wok annotate linld/stuff/src/MEMTOP.ASM @ rev 19883

Add openct
author Pascal Bellard <pascal.bellard@slitaz.org>
date Mon Apr 03 15:12:17 2017 +0200 (2017-04-03)
parents 2717d404353b
children 69faca221dde
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 ifdef NO386
pascal@19636 9 p8086
pascal@19636 10 else
pascal@19515 11 p386
pascal@19636 12 endif
pascal@19515 13
pascal@19515 14 group DGROUP _TEXT,_DATA,_BSS
pascal@19515 15 assume cs:DGROUP,ds:DGROUP
pascal@19515 16
pascal@19515 17
pascal@19515 18 segment _DATA byte public use16 'DATA'
pascal@19515 19
pascal@19515 20 global _topmem:dword
pascal@19515 21
pascal@19515 22 _topmem dd 10000000h ; max 256m
pascal@19515 23
pascal@19515 24 ends _DATA
pascal@19515 25
pascal@19515 26 segment _BSS byte public use16 'BSS'
pascal@19515 27
pascal@19515 28 saved15 dd ?
pascal@19515 29
pascal@19515 30 ends _BSS
pascal@19515 31
pascal@19515 32
pascal@19515 33 segment _TEXT byte public use16 'CODE'
pascal@19515 34
pascal@19515 35 ;***************************************************************
pascal@19515 36 ;u32 memtopz();
pascal@19515 37 ;***************************************************************
pascal@19515 38 global _memtopz:near
pascal@19515 39 proc _memtopz near
pascal@19515 40 ;***************************************************************
pascal@19515 41 ;u32 memtop_e801()
pascal@19515 42 ;***************************************************************
pascal@19515 43 ; proc _memtop_e801 near
pascal@19515 44
pascal@19515 45 xor cx,cx ;fix to work around buggy
pascal@19515 46 xor dx,dx ; BIOSes which dont clear/set
pascal@19515 47 stc ; carry on pass/error of
pascal@19515 48 mov ax,0E801h
pascal@19515 49 int 15h
pascal@19515 50 jc @@err
pascal@19882 51 xchg ax,cx
pascal@19882 52 push ax ;kludge to handle BIOSes
pascal@19882 53 or ax,dx ; which report their extended
pascal@19882 54 pop ax ; memory in AX/BX rather than
pascal@19515 55 jnz @@use_cxdx ; CX/DX. The spec I have read
pascal@19515 56 @@use_axbx: mov dx,bx ; seems to indicate AX/BX
pascal@19882 57 xchg ax,cx ; are more reasonable anyway...
pascal@19882 58 @@use_cxdx: ;now: dx=64k units above 16m
pascal@19515 59 ; ax=1k units above 1m below 16m (max 3c00h)
pascal@19515 60 test dx,dx
pascal@19515 61 jz tokb ;dx=0 here, ax=kbs above 1m
pascal@19515 62 xor ax,ax ;ignore info on low 16M (assume full)
pascal@19515 63 ;add dx,100h ;account for low 16M
pascal@19515 64 inc dh ;account for low 16M (optimized)
pascal@19515 65 ret
pascal@19515 66 @@err:
pascal@19515 67 ; xor ax,ax
pascal@19515 68 ; cwd
pascal@19515 69 ; ret
pascal@19515 70 ; endp _memtop_e801
pascal@19515 71
pascal@19515 72
pascal@19515 73 ;***************************************************************
pascal@19515 74 ;u32 memtop_88()
pascal@19515 75 ;***************************************************************
pascal@19515 76 ; proc _memtop_88 near
pascal@19515 77
pascal@19515 78 mov ah,88h
pascal@19515 79 int 15h ;ax=kbs above 1m
pascal@19515 80 jnc @@ok ; error: cf=1 or ax=0
pascal@19515 81 xor ax,ax ;
pascal@19515 82 @@ok:
pascal@19634 83 ; xor dx,dx
pascal@19515 84 test ax,ax ;happens on big mem systems
pascal@19879 85 jnz tokb
pascal@19879 86
pascal@19879 87 ;***************************************************************
pascal@19879 88 ;u32 memtop_cmos()
pascal@19879 89 ;***************************************************************
pascal@19879 90
pascal@19879 91 ;memtop_cmos:
pascal@19879 92 pushf
pascal@19879 93 cli
pascal@19879 94 call rdcmos17
pascal@19879 95 popf
pascal@19515 96 tokb:
pascal@19634 97 xor dx,dx
pascal@19515 98 add ah,4h ;account for 1024 low kb
pascal@19515 99 adc dx,dx ; (optimized to death)
pascal@19883 100 mov cl,10 ;multiply by 1024
pascal@19883 101 global N_LXLSH@:near
pascal@19883 102 N_LXLSH@:
pascal@19515 103 ifndef NO386
