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| author | Till Straumann <strauman@slac.stanford.edu> | 2009-10-29 03:22:19 +0000 |
|---|---|---|
| committer | Till Straumann <strauman@slac.stanford.edu> | 2009-10-29 03:22:19 +0000 |
| commit | 23303c031115e9506952cc1e3f3683b270dc6c0d (patch) | |
| tree | 1ea111c73e49c307accfd0352336562950c949e5 /c/src/lib/libbsp/i386/pc386/start/start.S | |
| parent | 2009-10-29 Ralf Corsépius <ralf.corsepius@rtems.org> (diff) | |
| download | rtems-23303c031115e9506952cc1e3f3683b270dc6c0d.tar.bz2 | |
2009-10-28 Till Straumann <strauman@slac.stanford.edu>
* start/start.S: Make sure initial stack is aligned
to CPU_STACK_ALIGNMENT before calling C-code.
Diffstat (limited to '')
| -rw-r--r-- | c/src/lib/libbsp/i386/pc386/start/start.S | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/c/src/lib/libbsp/i386/pc386/start/start.S b/c/src/lib/libbsp/i386/pc386/start/start.S index 373c2d7658..ad71ccdf31 100644 --- a/c/src/lib/libbsp/i386/pc386/start/start.S +++ b/c/src/lib/libbsp/i386/pc386/start/start.S @@ -42,11 +42,16 @@ */ #include <rtems/asm.h> +#include <rtems/score/cpu.h> /*----------------------------------------------------------------------------+ | Size of heap and stack: +----------------------------------------------------------------------------*/ +#ifndef CPU_STACK_ALIGNMENT +#error "Missing header ? CPU_STACK_ALIGNMENT NOT DEFINED" +#endif + .set STACK_SIZE, 0x1000 /*----------------------------------------------------------------------------+ @@ -164,7 +169,8 @@ SYM (_establish_stack): movl $_end, eax # eax = end of bss/start of heap addl $STACK_SIZE, eax # make room for stack - andl $0xffffffc0, eax # align it on 16 byte boundary + subl $4, eax # reserve room for arg to 'boot_card' + andl $ - CPU_STACK_ALIGNMENT, eax # align SP on CPU_STACK_ALIGNMENT boundary movl eax, esp # set stack pointer movl eax, ebp # set base pointer @@ -197,12 +203,17 @@ SYM (zero_bss): /*---------------------------------------------------------------------+ | Transfer control to User's Board Support Package +| Note: at the top we reserved space for the argument +| so that +| initial_esp = ( TOS - 4 ) & ~(CPU_STACK_ALIGNMENT-1) +| this ensures that +| 1) esp is now aligned +| 2) there is space for the cmdline pointer which we just +| may store at *(esp) +---------------------------------------------------------------------*/ - movl $SYM(_boot_multiboot_cmdline), eax - pushl eax # cmdline + movl $SYM(_boot_multiboot_cmdline), (esp) call SYM (boot_card) - addl $4, esp /*---------------------------------------------------------------------+ | Clean up - we do not know anything about it, so we will |