wok annotate linld/stuff/src/_BEG.ASM @ rev 21757

tazboot: spave 40k+ for zImage
author Pascal Bellard <pascal.bellard@slitaz.org>
date Mon Jun 24 16:31:09 2019 +0200 (2019-06-24)
parents f0d71e920c5a
children d8f824013cf6
rev   line source
pascal@19515 1 ;***************************************************************
pascal@19515 2 ;****** This file is distributed under GPL
pascal@19515 3 ;***************************************************************
pascal@19515 4 ideal
pascal@19515 5 %crefref
pascal@19515 6 %noincl
pascal@19515 7 %nomacs
pascal@19636 8 p8086
pascal@19515 9
pascal@19515 10 group DGROUP _TEXT,_DATA,_BSS
pascal@19515 11 assume cs:DGROUP,ds:DGROUP
pascal@19515 12
pascal@19515 13 segment _TEXT byte public use16 'CODE'
pascal@20451 14 ends _TEXT
pascal@20451 15
pascal@20451 16 segment _DATA byte public use16 'DATA'
pascal@20451 17 global _data_start:byte
pascal@20451 18 label _data_start byte
pascal@20451 19 ifndef NO386
pascal@20451 20 msg_badcpu db "I need 386+ CPU in real mode or under VCPI manager"
pascal@20451 21 endif
pascal@20451 22 global _vcpi:byte
pascal@20451 23 _vcpi db 0
pascal@20528 24 msg_badmapping db "VCPI: low 640k need 1:1 mapping",0
pascal@20451 25
pascal@20451 26 ends _DATA
pascal@20451 27
pascal@20451 28 segment _BSS byte public use16 'BSS'
pascal@21757 29
pascal@21757 30 STACK_SIZE = 1024
pascal@21757 31
pascal@20451 32 global _bss_start:byte
pascal@20451 33 label _bss_start byte
pascal@21757 34 db STACK_SIZE-2 dup(?)
pascal@21757 35 stktop dw ?
pascal@20451 36 ifdef EXTRA
pascal@20451 37 global _cpu_features:dword
pascal@20451 38 _cpu_features dd ?
pascal@20451 39 endif
pascal@20451 40 ends _BSS
pascal@20451 41
pascal@20451 42 segment _TEXT byte public use16 'CODE'
pascal@19515 43
pascal@19825 44 macro cpuid
pascal@19825 45 db 0fh,0A2h
pascal@19825 46 endm
pascal@19825 47
pascal@19515 48 org 100h
pascal@19515 49 global _text_start:byte
pascal@19515 50 label _text_start byte
pascal@19546 51
pascal@19515 52 ;***************************************************************
pascal@19515 53 ; clear bss
pascal@19515 54 ;***************************************************************
pascal@21757 55 mov sp,offset stktop
pascal@21757 56 mov si,sp
pascal@20457 57 mov bx, 0F000h ; cld ; cli & empty string
pascal@19515 58 clearbss:
pascal@20451 59 mov [si],bl ; clear bss + heap + sp
pascal@20426 60 inc si
pascal@19546 61 jne clearbss
pascal@19546 62
pascal@19546 63 ;***************************************************************
pascal@19546 64 ; check CPU
pascal@19546 65 ;***************************************************************
pascal@19546 66
pascal@19546 67 ; Check for oldies
pascal@19873 68 push bx ; < 286 : flags[12..15] are forced 1
pascal@19873 69 popf ; = 286 : flags[12..15] are forced 0
pascal@19873 70 pushf ; > 286 : only flags[15] is forced 0
pascal@19873 71 pop dx
pascal@20451 72 add dh,bh ; NS=386+, S+NC=286, S+C=86/186
pascal@20451 73 ifndef NO386
pascal@19873 74 mov bx,offset msg_badcpu
pascal@20457 75 js godie ;it is not a 386+
pascal@20451 76 else
pascal@20457 77 js endcpu86 ;it is not a 386+
