fpc/rtl/msdos/prt0comn.asm
nickysn 46b82e3208 + added the necessary changes for section based smartlinking to the msdos
startup code, behind ifdef __I8086_SMARTLINK_SECTIONS__

git-svn-id: trunk@39278 -
2018-06-22 15:42:19 +00:00

791 lines
17 KiB
NASM

; common startup code for all the memory models
; uncomment this, if you want to use i8086 section based smartlinking:
;%define __I8086_SMARTLINK_SECTIONS__
%ifdef __TINY__
%define __NEAR_CODE__
%define __NEAR_DATA__
%elifdef __SMALL__
%define __NEAR_CODE__
%define __NEAR_DATA__
%elifdef __MEDIUM__
%define __FAR_CODE__
%define __NEAR_DATA__
%elifdef __COMPACT__
%define __NEAR_CODE__
%define __FAR_DATA__
%elifdef __LARGE__
%define __FAR_CODE__
%define __FAR_DATA__
%elifdef __HUGE__
%define __FAR_CODE__
%define __FAR_DATA__
%else
%fatal "Memory model not defined."
%endif
%ifdef __FAR_CODE__
extra_param_offset equ 2
%else
extra_param_offset equ 0
%endif
%ifdef __FAR_DATA__
extra_data_offset equ 2
%else
extra_data_offset equ 0
%endif
cpu 8086
segment _TEXT use16 class=CODE
extern PASCALMAIN
extern __fpc_PrefixSeg
extern dos_version
extern __Test8086
extern _edata ; defined by WLINK, indicates start of BSS
extern _end ; defined by WLINK, indicates end of BSS
extern __stklen
extern __stktop
extern __stkbottom
extern __nearheap_start
extern __nearheap_end
extern ___heap
%ifdef __NEAR_DATA__
extern __fpc_stackplusmaxheap_in_para
%endif
%ifndef __TINY__
%ifdef __FAR_DATA__
extern ___stack
%endif
%ifdef __NEAR_DATA__
extern ___stacktop
%endif
%endif
extern __SaveInt00
extern __SaveInt10
extern __SaveInt75
extern __fpu_status
extern FPC_HANDLE_I8086_ERROR
%ifdef __TINY__
resb 0100h
%endif
..start:
%ifndef __HUGE__
%ifdef __TINY__
mov bx, cs
%else
mov bx, DGROUP
%ifdef __NEAR_DATA__
; init the stack
mov ss, bx
mov sp, ___stacktop wrt DGROUP
%endif
%endif
; zero fill the BSS section
mov es, bx
mov di, _edata wrt DGROUP
mov cx, _end wrt DGROUP
sub cx, di
xor al, al
cld
rep stosb
%endif ; not __HUGE__
; save the Program Segment Prefix
push ds
; init DS
%ifdef __HUGE__
mov bx, SYSTEM_DATA
mov ds, bx
%else
mov ds, bx
%endif
; pop the PSP from stack and store it in the pascal variable PrefixSeg
pop ax
mov word [__fpc_PrefixSeg], ax
; get DOS version and save it in the pascal variable dos_version
mov ax, 3000h
int 21h
xchg al, ah
mov word [dos_version], ax
; detect CPU
xor bx, bx ; 0=8086/8088/80186/80188/NEC V20/NEC V30
; on pre-286 processors, bits 12..15 of the FLAGS registers are always set
pushf
pop ax
and ah, 0fh
push ax
popf
pushf
pop ax
and ah, 0f0h
cmp ah, 0f0h
je cpu_detect_done
; at this point we have a 286 or higher
inc bx
; on a true 286 in real mode, bits 12..15 are always clear
pushf
pop ax
or ah, 0f0h
push ax
popf
pushf
pop ax
and ah, 0f0h
jz cpu_detect_done
; we have a 386+
inc bx
cpu_detect_done:
mov [__Test8086], bl
%ifdef __NEAR_DATA__
; ****************************************************************************
; ** near data memory layout setup **
; ****************************************************************************
; allocate max heap
; first we determine in paragraphs ax:=min(64kb, data+bss+stack+maxheap)
mov ax, _end wrt DGROUP
add ax, 15
mov cl, 4
shr ax, cl
add ax, word [__fpc_stackplusmaxheap_in_para]
cmp ax, 1000h ; 1000h = 64k in paragraphs
jbe data_with_maxheap_less_than_64k
mov ax, 1000h
data_with_maxheap_less_than_64k:
; try to resize our main DOS memory block until the end of the data segment (or even smaller, if maxheap is small)
mov cx, word [__fpc_PrefixSeg]
%ifdef __TINY__
mov dx, cs
%else
mov dx, DGROUP
%endif
sub dx, cx ; dx = (ds - psp) in paragraphs
push dx ; save (ds - psp)
add dx, 1000h ; 64kb in paragraphs
; get our MCB size in paragraphs
dec cx
mov es, cx
mov bx, word [es:3]
; is it smaller than the maximum data segment size?
