powerpc/boot: Add support for 64bit little endian wrapper

The code is only slightly modified : entry points now use the FIXUP_ENDIAN trampoline to switch endian order. The 32bit wrapper is kept for big endian kernels and 64bit is enforced for little endian kernels with a PPC64_BOOT_WRAPPER config option. The linker script is generated using the kernel preprocessor flags to make use of the CONFIG_* definitions and the wrapper script is modified to take into account the new elf64ppc format. Finally, the zImage file is compiled as a position independent executable (-pie) which makes it loadable at any address by the firmware. Signed-off-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/boot: Add support for 64bit little endian wrapper
The code is only slightly modified : entry points now use the FIXUP_ENDIAN trampoline to switch endian order. The 32bit wrapper is kept for big endian kernels and 64bit is enforced for little endian kernels with a PPC64_BOOT_WRAPPER config option. The linker script is generated using the kernel preprocessor flags to make use of the CONFIG_* definitions and the wrapper script is modified to take into account the new elf64ppc format. Finally, the zImage file is compiled as a position independent executable (-pie) which makes it loadable at any address by the firmware. Signed-off-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cédric Le Goater · Benjamin Herrenschmidt · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent 2d9afb369b
Showing 7 changed files with 72 additions and 5 deletions Side-by-side Diff
arch/powerpc/boot/Makefile
arch/powerpc/boot/crt0.S
arch/powerpc/boot/ppc_asm.h
arch/powerpc/boot/pseries-head.S
arch/powerpc/boot/wrapper
arch/powerpc/boot/zImage.lds.S
arch/powerpc/platforms/Kconfig.cputype
@@ -22,8 +22,14 @@
 BOOTCFLAGS    := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 		 -fno-strict-aliasing -Os -msoft-float -pipe \
 		 -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
-		 -isystem $(shell $(CROSS32CC) -print-file-name=include) \
-		 -mbig-endian
+		 -isystem $(shell $(CROSS32CC) -print-file-name=include)
+ifdef CONFIG_PPC64_BOOT_WRAPPER
+BOOTCFLAGS	+= -m64
+endif
+ifdef CONFIG_CPU_BIG_ENDIAN
+BOOTCFLAGS	+= -mbig-endian
+endif
+
 BOOTAFLAGS	:= -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
  
 ifdef CONFIG_DEBUG_INFO
@@ -142,7 +148,11 @@
 $(obj)/empty.c:
 	@touch $@
  
-$(obj)/zImage.lds $(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds: $(obj)/%: $(srctree)/$(src)/%.S
+$(obj)/zImage.lds: $(obj)/%: $(srctree)/$(src)/%.S
+	$(CROSS32CC) $(cpp_flags) -E -Wp,-MD,$(depfile) -P -Upowerpc \
+		-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
+
+$(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds : $(obj)/%: $(srctree)/$(src)/%.S
 	@cp $< $@
  
 clean-files := $(zlib) $(zlibheader) $(zliblinuxheader) \
@@ -275,6 +275,7 @@
 	rfid
  
 1:	/* Return from OF */
+	FIXUP_ENDIAN
  
 	/* Restore registers and return. */
 	rldicl  r1,r1,0,32
@@ -62,5 +62,17 @@
 #define SPRN_TBRL	268
 #define SPRN_TBRU	269
  
+#define FIXUP_ENDIAN						   \
+	tdi   0, 0, 0x48; /* Reverse endian of b . + 8		*/ \
+	b     $+36;	  /* Skip trampoline if endian is good	*/ \
+	.long 0x05009f42; /* bcl 20,31,$+4			*/ \
+	.long 0xa602487d; /* mflr r10				*/ \
+	.long 0x1c004a39; /* addi r10,r10,28			*/ \
+	.long 0xa600607d; /* mfmsr r11				*/ \
+	.long 0x01006b69; /* xori r11,r11,1			*/ \
+	.long 0xa6035a7d; /* mtsrr0 r10				*/ \
+	.long 0xa6037b7d; /* mtsrr1 r11				*/ \
+	.long 0x2400004c  /* rfid				*/
+
 #endif /* _PPC64_PPC_ASM_H */
+#include "ppc_asm.h"
+
 	.text
  
 	.globl _zimage_start
 _zimage_start:
+	FIXUP_ENDIAN
 	b _zimage_start_lib
@@ -40,6 +40,7 @@
 binary=
 gzip=.gz
 pie=
+format=
  
