SliTaz Repositories

1 From: Lasse Collin <lasse.collin@tukaani.org>

2 Date: Thu, 2 Dec 2010 19:14:57 +0000 (+0200)

3 Subject: x86: Support XZ-compressed kernel

4 X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fpkl%2Fsquashfs-xz.git;a=commitdiff_plain;h=d4ad78414e5312126127b1f88cdaf8584af3eef1

5

6 x86: Support XZ-compressed kernel

7

8 This integrates the XZ decompression code to the x86

9 pre-boot code.

10

11 mkpiggy.c is updated to reserve about 32 KiB more buffer safety

12 margin for kernel decompression. It is done unconditionally for

13 all decompressors to keep the code simpler.

14

15 The XZ decompressor needs around 30 KiB of heap, so the heap size

16 is increased to 32 KiB on both x86-32 and x86-64.

17

18 Documentation/x86/boot.txt is updated to list the XZ magic number.

19

20 With the x86 BCJ filter in XZ, XZ-compressed x86 kernel tends to be

21 a few percent smaller than the equivalent LZMA-compressed kernel.

22

23 Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>

24 ---

25

26 diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt

27 index 30b43e1..3988cde 100644

28 --- a/Documentation/x86/boot.txt

29 +++ b/Documentation/x86/boot.txt

30 @@ -621,9 +621,9 @@ Protocol: 2.08+

31 The payload may be compressed. The format of both the compressed and

32 uncompressed data should be determined using the standard magic

33 numbers. The currently supported compression formats are gzip

34 - (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A) and LZMA

35 - (magic number 5D 00). The uncompressed payload is currently always ELF

36 - (magic number 7F 45 4C 46).

37 + (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA

38 + (magic number 5D 00), and XZ (magic number FD 37). The uncompressed

39 + payload is currently always ELF (magic number 7F 45 4C 46).

40

41 Field name: payload_length

42 Type: read

43 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig

44 index cea0cd9..f3db0d7 100644

45 --- a/arch/x86/Kconfig

46 +++ b/arch/x86/Kconfig

47 @@ -51,6 +51,7 @@ config X86

48 select HAVE_KERNEL_GZIP

49 select HAVE_KERNEL_BZIP2

50 select HAVE_KERNEL_LZMA

51 + select HAVE_KERNEL_XZ

52 select HAVE_KERNEL_LZO

53 select HAVE_HW_BREAKPOINT

54 select HAVE_MIXED_BREAKPOINTS_REGS

55 diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile

56 index 0c22955..09664ef 100644

57 --- a/arch/x86/boot/compressed/Makefile

58 +++ b/arch/x86/boot/compressed/Makefile

59 @@ -4,7 +4,7 @@

60 # create a compressed vmlinux image from the original vmlinux

61 #

62

63 -targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.lzo head_$(BITS).o misc.o string.o cmdline.o early_serial_console.o piggy.o

64 +targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo head_$(BITS).o misc.o string.o cmdline.o early_serial_console.o piggy.o

65

66 KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2

67 KBUILD_CFLAGS += -fno-strict-aliasing -fPIC

68 @@ -49,12 +49,15 @@ $(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE

69 $(call if_changed,bzip2)

70 $(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE

71 $(call if_changed,lzma)

72 +$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE

73 + $(call if_changed,xzkern)

74 $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE

75 $(call if_changed,lzo)

76

77 suffix-$(CONFIG_KERNEL_GZIP) := gz

78 suffix-$(CONFIG_KERNEL_BZIP2) := bz2

79 suffix-$(CONFIG_KERNEL_LZMA) := lzma

80 +suffix-$(CONFIG_KERNEL_XZ) := xz

81 suffix-$(CONFIG_KERNEL_LZO) := lzo

82

83 quiet_cmd_mkpiggy = MKPIGGY $@

84 diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c

85 index 8f7bef8..6d4cab7 100644

86 --- a/arch/x86/boot/compressed/misc.c

87 +++ b/arch/x86/boot/compressed/misc.c

88 @@ -139,6 +139,10 @@ static int lines, cols;

89 #include "../../../../lib/decompress_unlzma.c"

90 #endif

91

92 +#ifdef CONFIG_KERNEL_XZ

93 +#include "../../../../lib/decompress_unxz.c"

94 +#endif

95 +

96 #ifdef CONFIG_KERNEL_LZO

97 #include "../../../../lib/decompress_unlzo.c"

98 #endif

99 diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c

100 index 5c22812..646aa78 100644

101 --- a/arch/x86/boot/compressed/mkpiggy.c

102 +++ b/arch/x86/boot/compressed/mkpiggy.c

103 @@ -74,7 +74,7 @@ int main(int argc, char *argv[])

104

105 offs = (olen > ilen) ? olen - ilen : 0;

106 offs += olen >> 12; /* Add 8 bytes for each 32K block */

107 - offs += 32*1024 + 18; /* Add 32K + 18 bytes slack */

108 + offs += 64*1024 + 128; /* Add 64K + 128 bytes slack */

109 offs = (offs+4095) & ~4095; /* Round to a 4K boundary */

110

111 printf(".section \".rodata..compressed\",\"a\",@progbits\n");

112 diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h

113 index 3b62ab5..5e1a2ee 100644

114 --- a/arch/x86/include/asm/boot.h

115 +++ b/arch/x86/include/asm/boot.h

116 @@ -32,11 +32,7 @@

117 #define BOOT_HEAP_SIZE 0x400000

118 #else /* !CONFIG_KERNEL_BZIP2 */

119

120 -#ifdef CONFIG_X86_64

121 -#define BOOT_HEAP_SIZE 0x7000

122 -#else

123 -#define BOOT_HEAP_SIZE 0x4000

124 -#endif

125 +#define BOOT_HEAP_SIZE 0x8000

126

127 #endif /* !CONFIG_KERNEL_BZIP2 */

128