wok annotate linld/stuff/src/_BEG.ASM @ rev 21984

linld: x86 support
author Pascal Bellard <pascal.bellard@slitaz.org>
date Mon Oct 14 11:20:06 2019 +0200 (2019-10-14)
parents d8f824013cf6
children 5b6c86ca3faa
rev   line source
pascal@19515 1 ;***************************************************************
pascal@19515 2 ;****** This file is distributed under GPL
pascal@19515 3 ;***************************************************************
pascal@19515 4 ideal
pascal@21984 5 %PAGESIZE 1000
pascal@19515 6 %crefref
pascal@19515 7 %noincl
pascal@19515 8 %nomacs
pascal@19636 9 p8086
pascal@19515 10
pascal@19515 11 group DGROUP _TEXT,_DATA,_BSS
pascal@19515 12 assume cs:DGROUP,ds:DGROUP
pascal@19515 13
pascal@19515 14 segment _TEXT byte public use16 'CODE'
pascal@20451 15 ends _TEXT
pascal@20451 16
pascal@20451 17 segment _DATA byte public use16 'DATA'
pascal@20451 18 global _data_start:byte
pascal@20451 19 label _data_start byte
pascal@20451 20 ifndef NO386
pascal@20451 21 msg_badcpu db "I need 386+ CPU in real mode or under VCPI manager"
pascal@20451 22 endif
pascal@20451 23 global _vcpi:byte
pascal@20451 24 _vcpi db 0
pascal@20528 25 msg_badmapping db "VCPI: low 640k need 1:1 mapping",0
pascal@20451 26
pascal@20451 27 ends _DATA
pascal@20451 28
pascal@20451 29 segment _BSS byte public use16 'BSS'
pascal@21757 30
pascal@21757 31 STACK_SIZE = 1024
pascal@21757 32
pascal@20451 33 global _bss_start:byte
pascal@20451 34 label _bss_start byte
pascal@21757 35 db STACK_SIZE-2 dup(?)
pascal@21757 36 stktop dw ?
pascal@20451 37 global _cpu_features:dword
pascal@20451 38 _cpu_features dd ?
pascal@20451 39 ends _BSS
pascal@20451 40
pascal@20451 41 segment _TEXT byte public use16 'CODE'
pascal@19515 42
pascal@19825 43 macro cpuid
pascal@19825 44 db 0fh,0A2h
pascal@19825 45 endm
pascal@19825 46
pascal@19515 47 org 100h
pascal@19515 48 global _text_start:byte
pascal@19515 49 label _text_start byte
pascal@19546 50
pascal@19515 51 ;***************************************************************
pascal@19515 52 ; clear bss
pascal@19515 53 ;***************************************************************
pascal@21757 54 mov sp,offset stktop
pascal@21757 55 mov si,sp
pascal@20457 56 mov bx, 0F000h ; cld ; cli & empty string
pascal@19515 57 clearbss:
pascal@20451 58 mov [si],bl ; clear bss + heap + sp
pascal@20426 59 inc si
pascal@19546 60 jne clearbss
pascal@19546 61
pascal@19546 62 ;***************************************************************
pascal@19546 63 ; check CPU
pascal@19546 64 ;***************************************************************
pascal@19546 65
pascal@19546 66 ; Check for oldies
pascal@19873 67 push bx ; < 286 : flags[12..15] are forced 1
pascal@19873 68 popf ; = 286 : flags[12..15] are forced 0
pascal@19873 69 pushf ; > 286 : only flags[15] is forced 0
pascal@19873 70 pop dx
pascal@20451 71 add dh,bh ; NS=386+, S+NC=286, S+C=86/186
pascal@20451 72 ifndef NO386
pascal@19873 73 mov bx,offset msg_badcpu
pascal@20457 74 js godie ;it is not a 386+
pascal@20451 75 else
pascal@20457 76 js endcpu86 ;it is not a 386+
