EMILE/second/head.S

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/*
*
* (c) 2004, 2005 Laurent Vivier <Laurent@lvivier.info>
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*
*/
.cpu 68000
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.macro SysError
.short 0xA9C9
.endm
.macro NewPtrClear
.short 0xA31E
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.endm
.equ paramstring_length, 1024
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/***************************************************************************
*
* second level arguments
*
***************************************************************************/
_start: bra setup
_signature: .dc.b 'E','M','0','7'
/* EM06 */
_conf_size: .dc.w paramstring_length
_configuration: .skip paramstring_length, 0
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.align 4
setup:
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/* relocate C code, need to be compiled with -fpic */
bsr relocate
/* initialize console, so we can debug ;-) */
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lea _start(%pc), %a0
move.l %a0, -(%sp)
bsr console_init@PLTPC
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/* begin to work */
lea _start(%pc), %a0
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move.l %a0, -(%sp)
bsr start@PLTPC
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/* We guess to never come here */
loop:
bra loop
relocate:
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/* Allocate BSS section */
move.l #__bss_size, %d0 /* size */
/* Alloc and clear memory (needed by GCC 3) */
NewPtrClear /* result in %a0 */
move.l %a0, %d0
bne malloc_ok
SysError
malloc_ok:
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move.l %a0,%d3
move.l #__bss_start, %d0
sub.l %d0,%d3 /* %d3 is the offset to add for BSS */
/* real address of GOT */
lea _GLOBAL_OFFSET_TABLE_-.-8,%a0
lea (%pc, %a0), %a0
/* linked address of GOT */
move.l #_GLOBAL_OFFSET_TABLE_, %d0
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/* %d2 is the offset to add for all other sections */
move.l %a0,%d2
sub.l %d0,%d2
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/* relocate BSS section */
move.l #__got_size, %d0
beq exit_relocate
got_loop:
move.l (%a0), %d1
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cmp.l #__bss_start.l, %d1
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blt other_section
cmp.l #_end.l, %d1
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bgt other_section
/* symbol in section BSS */
add.l %d3, %d1
bra got_store
other_section:
add.l %d2, %d1
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got_store:
move.l %d1, (%a0)+
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subq.l #4, %d0
bgt got_loop
exit_relocate:
rts