 # cross-compilation prefix
 CROSS=
@@ -136,6 +137,14 @@
     kernel=vmlinux
 fi
  
+elfformat="`${CROSS}objdump -p "$kernel" | grep 'file format' | awk '{print $4}'`"
+case "$elfformat" in
+    elf64-powerpcle)	format=elf64lppc	;;
+    elf64-powerpc)	format=elf32ppc	;;
+    elf32-powerpc)	format=elf32ppc	;;
+esac
+
+
 platformo=$object/"$platform".o
 lds=$object/zImage.lds
 ext=strip
@@ -154,6 +163,10 @@
 pseries)
     platformo="$object/pseries-head.o $object/of.o $object/epapr.o"
     link_address='0x4000000'
+    if [ "$format" != "elf32ppc" ]; then
+	link_address=
+	pie=-pie
+    fi
     make_space=n
     ;;
 maple)
@@ -379,7 +392,7 @@
     if [ -n "$link_address" ] ; then
         text_start="-Ttext $link_address"
     fi
-    ${CROSS}ld -m elf32ppc -T $lds $text_start $pie -o "$ofile" \
+    ${CROSS}ld -m $format -T $lds $text_start $pie -o "$ofile" \
 	$platformo $tmp $object/wrapper.a
     rm $tmp
 fi
+#include <asm-generic/vmlinux.lds.h>
+
+#ifdef CONFIG_PPC64_BOOT_WRAPPER
+OUTPUT_ARCH(powerpc:common64)
+#else
 OUTPUT_ARCH(powerpc:common)
+#endif
 ENTRY(_zimage_start)
 EXTERN(_zimage_start)
 SECTIONS
  
@@ -16,7 +22,9 @@
     *(.rodata*)
     *(.data*)
     *(.sdata*)
+#ifndef CONFIG_PPC64_BOOT_WRAPPER
     *(.got2)
+#endif
   }
   .dynsym : { *(.dynsym) }
   .dynstr : { *(.dynstr) }
@@ -27,7 +35,13 @@
   }
   .hash : { *(.hash) }
   .interp : { *(.interp) }
-  .rela.dyn : { *(.rela*) }
+  .rela.dyn :
+  {
+#ifdef CONFIG_PPC64_BOOT_WRAPPER
+    __rela_dyn_start = .;
+#endif
+    *(.rela*)
+  }
  
   . = ALIGN(8);
   .kernel:dtb :
@@ -52,6 +66,15 @@
     *(.kernel:initrd)
     _initrd_end =  .;
   }
+
+#ifdef CONFIG_PPC64_BOOT_WRAPPER
+  .got :
+  {
+    __toc_start = .;
+    *(.got)
+    *(.toc)
+  }
+#endif
  
   . = ALIGN(4096);
   .bss       :
@@ -422,6 +422,7 @@
  
 config CPU_LITTLE_ENDIAN
 	bool "Build little endian kernel"
+	select PPC64_BOOT_WRAPPER
 	help
 	  Build a little endian kernel.
  
@@ -430,4 +431,8 @@
 	  little endian powerpc.
  