pascal@19546 78 endif
pascal@19636 79 p386
pascal@19546 80 ; Check for vm
pascal@19546 81 smsw ax ;SMSW cannot be trapped! :-)
pascal@19571 82 and al,1 ;MSW_PE
pascal@19546 83 ; We're in vm
pascal@20457 84 jnz check_vcpi
pascal@20457 85
pascal@20457 86 check_rm_paging:
pascal@20457 87 ; It's a 386 in real mode, chk for paging (crazy but possible)
pascal@20457 88 mov eax,cr0
pascal@20457 89 inc eax ;CR0_PG to S
pascal@20457 90 jns endcpu386
pascal@20457 91 no_vcpi:
pascal@20457 92 p8086
pascal@20457 93 extrn die:near
pascal@20457 94 godie:
pascal@20457 95 call near die
pascal@19546 96
pascal@19546 97 ;***************************************************************
pascal@19546 98 ; checks for vcpi
pascal@19546 99 ;***************************************************************
pascal@19546 100 label check_vcpi near
pascal@20457 101 p386
pascal@19546 102 push ds
pascal@19546 103 ; Check whether it is safe to call 67h (we trust only known EMM managers)
pascal@20426 104 push si
pascal@19546 105 pop ds
pascal@19546 106 mov ds,[word 67h*4+2]
pascal@20426 107 cmp [dword si+10+4],'0XXX'
pascal@19546 108 jne skip
pascal@19825 109 ;mov eax,'XMME'
pascal@20426 110 ;xor eax,[dword si+10]
pascal@19546 111 ; QMME also works (as told by <J.S.Peatfield@damtp.cambridge.ac.uk>)
pascal@19825 112 ;shl eax,8
pascal@19825 113 mov ax,'ME'
pascal@20426 114 xor ax,[word si+10]
pascal@19546 115 skip:
pascal@19546 116 pop ds
pascal@19546 117 jne no_vcpi
pascal@19546 118
pascal@19546 119 ; Check emm manager status and version
pascal@19571 120 ;mov ah,40h ; get status
pascal@19571 121 ;int 67h
pascal@19571 122 ;test ah,ah
pascal@19571 123 ;jnz no_vcpi
pascal@19546 124 mov ah,46h ; get version
pascal@19546 125 int 67h
pascal@19546 126 test ah,ah
pascal@19546 127 jnz no_vcpi
pascal@19546 128 cmp al,40h ; version must be >= 4.0
pascal@19546 129 jb no_vcpi
pascal@19546 130 ; Check vcpi manager status
pascal@19546 131 ;;mov ax,5A01h ; ALLOCATE RAW PAGES
pascal@19546 132 ;;mov bx,4
pascal@19546 133 ;;int 67h
pascal@19546 134 ;;test ah,ah
pascal@19546 135 ;;jnz no_vcpi
pascal@19546 136 ;;push dx ;$ save handle
pascal@19546 137 mov ax,0DE00h ; check for vcpi present
pascal@19546 138 int 67h
pascal@19546 139 test ah,ah
pascal@19571 140 jnz no_vcpi
pascal@19546 141 is386vcpi:
pascal@19546 142 extrn prepare_vcpi:near
pascal@19546 143 call prepare_vcpi
pascal@19546 144 ; get_vcpi_interface() || die("VCPI: low 640k: need 1:1 mapping");
pascal@19546 145 ;extrn _get_vcpi_interface:near
pascal@19546 146 ;call _get_vcpi_interface
pascal@19546 147 mov bx,offset msg_badmapping
pascal@20457 148 jnz no_vcpi
pascal@21757 149 inc [word bx+_vcpi-msg_badmapping]
pascal@20457 150 endcpu386:
pascal@20457 151 ifdef EXTRA
pascal@20457 152 pushfd
pascal@20457 153 pop dx
pascal@20457 154 pop ax
pascal@20457 155 mov bl,al
pascal@20457 156 xor al,20h ; toggle CPUID feature bit 21
pascal@20457 157 push ax
pascal@20457 158 push dx
pascal@20457 159 popfd
pascal@20457 160 pushfd
pascal@20457 161 pop dx
pascal@20457 162 pop ax
pascal@20457 163 xor al,bl ; clear C
pascal@20457 164 je @@no_cpuid ; CPUID feature bit changed ?
