Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 176 insertions, 0 deletions

diff --git a/arch/i386/boot/edd.S b/arch/i386/boot/edd.S
new file mode 100644
index 00000000000..027d6b354ff
--- /dev/null
+++ b/arch/i386/boot/edd.S
@@ -0,0 +1,176 @@
+/*
+ * BIOS Enhanced Disk Drive support
+ * Copyright (C) 2002, 2003, 2004 Dell, Inc.
+ * by Matt Domsch <Matt_Domsch@dell.com> October 2002
+ * conformant to T13 Committee www.t13.org
+ *   projects 1572D, 1484D, 1386D, 1226DT
+ * disk signature read by Matt Domsch <Matt_Domsch@dell.com>
+ *	and Andrew Wilks <Andrew_Wilks@dell.com> September 2003, June 2004
+ * legacy CHS retreival by Patrick J. LoPresti <patl@users.sourceforge.net>
+ *      March 2004
+ * Command line option parsing, Matt Domsch, November 2004
+ */
+
+#include <linux/edd.h>
+#include <asm/setup.h>
+
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+	movb	$0, (EDD_MBR_SIG_NR_BUF)
+	movb	$0, (EDDNR)
+
+# Check the command line for two options:
+# edd=of  disables EDD completely  (edd=off)
+# edd=sk  skips the MBR test    (edd=skipmbr)
+	pushl	%esi
+    	cmpl	$0, %cs:cmd_line_ptr
+	jz	done_cl
+	movl	%cs:(cmd_line_ptr), %esi
+# ds:esi has the pointer to the command line now
+	movl	$(COMMAND_LINE_SIZE-7), %ecx
+# loop through kernel command line one byte at a time
+cl_loop:
+	cmpl	$EDD_CL_EQUALS, (%si)
+	jz	found_edd_equals
+	incl	%esi
+	loop	cl_loop
+	jmp	done_cl
+found_edd_equals:
+# only looking at first two characters after equals
+    	addl	$4, %esi
+	cmpw	$EDD_CL_OFF, (%si)	# edd=of
+	jz	do_edd_off
+	cmpw	$EDD_CL_SKIP, (%si)	# edd=sk
+	jz	do_edd_skipmbr
+	jmp	done_cl
+do_edd_skipmbr:
+    	popl	%esi
+	jmp	edd_start
+do_edd_off:
+	popl	%esi
+	jmp	edd_done
+done_cl:
+	popl	%esi
+
+
+# Read the first sector of each BIOS disk device and store the 4-byte signature
+edd_mbr_sig_start:
+	movb	$0x80, %dl			# from device 80
+	movw	$EDD_MBR_SIG_BUF, %bx		# store buffer ptr in bx
+edd_mbr_sig_read:
+	movl	$0xFFFFFFFF, %eax
+	movl	%eax, (%bx)			# assume failure
+	pushw	%bx
+	movb	$READ_SECTORS, %ah
+	movb	$1, %al				# read 1 sector
+	movb	$0, %dh				# at head 0
+	movw	$1, %cx				# cylinder 0, sector 0
+	pushw	%es
+	pushw	%ds
+	popw	%es
+    	movw	$EDDBUF, %bx			# disk's data goes into EDDBUF
+	pushw	%dx             # work around buggy BIOSes
+	stc                     # work around buggy BIOSes
+	int	$0x13
+	sti                     # work around buggy BIOSes
+	popw	%dx
+	popw	%es
+	popw	%bx
+	jc	edd_mbr_sig_done		# on failure, we're done.
+	movl	(EDDBUF+EDD_MBR_SIG_OFFSET), %eax # read sig out of the MBR
+	movl	%eax, (%bx)			# store success
+	incb	(EDD_MBR_SIG_NR_BUF)		# note that we stored something
+	incb	%dl				# increment to next device
+	addw	$4, %bx				# increment sig buffer ptr
+	cmpb	$EDD_MBR_SIG_MAX, (EDD_MBR_SIG_NR_BUF)	# Out of space?