pascal@19883 104 shld dx,ax,cl
pascal@19883 105 shl ax,cl ; (kbytes -> bytes)
pascal@19515 106 else
pascal@19883 107 mov ch,0
pascal@19515 108 @@lp:
pascal@19883 109 shl ax,1
pascal@19515 110 rcl dx,1
pascal@19515 111 loop @@lp
pascal@19515 112 endif
pascal@19883 113 ret
pascal@19883 114
pascal@19515 115 ; endp _memtop_88
pascal@19515 116
pascal@19515 117 ; proc _memtopz near
pascal@19515 118
pascal@19515 119 ; call _memtop_e801
pascal@19515 120 ; jnz @@ok
pascal@19515 121 ; call _memtop_88
pascal@19515 122 ; jnz @@ok
pascal@19879 123 ; jmp memtop_cmos
pascal@19515 124
pascal@19515 125 rdcmos17: mov al,18h ; read bytes 17-18 from CMOS
pascal@19515 126 call @@rdcmos
pascal@19515 127 mov ah,al
pascal@19515 128 mov al,17h
pascal@19515 129 @@rdcmos: out 70h,al
pascal@19515 130 call @@ret
pascal@19515 131 in al,71h
pascal@19515 132 @@ret:
pascal@19515 133 ret
pascal@19515 134
pascal@19515 135
pascal@19515 136 ;***************************************************************
pascal@19515 137 ;u32 memtop();
pascal@19515 138 ;***************************************************************
pascal@19515 139 global _memtop:near
pascal@19515 140 _memtop:
pascal@19515 141 call _memtopz
pascal@19515 142 mov cx,40h ; min 4m
pascal@19515 143 ; If reported mem is ridiculously low, presume
pascal@19515 144 ; we had trouble detecting memory size
pascal@19515 145 cmp dx,cx
pascal@19515 146 jb @@set
pascal@19515 147 mov cx,[word _topmem+2] ; max 256m ?
pascal@19515 148 ; Kernel can have trouble with initrd at very high addr:
pascal@19515 149 ; limit mem top to 256m
pascal@19515 150 cmp dh,ch
pascal@19515 151 jb @@done
pascal@19515 152 @@set:
pascal@19515 153 xchg ax,cx
pascal@19515 154 cwd
pascal@19515 155 xchg ax,dx
pascal@19515 156 @@done:
pascal@19515 157 ; Round down to page boundary.
pascal@19515 158 ; Or else initrd's tail may end up in last, partial page.
pascal@19515 159 ; Kernel will refuse to use such initrd.
pascal@19515 160 and ax,0f000h
pascal@19515 161 ;@@ok:
pascal@19515 162 ret
pascal@19515 163
pascal@19515 164 endp _memtopz
pascal@19515 165
pascal@19515 166 ;***************************************************************
pascal@19515 167 ;void hook_int15_88();
pascal@19515 168 ;***************************************************************
pascal@19515 169 global _hook_int15_88:near
pascal@19515 170 proc _hook_int15_88 near
pascal@19515 171
pascal@19515 172 ifndef xmm_hook
pascal@19515 173 mov ax,4300h
pascal@19515 174 int 2fh
pascal@19571 175 cmp al,80h ; 80h = XMS driver installed
pascal@19515 176 je @@skip
pascal@19515 177 endif
pascal@19883 178 xor bx,bx
pascal@19883 179 mov es,bx
pascal@19571 180 ifndef NO386
pascal@19876 181 push cs
pascal@19876 182 push offset int15_88
pascal@19876 183 pop eax
pascal@19883 184 xchg eax,[es:bx+15*4]
pascal@19515 185 mov [saved15],eax
pascal@19515 186 else
pascal@19876 187 mov ax,offset int15_88
pascal@19883 188 xchg ax,[es:bx+15*4]
pascal@19515 189 mov [word saved15],ax
pascal@19876 190 mov ax,cs
pascal@19883 191 xchg ax,[es:bx+15*4+2]
pascal@19515 192 mov [word saved15+2],ax
pascal@19515 193 endif
pascal@19515 194 @@skip:
pascal@19515 195 ret
pascal@19515 196 int15_88:
pascal@19515 197 cmp ah,88h
pascal@19515 198 je @@do88
pascal@19876 199 @@jmp_saved15:
pascal@19515 200 jmp [saved15]
pascal@19515 201 @@do88:
pascal@19515 202 pushf
pascal@19876 203 call @@jmp_saved15
pascal@19515 204 test ax,ax
pascal@19515 205 jnz @@iret
pascal@19515 206
pascal@19515 207 ;****** Read extended mem size (CMOS bytes 17h,18h (lo,hi))
pascal@19515 208 call rdcmos17
pascal@19515 209 @@iret:
pascal@19515 210 iret
pascal@19515 211
pascal@19515 212 endp _hook_int15_88
pascal@19515 213
pascal@19515 214 ends _TEXT
pascal@19515 215
pascal@19515 216 end
pascal@19515 217
pascal@19515 218 ;###### END OF FILE ############################################