pascal@20457 165 mov eax,80000001h ; Extended Processor Info and Feature Bits
pascal@20457 166 cpuid
pascal@20457 167 mov [_cpu_features],edx
pascal@20457 168 @@no_cpuid:
pascal@20457 169 endif
pascal@20457 170 endcpu86:
pascal@19636 171 p8086
pascal@19546 172
pascal@19515 173 ;***************************************************************
pascal@19515 174 ; build argv & argc
pascal@19515 175 ;***************************************************************
pascal@19546 176 extrn _heap_top:word
pascal@19546 177 mov di,[_heap_top]
pascal@19546 178 ;xor ax,ax
pascal@19546 179 ;push ax ; envp (already cleared)
pascal@19546 180 ;mov [word di],ax ; argv[0] = 0 (idem)
pascal@19515 181 mov si,80h
pascal@19515 182 lodsb
pascal@19515 183 cmp al,7Eh
pascal@19515 184 jbe alok
pascal@19515 185 mov al,7Eh
pascal@19515 186 alok:
pascal@19546 187 cbw
pascal@19515 188 xchg ax,bx
pascal@19515 189 mov [bx+si],bh ; set eos
pascal@19515 190 argbuild:
pascal@20160 191 ifdef DEBUG
pascal@20142 192 p386
pascal@20142 193 pusha
pascal@20142 194 mov bx,si
pascal@20142 195 extrn puts:near
pascal@20142 196 call puts
pascal@20142 197 popa
pascal@20160 198 endif
pascal@19515 199 mov bx,2 ; argc * 2
pascal@19515 200 argeos:
pascal@20451 201 mov cx,1 ; look for a start of string
pascal@19515 202 mov [byte si-1],bh ; mark eos
pascal@19515 203 mov ah,20h ; space will be eos
pascal@19515 204 arglp:
pascal@19515 205 lodsb
pascal@19515 206 cmp al,0h
pascal@19515 207 je argdone
pascal@19515 208 cmp al,20h
pascal@19515 209 jb argeos
pascal@19515 210 cmp al,ah
pascal@19515 211 je argeos
pascal@19515 212 cmp al,27h
pascal@19515 213 je isargstr
pascal@19515 214 cmp al,22h
pascal@19515 215 je isargstr
pascal@20451 216 jcxz arglp ; not start of string
pascal@19515 217 dec si
pascal@19884 218 ;jmp newarg
pascal@20451 219 db 0BAh ; mov dx,im opcode
pascal@19515 220 isargstr:
pascal@19515 221 mov ah,al ; expected eos
pascal@19515 222 newarg:
pascal@19515 223 mov [word bx+di],si ; argv[argc++] = si
pascal@19515 224 inc bx
pascal@19515 225 inc bx
pascal@20451 226 dec cx
pascal@19515 227 jmp arglp
pascal@19515 228 argdone:
pascal@19515 229 ;mov [word bx+di],0 ; argv[argc] = 0
pascal@19546 230 lea ax,[bx+di+2]
pascal@19546 231 mov [_heap_top],ax
pascal@19515 232 push di ; argv
pascal@19515 233 shr bx,1
pascal@19515 234 push bx ; argc
pascal@19515 235 ifndef filearg
pascal@19515 236 mov bx,[di+2] ; argv[1]
pascal@20528 237 extrn openargs:near
pascal@20528 238 call near openargs
pascal@19515 239 jc argend
pascal@19515 240 pop bx ; trash argc, argv >> 1Kb !
pascal@19546 241 global read_cmdline:near
pascal@20528 242 pop cx ; sizemax=argv
pascal@19546 243 read_cmdline:
pascal@20528 244 mov dx,di
pascal@20528 245 push dx
pascal@19515 246 push ax
pascal@20528 247 xchg ax,bx
pascal@20528 248 extrn @read$cxdxbx:near ; read(fd=bx,buffer=dx,size=cx)
pascal@20528 249 call near @read$cxdxbx
pascal@19515 250 pop bx ; fd for close
pascal@19515 251 pop si ; si=buffer=argv
pascal@19515 252 add di,ax
pascal@19515 253 extrn close:near
pascal@19515 254 call near close
pascal@19515 255 jmp argbuild
pascal@19515 256 argend:
pascal@19515 257 endif
pascal@19515 258
pascal@19515 259 ;***************************************************************
pascal@21757 260 extrn _main:near
pascal@21757 261 call _main
pascal@21757 262 ;never return
pascal@19538 263
pascal@19515 264 ;***************************************************************
pascal@21757 265
pascal@19515 266 ends _TEXT
pascal@19515 267
pascal@19515 268
pascal@19515 269 end _text_start
pascal@19515 270
pascal@19515 271 ;###### END OF FILE ############################################