cmp bx, dx
jbe skip_mem_realloc
mov bx, dx
inc cx
mov es, cx
mov ah, 4Ah
int 21h
jc mem_realloc_err
skip_mem_realloc:
; bx = the new size in paragraphs
pop cx ; cx = (ds - psp)
sub bx, cx
mov cl, 4
shl bx, cl
sub bx, 2
mov sp, bx
mov word [__stktop], sp
add bx, 2
sub bx, word [__stklen]
and bl, 0FEh
mov word [__stkbottom], bx
mov ax, _end wrt DGROUP
cmp bx, ax
jb not_enough_mem
; heap is between [ds:_end wrt DGROUP] and [ds:__stkbottom - 1]
add ax, 3
and al, 0FCh
mov word [__nearheap_start], ax
and bl, 0FCh
mov word [__nearheap_end], bx
; ****************************************************************************
; ** near data setup done **
; ****************************************************************************
%endif
%ifdef __FAR_DATA__
mov word [__stktop], sp
mov word [__stkbottom], 0
mov ax, ss
mov word [__stkbottom + 2], ax
mov word [__stktop + 2], ax
mov dx, sp
add dx, 15
mov cl, 4
shr dx, cl
add ax, dx
mov word [__nearheap_start], 0
mov word [__nearheap_start + 2], ax
; get our MCB size in paragraphs
mov cx, word [__fpc_PrefixSeg]
dec cx
mov es, cx
mov bx, word [es:3]
add bx, cx
inc bx
; __nearheap_end := end_of_dos_memory_block
mov word [__nearheap_end], 0
mov word [__nearheap_end + 2], bx
%endif
%ifdef __FAR_CODE__
jmp far PASCALMAIN
%else
jmp PASCALMAIN
%endif
%ifdef __NEAR_DATA__
not_enough_mem:
mov dx, not_enough_mem_msg
jmp error_msg
mem_realloc_err:
; at this point there's still (ds-psp) pushed on the stack, but we won't
; bother popping it, because we exit to DOS with an error message here
mov dx, mem_realloc_err_msg
error_msg:
mov ah, 9
int 21h
mov ax, 4CFFh
int 21h
%endif
global FPC_INT00_HANDLER
FPC_INT00_HANDLER:
pushf
sub sp, 4 ; reserve space on the stack for the iret
push cx
push ds
push bp
; init ds
%ifdef __TINY__
mov bp, cs
%elifdef __HUGE__
mov bp, SYSTEM_DATA
%else
mov bp, DGROUP
%endif
mov ds, bp
%ifdef __NEAR_DATA__
; in memory models, where SS=DS, also
; check whether we're running on the same stack
mov cx, ss
cmp bp, cx
jne .call_previous_handler00
%endif
%ifndef __FAR_CODE__
; check whether we're coming from the same code segment
mov bp, sp
mov cx, [bp + 3*2 + 6 + 2] ; get caller segment
mov bp, cs
cmp bp, cx
jne .call_previous_handler00
%endif
; Call Fpc_Handle_I8086_Error, with err=0
mov bp, sp
mov cx, [bp + 3*2 + 6] ; get caller offset
%ifdef __FAR_CODE__
mov dx, [bp + 3*2 + 6 + 2] ; get caller segment
%endif
pop bp
add sp, 2*2 + 6 + 6
xor ax, ax
push ax
mov ax, 0
push ax
%ifdef __FAR_CODE__
push dx
%endif
push cx
cld
sti
%ifdef __FAR_CODE__
jmp far FPC_HANDLE_I8086_ERROR
%else
jmp FPC_HANDLE_I8086_ERROR
%endif
.call_previous_handler00:
mov bp, sp
mov cx, [__SaveInt00]
mov [bp + 3*2], cx
mov cx, [__SaveInt00+2]
mov [bp + 3*2 + 2], cx
pop bp
pop ds
pop cx
iret ; jumps to the previous handler with all registers and stack intact
global FPC_INT10_HANDLER
FPC_INT10_HANDLER:
pushf
sub sp, 4 ; reserve space on the stack for the iret
push cx
push ds
push bp
; init ds
%ifdef __TINY__
mov bp, cs
%elifdef __HUGE__
mov bp, SYSTEM_DATA
%else
mov bp, DGROUP
%endif
mov ds, bp
; Check that an unmasked exception is indeed set
fnstsw word [__fpu_status]
test byte [__fpu_status], 80h ; really just this bit is enough, see i8087 datasheet
je .call_previous_handler10
