diff options
Diffstat (limited to 'newlib/libc/sys/go32/crt0.S')
| -rw-r--r-- | newlib/libc/sys/go32/crt0.S | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/newlib/libc/sys/go32/crt0.S b/newlib/libc/sys/go32/crt0.S new file mode 100644 index 000000000..5fc6cf77c --- /dev/null +++ b/newlib/libc/sys/go32/crt0.S @@ -0,0 +1,233 @@ + +/* +** Called as start(argc, argv, envp) +*/ + +/* gs:edx points to prog_info structure. All other registers are OBSOLETE +** but included for backwards compatibility +*/ + +/* These symbols are for global constructors and destructors */ +#if 0 + .section .ctor + .globl ___go32_first_ctor +___go32_first_ctor: + .section .dtor + .globl ___go32_last_ctor +___go32_last_ctor: + .globl ___go32_first_dtor +___go32_first_dtor: + .data + .globl ___go32_last_dtor +___go32_last_dtor: +#endif + .text + .globl _start +_start: + .globl start +start: +#ifdef EMU387 + pusha + push %gs +#endif + movl %eax,__hard_master + movl %esi,___pid + movl %edi,___transfer_buffer + movl %ebx,_ScreenPrimary + movl %ebp,_ScreenSecondary + + cmpl $0, %edx + je Lcopy_none + movw %gs,%cx + movw %ds,%ax + cmpw %cx,%ax + je Lcopy_none + + movl %gs:(%edx), %ecx + cmpl __go32_info_block, %ecx + jbe Lcopy_less + movl __go32_info_block, %ecx +Lcopy_less: + movl $__go32_info_block, %edi + addl $3, %ecx + andl $0xfffffffc, %ecx + movl %ecx, (%edi) + addl $4, %edi + addl $4, %edx + subl $4, %ecx +Lcopy_more: + movl %gs:(%edx), %eax + movl %eax, (%edi) + addl $4, %edx + addl $4, %edi + subl $4, %ecx + jnz Lcopy_more + + movl __go32_info_block+4, %eax + movl %eax, _ScreenPrimary + movl __go32_info_block+8, %eax + movl %eax, _ScreenSecondary +/* Backward compatibility - do not copy this one! +** movl __go32_info_block+12, %eax +** movl %eax, ___transfer_buffer +*/ + movl __go32_info_block+20, %eax + movl %eax, ___pid + movl __go32_info_block+24, %eax + movl %eax, __hard_master + + jmp Lcopy_done + +Lcopy_none: + movl %ebx,__go32_info_block+4 + movl %ebp,__go32_info_block+8 + movl %edi,__go32_info_block+12 + movl $4096,__go32_info_block+16 + movl %esi,__go32_info_block+20 + movl %eax,__go32_info_block+24 + movl $28, __go32_info_block +Lcopy_done: + +#ifndef EMU387 + call __setstack +#endif + xorl %esi,%esi + xorl %edi,%edi + xorl %ebp,%ebp + xorl %ebx,%ebx + + movl %esp,%ebx +#ifdef MAKE_GCRT0 + call mcount_init /* initialize the profiler */ +#endif + movl 8(%ebx),%eax + pushl %eax + movl %eax,_environ + pushl 4(%ebx) + pushl (%ebx) + call ___main + call _main + addl $12,%esp +#ifdef EMU387 + pop %gs + popa +#else + pushl %eax + call _exit + +exit_again: + movl $0x4c00,%eax + int $0x21 + jmp exit_again +#endif + + ret + + +#ifdef MAKE_GCRT0 + .globl __exit +__exit: + call mcount_write /* make sure we dump the output */ +exit_again2: + movb 4(%esp),%al + movb $0x4c,%ah + int $0x21 + jmp exit_again2 + +/* Here is where we initialize the timer interrupt - specific to go32 */ +/* In this case, the timer calls mcount_isr */ + .globl mcount_isr_init +mcount_isr_init: + movw __go32_info_block+36, %ax /* run mode */ + cmp $1,%ax + jb skip_mcount + cmp $3,%ax + ja skip_mcount + + movw $16,%ax + movw %ax,%gs + + movzbl __hard_master,%eax /* timer is on irq 0 */ + shll $3,%eax /* times 8 bpv */ +/* movl $960,%eax vector 0x78 * 8 bpv */ + movw %gs:(%eax),%cx + movw %cx,mc_chain + movw %gs:6(%eax),%cx + movw %cx,mc_chain_hi + movw %gs:2(%eax),%cx + movw %cx,mc_chain_sel + + movl $mcount_isr,%ecx + movw %cx,%gs:(%eax) + movw $0xd8,%gs:2(%eax) /* selector 27 == 32-bit code */ + movw $0x8f00,%gs:4(%eax) + rorl $16,%ecx + movw %cx,%gs:6(%eax) + movw %ds,%ax + movw %ax,%gs +skip_mcount: + movl mcount_histogram,%eax + movl $1,(%eax) + ret + +/* Obtain the PC where we interrupted, and bump the histogram. We should */ +/* do error checking here, but we don't. This routine is specific to go32 */ +/* in some spots */ +mcount_isr: + pushl %eax + cmpl $1,mcount_skip + je L0 + movl 4(%esp),%eax /* get the PC */ + subl $0x1020,%eax /* to fit in low..high */ + andl $0xfffffffc,%eax + shrl $1,%eax /* now points to one 4-byte entry */ + addl mcount_histogram,%eax + incw (%eax) +L0: + popl %eax + ljmp mc_chain /* chain to the next timer vector */ + iret +#endif + + .data + + .globl _environ +_environ: + .long 0 + + .globl ___pid +___pid: + .long 42 + + .globl ___transfer_buffer +___transfer_buffer: + .long 0 + + .globl _ScreenPrimary +_ScreenPrimary: + .long 0 + + .globl _ScreenSecondary +_ScreenSecondary: + .long 0 + + .globl __hard_master + .globl __hard_slave + .globl __core_select +__hard_master: + .byte 0 +__hard_slave: + .byte 0 +__core_select: + .short 0 + +#ifdef MAKE_GCRT0 +mc_chain: + .short 0 +mc_chain_hi: + .short 0 +mc_chain_sel: + .short 0 +#endif + + |