 endchoice
+
+config PPC64_BOOT_WRAPPER
+	def_bool n
+	depends on CPU_LITTLE_ENDIAN
...	...	@@ -22,8 +22,14 @@
22	22	BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
23	23	-fno-strict-aliasing -Os -msoft-float -pipe \
24	24	-fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
25		- -isystem $(shell $(CROSS32CC) -print-file-name=include) \
26		- -mbig-endian
	25	+ -isystem $(shell $(CROSS32CC) -print-file-name=include)
	26	+ifdef CONFIG_PPC64_BOOT_WRAPPER
	27	+BOOTCFLAGS += -m64
	28	+endif
	29	+ifdef CONFIG_CPU_BIG_ENDIAN
	30	+BOOTCFLAGS += -mbig-endian
	31	+endif
	32	+
27	33	BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
28	34
29	35	ifdef CONFIG_DEBUG_INFO
...	...	@@ -142,7 +148,11 @@
142	148	$(obj)/empty.c:
143	149	@touch $@
144	150
145		-$(obj)/zImage.lds $(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds: $(obj)/%: $(srctree)/$(src)/%.S
	151	+$(obj)/zImage.lds: $(obj)/%: $(srctree)/$(src)/%.S
	152	+ $(CROSS32CC) $(cpp_flags) -E -Wp,-MD,$(depfile) -P -Upowerpc \
	153	+ -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
	154	+
	155	+$(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds : $(obj)/%: $(srctree)/$(src)/%.S
146	156	@cp $< $@
147	157
148	158	clean-files := $(zlib) $(zlibheader) $(zliblinuxheader) \
...	...	@@ -275,6 +275,7 @@
275	275	rfid
276	276
277	277	1: /* Return from OF */
	278	+ FIXUP_ENDIAN
278	279
279	280	/* Restore registers and return. */
280	281	rldicl r1,r1,0,32
...	...	@@ -62,5 +62,17 @@
62	62	#define SPRN_TBRL 268
63	63	#define SPRN_TBRU 269
64	64
	65	+#define FIXUP_ENDIAN \
	66	+ tdi 0, 0, 0x48; /* Reverse endian of b . + 8 */ \
	67	+ b $+36; /* Skip trampoline if endian is good */ \
	68	+ .long 0x05009f42; /* bcl 20,31,$+4 */ \
	69	+ .long 0xa602487d; /* mflr r10 */ \
	70	+ .long 0x1c004a39; /* addi r10,r10,28 */ \
	71	+ .long 0xa600607d; /* mfmsr r11 */ \
	72	+ .long 0x01006b69; /* xori r11,r11,1 */ \
	73	+ .long 0xa6035a7d; /* mtsrr0 r10 */ \
	74	+ .long 0xa6037b7d; /* mtsrr1 r11 */ \
	75	+ .long 0x2400004c /* rfid */
	76	+
65	77	#endif /* _PPC64_PPC_ASM_H */
	1	+#include "ppc_asm.h"
	2	+
1	3	.text
2	4
3	5	.globl _zimage_start
4	6	_zimage_start:
	7	+ FIXUP_ENDIAN
5	8	b _zimage_start_lib
...	...	@@ -40,6 +40,7 @@
40	40	binary=
41	41	gzip=.gz
42	42	pie=
	43	+format=
43	44
44	45	# cross-compilation prefix
45	46	CROSS=
...	...	@@ -136,6 +137,14 @@
136	137	kernel=vmlinux
137	138	fi
138	139
	140	+elfformat="`${CROSS}objdump -p "$kernel" \| grep 'file format' \| awk '{print $4}'`"
	141	+case "$elfformat" in
	142	+ elf64-powerpcle) format=elf64lppc ;;
	143	+ elf64-powerpc) format=elf32ppc ;;
	144	+ elf32-powerpc) format=elf32ppc ;;
	145	+esac
	146	+
	147	+
139	148	platformo=$object/"$platform".o
140	149	lds=$object/zImage.lds
141	150	ext=strip
...	...	@@ -154,6 +163,10 @@
154	163	pseries)
155	164	platformo="$object/pseries-head.o $object/of.o $object/epapr.o"
156	165	link_address='0x4000000'
	166	+ if [ "$format" != "elf32ppc" ]; then
	167	+ link_address=
	168	+ pie=-pie
	169	+ fi
157	170	make_space=n
158	171	;;
159	172	maple)
...	...	@@ -379,7 +392,7 @@
379	392	if [ -n "$link_address" ] ; then
380	393	text_start="-Ttext $link_address"
381	394	fi
382		- ${CROSS}ld -m elf32ppc -T $lds $text_start $pie -o "$ofile" \
	395	+ ${CROSS}ld -m $format -T $lds $text_start $pie -o "$ofile" \
383	396	$platformo $tmp $object/wrapper.a
384	397	rm $tmp
385	398	fi
	1	+#include <asm-generic/vmlinux.lds.h>
	2	+
	3	+#ifdef CONFIG_PPC64_BOOT_WRAPPER
	4	+OUTPUT_ARCH(powerpc:common64)
	5	+#else
1	6	OUTPUT_ARCH(powerpc:common)
	7	+#endif
2	8	ENTRY(_zimage_start)
3	9	EXTERN(_zimage_start)
4	10	SECTIONS
5	11
...	...	@@ -16,7 +22,9 @@
16	22	(.rodata)
17	23	(.data)
18	24	(.sdata)
	25	+#ifndef CONFIG_PPC64_BOOT_WRAPPER
19	26	*(.got2)
	27	+#endif
20	28	}
21	29	.dynsym : { *(.dynsym) }
22	30	.dynstr : { *(.dynstr) }
...	...	@@ -27,7 +35,13 @@
27	35	}
28	36	.hash : { *(.hash) }
29	37	.interp : { *(.interp) }
30		- .rela.dyn : { (.rela) }
	38	+ .rela.dyn :
	39	+ {
	40	+#ifdef CONFIG_PPC64_BOOT_WRAPPER
	41	+ __rela_dyn_start = .;
	42	+#endif
	43	+ (.rela)
	44	+ }
31	45
32	46	. = ALIGN(8);
33	47	.kernel:dtb :
...	...	@@ -52,6 +66,15 @@
52	66	*(.kernel:initrd)
53	67	_initrd_end = .;
54	68	}
	69	+
	70	+#ifdef CONFIG_PPC64_BOOT_WRAPPER
	71	+ .got :
	72	+ {
	73	+ __toc_start = .;
	74	+ *(.got)
	75	+ *(.toc)
	76	+ }
	77	+#endif
55	78
56	79	. = ALIGN(4096);
57	80	.bss :
...	...	@@ -422,6 +422,7 @@
422	422
423	423	config CPU_LITTLE_ENDIAN
424	424	bool "Build little endian kernel"
	425	+ select PPC64_BOOT_WRAPPER
425	426	help
426	427	Build a little endian kernel.
427	428
...	...	@@ -430,4 +431,8 @@
430	431	little endian powerpc.
431	432
432	433	endchoice
	434	+
	435	+config PPC64_BOOT_WRAPPER
	436	+ def_bool n
	437	+ depends on CPU_LITTLE_ENDIAN