+	jb	edd_mbr_sig_read		# keep looping
+edd_mbr_sig_done:
+
+# Do the BIOS Enhanced Disk Drive calls
+# This consists of two calls:
+#    int 13h ah=41h "Check Extensions Present"
+#    int 13h ah=48h "Get Device Parameters"
+#    int 13h ah=08h "Legacy Get Device Parameters"
+#
+# A buffer of size EDDMAXNR*(EDDEXTSIZE+EDDPARMSIZE) is reserved for our use
+# in the boot_params at EDDBUF.  The first four bytes of which are
+# used to store the device number, interface support map and version
+# results from fn41.  The next four bytes are used to store the legacy
+# cylinders, heads, and sectors from fn08. The following 74 bytes are used to
+# store the results from fn48.  Starting from device 80h, fn41, then fn48
+# are called and their results stored in EDDBUF+n*(EDDEXTSIZE+EDDPARMIZE).
+# Then the pointer is incremented to store the data for the next call.
+# This repeats until either a device doesn't exist, or until EDDMAXNR
+# devices have been stored.
+# The one tricky part is that ds:si always points EDDEXTSIZE bytes into
+# the structure, and the fn41 and fn08 results are stored at offsets
+# from there.  This removes the need to increment the pointer for
+# every store, and leaves it ready for the fn48 call.
+# A second one-byte buffer, EDDNR, in the boot_params stores
+# the number of BIOS devices which exist, up to EDDMAXNR.
+# In setup.c, copy_edd() stores both boot_params buffers away
+# for later use, as they would get overwritten otherwise.
+# This code is sensitive to the size of the structs in edd.h
+edd_start:
+						# %ds points to the bootsector
+       						# result buffer for fn48
+	movw	$EDDBUF+EDDEXTSIZE, %si		# in ds:si, fn41 results
+						# kept just before that
+	movb	$0x80, %dl			# BIOS device 0x80
+
+edd_check_ext:
+	movb	$CHECKEXTENSIONSPRESENT, %ah    # Function 41
+	movw	$EDDMAGIC1, %bx			# magic
+	int	$0x13				# make the call
+	jc	edd_done			# no more BIOS devices
+
+	cmpw	$EDDMAGIC2, %bx			# is magic right?
+	jne	edd_next			# nope, next...
+
+	movb	%dl, %ds:-8(%si)		# store device number
+	movb	%ah, %ds:-7(%si)		# store version
+	movw	%cx, %ds:-6(%si)		# store extensions
+	incb	(EDDNR)				# note that we stored something
+
+edd_get_device_params:
+	movw	$EDDPARMSIZE, %ds:(%si)		# put size
+	movw	$0x0, %ds:2(%si)		# work around buggy BIOSes
+	movb	$GETDEVICEPARAMETERS, %ah	# Function 48
+	int	$0x13				# make the call
+						# Don't check for fail return
+						# it doesn't matter.
+edd_get_legacy_chs:
+	xorw    %ax, %ax
+	movw    %ax, %ds:-4(%si)
+	movw    %ax, %ds:-2(%si)
+        # Ralf Brown's Interrupt List says to set ES:DI to
+	# 0000h:0000h "to guard against BIOS bugs"
+	pushw   %es
+	movw    %ax, %es
+	movw    %ax, %di
+	pushw   %dx                             # legacy call clobbers %dl
+	movb    $LEGACYGETDEVICEPARAMETERS, %ah # Function 08
+	int     $0x13                           # make the call
+	jc      edd_legacy_done                 # failed
+	movb    %cl, %al                        # Low 6 bits are max
+	andb    $0x3F, %al                      #   sector number
+	movb	%al, %ds:-1(%si)                # Record max sect
+	movb    %dh, %ds:-2(%si)                # Record max head number
+	movb    %ch, %al                        # Low 8 bits of max cyl
+	shr     $6, %cl
+	movb    %cl, %ah                        # High 2 bits of max cyl
+	movw    %ax, %ds:-4(%si)
+
+edd_legacy_done:
+	popw    %dx
+	popw    %es
+	movw	%si, %ax			# increment si
+	addw	$EDDPARMSIZE+EDDEXTSIZE, %ax
+	movw	%ax, %si
+
+edd_next:
+	incb	%dl				# increment to next device
+	cmpb	$EDDMAXNR, (EDDNR) 		# Out of space?
+	jb	edd_check_ext			# keep looping
+
+edd_done:
+#endif