Zero BSS in hello world test

While trying to reduce U/X state issues, I notice that our BSS is not
being initialised in the hello world test.

Signed-off-by: Anton Blanchard <anton@linux.ibm.com>

diff --git a/hello_world/head.S b/hello_world/head.S
index 63576063f040c707d307a6c0ea4216e16f3f2da9..15f3494f7799637fc38deaefe1bb551903e0a186 100644 (file)
--- a/hello_world/head.S
+++ b/hello_world/head.S
@@ -60,11 +60,25 @@ _start:
 
 .global boot_entry
 boot_entry:
+       LOAD_IMM64(%r10,__bss_start)
+       LOAD_IMM64(%r11,__bss_end)
+       subf    %r11,%r10,%r11
+       addi    %r11,%r11,63
+       srdi.   %r11,%r11,6
+       beq     2f
+       mtctr   %r11
+1:     dcbz    0,%r10
+       addi    %r10,%r10,64
+       bdnz    1b
+
        /* setup stack */
-       LOAD_IMM64(%r1, STACK_TOP - 0x100)
+2:     LOAD_IMM64(%r1,__stack_top)
+       li      %r0,0
+       stdu    %r0,-32(%r1)
        LOAD_IMM64(%r12, main)
-       mtctr   %r12,
+       mtctr   %r12
        bctrl
+       attn // terminate on exit
        b .
 
 #define EXCEPTION(nr)          \

diff --git a/hello_world/hello_world.bin b/hello_world/hello_world.bin
index e4b14ca6f70843d9d43a149c8d18fb1f22072fe5..a4eb88c26f7c7742bc5d42c1d9c571302a03b69f 100755 (executable)
Binary files a/hello_world/hello_world.bin and b/hello_world/hello_world.bin differ

diff --git a/hello_world/hello_world.elf b/hello_world/hello_world.elf
index 5eeedc452464d33864fa4a2deb5dd10f5eccbfd1..3dc0cc1c1cb753a5fe02cfa05c9860ff01c29675 100755 (executable)
Binary files a/hello_world/hello_world.elf and b/hello_world/hello_world.elf differ

diff --git a/hello_world/hello_world.hex b/hello_world/hello_world.hex
index 763797e40515898838548e23915bda31144e8b57..c0161ad4a52e2cb5fbfb8748492ba9888575889a 100644 (file)
--- a/hello_world/hello_world.hex
+++ b/hello_world/hello_world.hex
@@ -35,24 +35,24 @@ a64b5a7d14004a39
 a602487d05009f42
 a64b5a7d14004a39
 2402004ca64b7b7d
-3c20000048000004
+3d40000048000004
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+7d6a5850616b1980
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 782107c660210000
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-0000000000000000
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+6021398064210000
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+4800000000000200
 0000000000000000
 0000000000000000
 0000000000000000
@@ -510,150 +510,150 @@ a64b5a7d14004a39
 0000000000000000
 0000000000000000
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-0000000000000000
 384298003c400001
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 f821ffd1f8010010
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 000000004bffffd0
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-0000000000000000
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 0000000000000000
 3c40000100000000
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 0000000000000000
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diff --git a/hello_world/powerpc.lds b/hello_world/powerpc.lds
index 96bc6b9b16120335e73f6e90c29b3573d2c55e59..1e218c7a431debd3cbd4f1f8bed6392ce288e882 100644 (file)
--- a/hello_world/powerpc.lds
+++ b/hello_world/powerpc.lds
@@ -1,13 +1,27 @@
 SECTIONS
 {
-       _start = .;
        . = 0;
+       _start = .;
        .head : {
                KEEP(*(.head))
-       }
+       }
        . = 0x1000;
-       .text : { *(.text) }
+       .text : { *(.text) *(.text.*) *(.rodata) *(.rodata.*) }
        . = 0x1800;
-       .data : { *(.data) }
-       .bss : { *(.bss) }
+       .data : { *(.data) *(.data.*) *(.got) *(.toc) }
+       . = ALIGN(0x80);
+       __bss_start = .;
+       .bss : {
+               *(.dynsbss)
+               *(.sbss)
+               *(.scommon)
+               *(.dynbss)
+               *(.bss)
+               *(.common)
+               *(.bss.*)
+       }
+       . = ALIGN(0x80);
+       __bss_end = .;
+       . = . + 0x2000;
+       __stack_top = .;
 }