pascal@19546 77 endif
pascal@19636 78 p386
pascal@19546 79 ; Check for vm
pascal@19546 80 smsw ax ;SMSW cannot be trapped! :-)
pascal@19571 81 and al,1 ;MSW_PE
pascal@19546 82 ; We're in vm
pascal@20457 83 jnz check_vcpi
pascal@20457 84
pascal@20457 85 check_rm_paging:
pascal@20457 86 ; It's a 386 in real mode, chk for paging (crazy but possible)
pascal@20457 87 mov eax,cr0
pascal@20457 88 inc eax ;CR0_PG to S
pascal@20457 89 jns endcpu386
pascal@20457 90 no_vcpi:
pascal@20457 91 p8086
pascal@20457 92 extrn die:near
pascal@20457 93 godie:
pascal@20457 94 call near die
pascal@19546 95
pascal@19546 96 ;***************************************************************
pascal@19546 97 ; checks for vcpi
pascal@19546 98 ;***************************************************************
pascal@19546 99 label check_vcpi near
pascal@20457 100 p386
pascal@19546 101 push ds
pascal@19546 102 ; Check whether it is safe to call 67h (we trust only known EMM managers)
pascal@20426 103 push si
pascal@19546 104 pop ds
pascal@19546 105 mov ds,[word 67h*4+2]
pascal@20426 106 cmp [dword si+10+4],'0XXX'
pascal@19546 107 jne skip
pascal@19825 108 ;mov eax,'XMME'
pascal@20426 109 ;xor eax,[dword si+10]
pascal@19546 110 ; QMME also works (as told by <J.S.Peatfield@damtp.cambridge.ac.uk>)
pascal@19825 111 ;shl eax,8
pascal@19825 112 mov ax,'ME'
pascal@20426 113 xor ax,[word si+10]
pascal@19546 114 skip:
pascal@19546 115 pop ds
pascal@19546 116 jne no_vcpi
pascal@19546 117
pascal@19546 118 ; Check emm manager status and version
pascal@19571 119 ;mov ah,40h ; get status
pascal@19571 120 ;int 67h
pascal@19571 121 ;test ah,ah
pascal@19571 122 ;jnz no_vcpi
pascal@19546 123 mov ah,46h ; get version
pascal@19546 124 int 67h
pascal@19546 125 test ah,ah
pascal@19546 126 jnz no_vcpi
pascal@19546 127 cmp al,40h ; version must be >= 4.0
pascal@19546 128 jb no_vcpi
pascal@19546 129 ; Check vcpi manager status
pascal@19546 130 ;;mov ax,5A01h ; ALLOCATE RAW PAGES
pascal@19546 131 ;;mov bx,4
pascal@19546 132 ;;int 67h
pascal@19546 133 ;;test ah,ah
pascal@19546 134 ;;jnz no_vcpi
pascal@19546 135 ;;push dx ;$ save handle
pascal@19546 136 mov ax,0DE00h ; check for vcpi present
pascal@19546 137 int 67h
pascal@19546 138 test ah,ah
pascal@19571 139 jnz no_vcpi
pascal@19546 140 is386vcpi:
pascal@19546 141 extrn prepare_vcpi:near
pascal@19546 142 call prepare_vcpi
pascal@19546 143 ; get_vcpi_interface() || die("VCPI: low 640k: need 1:1 mapping");
pascal@19546 144 ;extrn _get_vcpi_interface:near
pascal@19546 145 ;call _get_vcpi_interface
pascal@19546 146 mov bx,offset msg_badmapping
pascal@20457 147 jnz no_vcpi
pascal@21758 148 inc [byte bx+_vcpi-msg_badmapping]
pascal@20457 149 endcpu386:
pascal@20457 150 pushfd
pascal@20457 151 pop dx
pascal@20457 152 pop ax
pascal@20457 153 mov bl,al
pascal@20457 154 xor al,20h ; toggle CPUID feature bit 21
pascal@20457 155 push ax
pascal@20457 156 push dx
pascal@20457 157 popfd
pascal@20457 158 pushfd
pascal@20457 159 pop dx
pascal@20457 160 pop ax
pascal@20457 161 xor al,bl ; clear C
pascal@20457 162 je @@no_cpuid ; CPUID feature bit changed ?