%ifdef __NEAR_DATA__
; in memory models, where SS=DS, also
; check whether we're running on the same stack
mov cx, ss
cmp bp, cx
jne .call_previous_handler10
%endif
%ifndef __FAR_CODE__
; check whether we're coming from the same code segment
mov bp, sp
mov cx, [bp + 3*2 + 6 + 2] ; get caller segment
mov bp, cs
cmp bp, cx
jne .call_previous_handler10
%endif
; Call Fpc_Handle_I8086_Error, with err=$10
mov bp, sp
mov cx, [bp + 3*2 + 6] ; get caller offset
%ifdef __FAR_CODE__
mov dx, [bp + 3*2 + 6 + 2] ; get caller segment
%endif
pop bp
add sp, 2*2 + 6 + 6
xor ax, ax
push ax
mov ax, 10h
push ax
%ifdef __FAR_CODE__
push dx
%endif
push cx
cld
sti
%ifdef __FAR_CODE__
jmp far FPC_HANDLE_I8086_ERROR
%else
jmp FPC_HANDLE_I8086_ERROR
%endif
.call_previous_handler10:
mov bp, sp
mov cx, [__SaveInt10]
mov [bp + 3*2], cx
mov cx, [__SaveInt10+2]
mov [bp + 3*2 + 2], cx
pop bp
pop ds
pop cx
iret ; jumps to the previous handler with all registers and stack intact
global FPC_INT75_HANDLER
FPC_INT75_HANDLER:
pushf
sub sp, 4 ; reserve space on the stack for the iret
push cx
push ds
push bp
; init ds
%ifdef __TINY__
mov bp, cs
%elifdef __HUGE__
mov bp, SYSTEM_DATA
%else
mov bp, DGROUP
%endif
mov ds, bp
%ifdef __NEAR_DATA__
; in memory models, where SS=DS, also
; check whether we're running on the same stack
mov cx, ss
cmp bp, cx
jne .call_previous_handler75
%endif
%ifndef __FAR_CODE__
; check whether we're coming from the same code segment
mov bp, sp
mov cx, [bp + 3*2 + 6 + 2] ; get caller segment
mov bp, cs
cmp bp, cx
jne .call_previous_handler75
%endif
; Call Fpc_Handle_I8086_Error, with err=$75
mov bp, sp
mov cx, [bp + 3*2 + 6] ; get caller offset
%ifdef __FAR_CODE__
mov dx, [bp + 3*2 + 6 + 2] ; get caller segment
%endif
pop bp
add sp, 2*2 + 6 + 6
xor ax, ax
push ax
mov ax, 75h
push ax
%ifdef __FAR_CODE__
push dx
%endif
push cx
cld
; Reset IRQ/#IGNNE latch; signal EOI; enable interrupts
mov al,20h
out 0F0h,al ; al=any
out 0A0h,al
out 020h,al
sti
%ifdef __FAR_CODE__
jmp far FPC_HANDLE_I8086_ERROR
%else
jmp FPC_HANDLE_I8086_ERROR
%endif
.call_previous_handler75:
mov bp, sp
mov cx, [__SaveInt75]
mov [bp + 3*2], cx
mov cx, [__SaveInt75+2]
mov [bp + 3*2 + 2], cx
pop bp
pop ds
pop cx
retf ; jumps to the previous handler with all registers and stack intact
global FPC_INSTALL_INTERRUPT_HANDLERS
FPC_INSTALL_INTERRUPT_HANDLERS:
%ifdef __HUGE__
push ds
mov ax, SYSTEM_DATA
mov ds, ax
%endif
; save old int 00 handler
mov ax, 3500h
int 21h
mov [__SaveInt00], bx
mov bx, es
mov [__SaveInt00+2], bx
; install the new int 00 handler
%ifndef __TINY__
push ds
push cs
pop ds
%endif
mov dx, FPC_INT00_HANDLER
mov ax, 2500h
int 21h
%ifndef __TINY__
pop ds
%endif
; save old int $10 handler
mov ax, 3510h
int 21h
mov [__SaveInt10], bx
mov bx, es
mov [__SaveInt10+2], bx
; install the new int $10 handler
%ifndef __TINY__
push ds
push cs
pop ds
%endif
mov dx, FPC_INT10_HANDLER
mov ax, 2510h
int 21h
%ifndef __TINY__
pop ds
%endif
; save old int $75 handler
mov ax, 3575h
int 21h
mov [__SaveInt75], bx
mov bx, es
mov [__SaveInt75+2], bx
; install the new int $75 handler
%ifndef __TINY__
push ds
push cs
pop ds
%endif
mov dx, FPC_INT75_HANDLER
mov ax, 2575h
int 21h
%ifndef __TINY__
pop ds
%endif
%ifdef __HUGE__
pop ds
%endif
