PERFORCE change 135517 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=135517

Change 135517 by marcel at marcel_jnpr on 2008/02/16 21:41:02

	Save U-Boot's registers at startup and restore them when
	performing a syscall. This way we don't have to compile
	code specially to avoid using those registers. Otherwise
	we have to encode knowledge of those registers in at least
	4 makefiles and introduce a build knob to enable it all.
	This does not allow us to build everything with a single
	build world.

Affected files ...

.. //depot/projects/e500/lib/libstand/Makefile#7 edit
.. //depot/projects/e500/sys/boot/Makefile#4 edit
.. //depot/projects/e500/sys/boot/ficl/Makefile#5 edit
.. //depot/projects/e500/sys/boot/powerpc/Makefile#5 edit
.. //depot/projects/e500/sys/boot/powerpc/uboot/Makefile#5 edit
.. //depot/projects/e500/sys/boot/powerpc/uboot/start.S#3 edit
.. //depot/projects/e500/sys/boot/uboot/lib/Makefile#6 edit

Differences ...

==== //depot/projects/e500/lib/libstand/Makefile#7 (text+ko) ====

@@ -6,8 +6,6 @@
 #   quite large.
 #
 
-.include <bsd.own.mk>
-
 LIB=		stand
 NO_PROFILE=
 NO_PIC=
@@ -29,9 +27,6 @@
 .endif
 .if ${MACHINE_ARCH} == "powerpc"
 CFLAGS+=	-msoft-float -D_STANDALONE
-. if ${MK_UBOOT} != "no"
-CFLAGS+=	-ffixed-r14 -ffixed-r29
-. endif
 .endif
 .if ${MACHINE_ARCH} == "amd64"
 CFLAGS+=	-m32 -I.

==== //depot/projects/e500/sys/boot/Makefile#4 (text+ko) ====

@@ -13,18 +13,13 @@
 .endif
 
 # Build Open Firmware library.
-.if ${MACHINE_ARCH} == "sparc64"
+.if ${MACHINE_ARCH} == "powerpc" || ${MACHINE_ARCH} == "sparc64"
 SUBDIR+=		ofw
 .endif
 
+# Build U-Boot library.
 .if ${MACHINE_ARCH} == "powerpc"
-. if ${MK_UBOOT} != "no"
-# Build U-Boot library.
 SUBDIR+=		uboot
-. else
-# Build Open Firmware library.
-SUBDIR+=		ofw
-. endif
 .endif
 
 # Pick the machine-dependent subdir based on the target architecture.

==== //depot/projects/e500/sys/boot/ficl/Makefile#5 (text+ko) ====

@@ -1,8 +1,6 @@
 # $FreeBSD: src/sys/boot/ficl/Makefile,v 1.45 2007/10/15 14:20:24 nyan Exp $
 #
 
-.include <bsd.own.mk>
-
 .PATH: ${.CURDIR}/${MACHINE_ARCH:S/amd64/i386/}
 BASE_SRCS=	dict.c ficl.c fileaccess.c float.c loader.c math64.c \
 		prefix.c search.c stack.c tools.c vm.c words.c
@@ -19,15 +17,6 @@
 .endif
 .if ${MACHINE_ARCH} == "powerpc"
 CFLAGS+=	-msoft-float
-. if ${MK_UBOOT} != "no"
-#
-# Important notice: registers dedicated for U-Boot must NOT be used by the
-# loader code, as we are going to jump between loader(8) and U-Boot code back
-# and forth safely. For PowerPC these are r14 and r29, but always make
-# sure in the U-Boot cpu/{CPU}/config.mk, e.g. cpu/mpc85xx/config.mk
-#
-CFLAGS+=	-ffixed-r14 -ffixed-r29
-. endif
 .endif
 .if ${MACHINE} == "pc98"
 CFLAGS+=	-Os -DPC98