pascal@20457 163 mov eax,80000001h ; Extended Processor Info and Feature Bits
pascal@20457 164 cpuid
pascal@20457 165 mov [_cpu_features],edx
pascal@20457 166 @@no_cpuid:
pascal@20457 167 endcpu86:
pascal@19636 168 p8086
pascal@19546 169
pascal@19515 170 ;***************************************************************
pascal@19515 171 ; build argv & argc
pascal@19515 172 ;***************************************************************
pascal@19546 173 extrn _heap_top:word
pascal@19546 174 mov di,[_heap_top]
pascal@19546 175 ;xor ax,ax
pascal@19546 176 ;push ax ; envp (already cleared)
pascal@19546 177 ;mov [word di],ax ; argv[0] = 0 (idem)
pascal@19515 178 mov si,80h
pascal@19515 179 lodsb
pascal@19515 180 cmp al,7Eh
pascal@19515 181 jbe alok
pascal@19515 182 mov al,7Eh
pascal@19515 183 alok:
pascal@19546 184 cbw
pascal@19515 185 xchg ax,bx
pascal@19515 186 mov [bx+si],bh ; set eos
pascal@19515 187 argbuild:
pascal@20160 188 ifdef DEBUG
pascal@20142 189 p386
pascal@20142 190 pusha
pascal@20142 191 mov bx,si
pascal@20142 192 extrn puts:near
pascal@20142 193 call puts
pascal@20142 194 popa
pascal@20160 195 endif
pascal@19515 196 mov bx,2 ; argc * 2
pascal@19515 197 argeos:
pascal@20451 198 mov cx,1 ; look for a start of string
pascal@19515 199 mov [byte si-1],bh ; mark eos
pascal@19515 200 mov ah,20h ; space will be eos
pascal@19515 201 arglp:
pascal@19515 202 lodsb
pascal@19515 203 cmp al,0h
pascal@19515 204 je argdone
pascal@19515 205 cmp al,20h
pascal@19515 206 jb argeos
pascal@19515 207 cmp al,ah
pascal@19515 208 je argeos
pascal@19515 209 cmp al,27h
pascal@19515 210 je isargstr
pascal@19515 211 cmp al,22h
pascal@19515 212 je isargstr
pascal@20451 213 jcxz arglp ; not start of string
pascal@19515 214 dec si
pascal@19884 215 ;jmp newarg
pascal@20451 216 db 0BAh ; mov dx,im opcode
pascal@19515 217 isargstr:
pascal@19515 218 mov ah,al ; expected eos
pascal@19515 219 newarg:
pascal@19515 220 mov [word bx+di],si ; argv[argc++] = si
pascal@19515 221 inc bx
pascal@19515 222 inc bx
pascal@20451 223 dec cx
pascal@19515 224 jmp arglp
pascal@19515 225 argdone:
pascal@19515 226 ;mov [word bx+di],0 ; argv[argc] = 0
pascal@19546 227 lea ax,[bx+di+2]
pascal@19546 228 mov [_heap_top],ax
pascal@19515 229 push di ; argv
pascal@19515 230 shr bx,1
pascal@19515 231 push bx ; argc
pascal@19515 232 ifndef filearg
pascal@19515 233 mov bx,[di+2] ; argv[1]
pascal@20528 234 extrn openargs:near
pascal@20528 235 call near openargs
pascal@19515 236 jc argend
pascal@19515 237 pop bx ; trash argc, argv >> 1Kb !
pascal@19546 238 global read_cmdline:near
pascal@20528 239 pop cx ; sizemax=argv
pascal@19546 240 read_cmdline:
pascal@20528 241 mov dx,di
pascal@20528 242 push dx
pascal@19515 243 push ax
pascal@20528 244 xchg ax,bx
pascal@20528 245 extrn @read$cxdxbx:near ; read(fd=bx,buffer=dx,size=cx)
pascal@20528 246 call near @read$cxdxbx
pascal@19515 247 pop bx ; fd for close
pascal@19515 248 pop si ; si=buffer=argv
pascal@19515 249 add di,ax
pascal@19515 250 extrn close:near
pascal@19515 251 call near close
pascal@19515 252 jmp argbuild
pascal@19515 253 argend:
pascal@19515 254 endif
pascal@19515 255
pascal@19515 256 ;***************************************************************
pascal@21757 257 extrn _main:near
pascal@21757 258 call _main
pascal@21757 259 ;never return
pascal@19538 260
pascal@19515 261 ;***************************************************************
pascal@21757 262
pascal@19515 263 ends _TEXT
pascal@19515 264
pascal@19515 265
pascal@19515 266 end _text_start
pascal@19515 267
pascal@19515 268 ;###### END OF FILE ############################################