%ifdef __FAR_CODE__
retf
%else
ret
%endif
global FPC_RESTORE_INTERRUPT_HANDLERS
FPC_RESTORE_INTERRUPT_HANDLERS:
%ifdef __HUGE__
push ds
mov ax, SYSTEM_DATA
mov ds, ax
%endif
push ds
mov ax, 2500h
lds dx, [__SaveInt00]
int 21h
pop ds
push ds
mov ax, 2510h
lds dx, [__SaveInt10]
int 21h
pop ds
push ds
mov ax, 2575h
lds dx, [__SaveInt75]
int 21h
pop ds
%ifdef __HUGE__
pop ds
%endif
%ifdef __FAR_CODE__
retf
%else
ret
%endif
global FPC_MSDOS_CARRY
FPC_MSDOS_CARRY:
stc
global FPC_MSDOS
FPC_MSDOS:
mov al, 21h ; not ax, because only the low byte is used
pop dx
%ifdef __FAR_CODE__
pop bx
%endif
pop cx
%ifdef __FAR_DATA__
pop si
%endif
push ax
%ifdef __FAR_DATA__
push si
%endif
push cx
%ifdef __FAR_CODE__
push bx
%endif
push dx
global FPC_INTR
FPC_INTR:
push bp
mov bp, sp
mov al, byte [bp + 6 + extra_param_offset + extra_data_offset]
mov byte [cs:int_number], al
mov si, [bp + 4 + extra_param_offset]
push ds
%ifdef __FAR_DATA__
mov ax, [bp + 6 + extra_param_offset]
mov ds, ax
%endif
mov ax, word [si + 16]
mov es, ax
mov ax, word [si + 14] ; ds
push ax
mov ax, word [si]
mov bx, word [si + 2]
mov cx, word [si + 4]
mov dx, word [si + 6]
mov bp, word [si + 8]
mov di, word [si + 12]
mov si, word [si + 10]
pop ds
db 0CDh ; opcode of INT xx
int_number:
db 255
pushf
push ds
push si
push bp
mov bp, sp
%ifdef __FAR_DATA__
mov si, [bp + 16 + extra_param_offset]
%else
mov si, word [bp + 8]
%endif
mov ds, si
mov si, word [bp + 14 + extra_param_offset]
mov word [si], ax
mov word [si + 2], bx
mov word [si + 4], cx
mov word [si + 6], dx
mov word [si + 12], di
mov ax, es
mov word [si + 16], ax
pop ax
mov word [si + 8], ax
pop ax
mov word [si + 10], ax
pop ax
mov word [si + 14], ax
pop ax
mov word [si + 18], ax
pop ds
pop bp
%ifdef __FAR_CODE__
retf 4 + extra_data_offset
%else
ret 4 + extra_data_offset
%endif
%ifndef __TINY__
global FPC_CHECK_NULLAREA
FPC_CHECK_NULLAREA:
%ifdef __HUGE__
mov ax, DGROUP
mov es, ax
%else
push ds
pop es
%endif
xor di, di
mov cx, 32
mov al, 1
cld
repe scasb
je .skip
dec ax ; 1 byte shorter than dec al
.skip:
%ifdef __FAR_CODE__
retf
%else
ret
%endif
%endif
%ifdef __HUGE__
; reference the system unit's data segment
segment SYSTEM_DATA use16 class=FAR_DATA align=2
%endif
segment data class=DATA align=2
%ifdef __NEAR_DATA__
mem_realloc_err_msg:
db 'Memory allocation error', 13, 10, '$'
not_enough_mem_msg:
db 'Not enough memory', 13, 10, '$'
%endif
; add reference to the beginning of the minimal heap, so the object
; module, containing the heap segment doesn't get smartlinked away
dw ___heap
segment bss class=BSS align=2
%ifndef __TINY__
segment _NULL align=16 class=BEGDATA
global __nullarea
__nullarea:
dd 01010101h, 01010101h, 01010101h, 01010101h
dd 01010101h, 01010101h, 01010101h, 01010101h
segment _AFTERNULL align=2 class=BEGDATA
dw 0
%ifdef __NEAR_DATA__
segment stack stack class=STACK align=16
%else
segment data
; add reference to the beginning of stack, so the object module,
; containing the stack segment doesn't get smartlinked away
dw ___stack
%endif
%endif
%ifdef __TINY__
group DGROUP _TEXT data bss
%else
%ifdef __NEAR_DATA__
group DGROUP _NULL _AFTERNULL data bss stack
%else
group DGROUP _NULL _AFTERNULL data bss
%endif
%ifdef __I8086_SMARTLINK_SECTIONS__
group CGROUP _TEXT
%endif
%endif