must be __BOOT_DS; interrupt must be disabled; %esi must hold the base
 address of the struct boot_params; %ebp, %edi and %ebx must be zero.
+
+**** EFI HANDOVER PROTOCOL
+
+This protocol allows boot loaders to defer initialisation to the EFI
+boot stub. The boot loader is required to load the kernel/initrd(s)
+from the boot media and jump to the EFI handover protocol entry point
+which is hdr->handover_offset bytes from the beginning of
+startup_{32,64}.
+
+The function prototype for the handover entry point looks like this,
+
+    efi_main(void *handle, efi_system_table_t *table, struct boot_params *bp)
+
+'handle' is the EFI image handle passed to the boot loader by the EFI
+firmware, 'table' is the EFI system table - these are the first two
+arguments of the "handoff state" as described in section 2.3 of the
+UEFI specification. 'bp' is the boot loader-allocated boot params.
+
+The boot loader *must* fill out the following fields in bp,
+
+    o hdr.code32_start
+    o hdr.cmd_line_ptr
+    o hdr.cmdline_size
+    o hdr.ramdisk_image (if applicable)
+    o hdr.ramdisk_size  (if applicable)
+
+All other fields should be zero.