Add support for probing the keyboard from pxeboot which will behave

exactly the same as passing -P to boot2.

Submitted by:	jhb

3 files changed, 44 insertions, 0 deletions

diff --git a/sys/boot/i386/pxeldr/Makefile b/sys/boot/i386/pxeldr/Makefile
index e299579..6f1b58e 100644
--- a/sys/boot/i386/pxeldr/Makefile
+++ b/sys/boot/i386/pxeldr/Makefile
@@ -10,7 +10,11 @@ PROG=		${BOOT}
 MAN8=		${BOOT}.8
 STRIP=
 BINDIR?=	/boot
+M4?=		m4
 
+.if defined(BOOT_PXELDR_PROBE_KEYBOARD)
+M4FLAGS+=	-DPROBE_KEYBOARD
+.endif
 
 .if exists(${.OBJDIR}/../loader)
 LOADER=	${.OBJDIR}/../loader/loader
@@ -32,6 +36,10 @@ ${LDR}: ${LDR}.o
 	objcopy -S -O binary ${LDR}.out ${.TARGET}
 .endif
 
+${LDR}.o: ${LDR}.s
+	(cd ${.CURDIR}; ${M4} ${M4FLAGS} ${LDR}.s) | \
+	   ${AS} ${AFLAGS} -o ${.TARGET}
+
 CLEANFILES+= ${LDR} ${LDR}.out ${LDR}.o ${BOOT}.tmp
 
 .include <bsd.prog.mk>
diff --git a/sys/boot/i386/pxeldr/pxeldr.S b/sys/boot/i386/pxeldr/pxeldr.S
index 510aff8..8558523 100644
--- a/sys/boot/i386/pxeldr/pxeldr.S
+++ b/sys/boot/i386/pxeldr/pxeldr.S
@@ -37,6 +37,7 @@
 		.set MEM_BTX_ENTRY,0x9010	# where BTX starts to execute
 		.set MEM_BTX_OFFSET,MEM_PAGE_SIZE # offset of BTX in the loader
 		.set MEM_BTX_CLIENT,0xa000	# where BTX clients live
+		.set MEM_BIOS_KEYBOARD,0x496	# BDA byte with keyboard bit
 #
 # a.out header fields
 #
@@ -52,6 +53,10 @@
 		.set KARGS_FLAGS_PXE,0x2	# flag to indicate booting from
 						#  PXE loader
 #
+# Boot howto bits
+#
+		.set RBX_SERIAL,0xc		# serial console
+#
 # Segment selectors.
 #
 		.set SEL_SDATA,0x8		# Supervisor data
@@ -63,6 +68,10 @@
 #
 		.set INT_SYS,0x30		# BTX syscall interrupt
 #
+# Bit in MEM_BIOS_KEYBOARD that is set if an enhanced keyboard is present
+#
+		.set KEYBOARD_BIT,0x10
+#
 # We expect to be loaded by the BIOS at 0x7c00 (standard boot loader entry
 # point)
 #
@@ -101,6 +110,15 @@ start:		cld				# string ops inc
 		orb $KARGS_FLAGS_PXE, 0x8(%bx)	# kargs->bootflags |=
 						#  KARGS_FLAGS_PXE
 		popl 0xc(%bx)			# kargs->pxeinfo = *PXENV+
+ifdef(`PROBE_KEYBOARD',`
+#
+# Look at the BIOS data area to see if we have an enhanced keyboard.  If not,
+# set the RBX_SERIAL bit in the howto byte.
+		testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD # keyboard present?
+		jnz keyb			# yes, so skip
+		orb $RBX_SERIAL, (%bx)		# enable serial console
+keyb:
+')
 #
 # Turn on the A20 address line
 #
diff --git a/sys/boot/i386/pxeldr/pxeldr.s b/sys/boot/i386/pxeldr/pxeldr.s
index 510aff8..8558523 100644
--- a/sys/boot/i386/pxeldr/pxeldr.s
+++ b/sys/boot/i386/pxeldr/pxeldr.s
@@ -37,6 +37,7 @@
 		.set MEM_BTX_ENTRY,0x9010	# where BTX starts to execute
 		.set MEM_BTX_OFFSET,MEM_PAGE_SIZE # offset of BTX in the loader
 		.set MEM_BTX_CLIENT,0xa000	# where BTX clients live
+		.set MEM_BIOS_KEYBOARD,0x496	# BDA byte with keyboard bit
 #
 # a.out header fields
 #
@@ -52,6 +53,10 @@
 		.set KARGS_FLAGS_PXE,0x2	# flag to indicate booting from
 						#  PXE loader
 #
+# Boot howto bits
+#
+		.set RBX_SERIAL,0xc		# serial console
+#
 # Segment selectors.
 #
 		.set SEL_SDATA,0x8		# Supervisor data
@@ -63,6 +68,10 @@
 #
 		.set INT_SYS,0x30		# BTX syscall interrupt
 #
+# Bit in MEM_BIOS_KEYBOARD that is set if an enhanced keyboard is present
+#
+		.set KEYBOARD_BIT,0x10
+#
 # We expect to be loaded by the BIOS at 0x7c00 (standard boot loader entry
 # point)
 #
@@ -101,6 +110,15 @@ start:		cld				# string ops inc
 		orb $KARGS_FLAGS_PXE, 0x8(%bx)	# kargs->bootflags |=
 						#  KARGS_FLAGS_PXE
 		popl 0xc(%bx)			# kargs->pxeinfo = *PXENV+
+ifdef(`PROBE_KEYBOARD',`
+#
+# Look at the BIOS data area to see if we have an enhanced keyboard.  If not,
+# set the RBX_SERIAL bit in the howto byte.
+		testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD # keyboard present?
+		jnz keyb			# yes, so skip
+		orb $RBX_SERIAL, (%bx)		# enable serial console
+keyb:
+')
 #
 # Turn on the A20 address line
 #