==== //depot/projects/e500/sys/boot/powerpc/Makefile#5 (text+ko) ====

@@ -1,11 +1,5 @@
 # $FreeBSD: src/sys/boot/powerpc/Makefile,v 1.2 2007/12/17 22:19:44 marcel Exp $
 
-.include <bsd.own.mk>
-
-.if ${MK_UBOOT} != "no"
-SUBDIR=		uboot
-.else
-SUBDIR=		ofw
-.endif
+SUBDIR=		ofw uboot
 
 .include <bsd.subdir.mk>

==== //depot/projects/e500/sys/boot/powerpc/uboot/Makefile#5 (text+ko) ====

@@ -61,13 +61,7 @@
 
 CLEANFILES+=	vers.c loader.help
 
-#
-# Important notice: registers dedicated for U-Boot must NOT be used by the
-# loader code, as we are going to jump between loader(8) and U-Boot code back
-# and forth safely. For PowerPC these are r14 and r29, but always make
-# sure in the U-Boot cpu/{CPU}/config.mk, e.g. cpu/mpc85xx/config.mk
-#
-CFLAGS+=	-ffreestanding -ffixed-r14 -ffixed-r29
+CFLAGS+=	-ffreestanding
 
 LDFLAGS=	-nostdlib -static -T ${.CURDIR}/ldscript.powerpc
 

==== //depot/projects/e500/sys/boot/powerpc/uboot/start.S#3 (text+ko) ====

@@ -38,17 +38,41 @@
 	lis	%r1, stack at ha
 	addi	%r1, %r1, stack at l
 	addi	%r1, %r1, (STACK_SIZE - 32)
+	/* Save U-Boot's r14 and r29 */
+	lis	%r11, saved_regs at ha
+	addi	%r11, %r11, saved_regs at l
+	stw	%r14, 0(%r11)
+	stw	%r29, 4(%r11)
 	b	main
 
 /*
  * syscall()
  */
 ENTRY(syscall)
+	stwu	%r1, -16(%r1)
+	mflr	%r0
+	stw	%r14, 8(%r1)
+	stw	%r29, 12(%r1)
+	stw	%r0, 20(%r1)
+	/* Restore U-Boot's r14 and r29 */
+	lis	%r11, saved_regs at ha
+	addi	%r11, %r11, saved_regs at l
+	lwz	%r14, 0(%r11)
+	lwz	%r29, 4(%r11)
+	/* Call into u-Boot */
 	lis	%r11, syscall_ptr at ha
 	addi	%r11, %r11, syscall_ptr at l
 	lwz	%r11, 0(%r11)
 	mtctr	%r11
-	bctr
+	bctrl
+	/* Epilogue */
+	lwz	%r11, 0(%r1)
+	lwz	%r0, 4(%r11)
+	mtlr	%r0
+	lwz	%r14, 8(%r1)
+	lwz	%r29, 12(%r1)
+	mr	%r1, %r11
+	blr
 
 /*
  * Data section
@@ -60,3 +84,7 @@
 
 GLOBAL(syscall_ptr)
 	.long	0
+GLOBAL(saved_regs)
+	.long	0	/* R14 */
+	.long	0	/* R29 */
+

==== //depot/projects/e500/sys/boot/uboot/lib/Makefile#6 (text+ko) ====

@@ -12,16 +12,6 @@
 
 CFLAGS+=	-ffreestanding
 
-.if ${MACHINE_ARCH} == "powerpc"
-#
-# Important notice: registers dedicated for U-Boot must NOT be used by the
-# loader code, as we are going to jump between loader(8) and U-Boot code back
-# and forth safely. For PowerPC these are r14 and r29, but always make
-# sure in the U-Boot cpu/{CPU}/config.mk, e.g. cpu/mpc85xx/config.mk
-#
-CFLAGS+=	-ffixed-r14 -ffixed-r29
-.endif
-
 .ifdef(BOOT_DISK_DEBUG)
 # Make the disk code more talkative
 CFLAGS+= -DDISK_DEBUG