minix/lib/i386/rts/prtso.s
2005-04-21 14:53:53 +00:00

69 lines
1.7 KiB
ArmAsm
Executable file

! This is the Pascal run-time start-off routine. It's job is to take the
! arguments as put on the stack by EXEC, and to parse them and set them up the
! way _m_a_i_n expects them.
.sect .text; .sect .rom; .sect .data; .sect .bss
.define begtext, begdata, begbss
.sect .text
begtext:
.sect .rom
begrom:
.sect .data
begdata:
.sect .bss
begbss:
.define prtso, hol0, __penviron, __penvp, __fpu_present
.sect .text
prtso:
xor ebp, ebp ! clear for backtrace of core files
mov eax, (esp) ! argc
lea edx, 4(esp) ! argv
lea ecx, 8(esp)(eax*4) ! envp
! Test if environ is in the initialized data area and is set to our
! magic number. If so then it is not redefined by the user.
mov ebx, _environ
cmp ebx, __edata ! within initialized data?
jae 0f
testb bl, 3 ! aligned?
jnz 0f
cmp (ebx), 0x53535353 ! is it our environ?
jne 0f
mov (__penviron), ebx ! _penviron = &environ;
0: mov ebx, (__penviron)
mov (ebx), ecx ! *_penviron = envp;
push ecx ! push envp
push edx ! push argv
push eax ! push argc
! Test the EM bit of the MSW to determine if an FPU is present and
! set __fpu_present if one is found.
smsw ax
testb al, 0x4 ! EM bit in MSW
setz (__fpu_present) ! True if not set
mov (.ignmask), 56
call __m_a_i_n ! Run Pascal program
push eax ! push exit status
call __exit
hlt ! force a trap if exit fails
.sect .rom
.data4 0 ! Separate I&D: *NULL == 0
! Also keeps the first string in the
! program from appearing at location 0!
.sect .data
__penviron:
.data4 __penvp ! Pointer to environ, or hidden pointer
.sect .bss
.comm __penvp, 4 ! Hidden environment vector
.comm __fpu_present, 4 ! FPU present flag
.extern endtext ! Force loading of end labels.