wok-next annotate linld/stuff/src/MEMTOP.ASM @ rev 19667

linld: resync with wok
author Pascal Bellard <pascal.bellard@slitaz.org>
date Fri Mar 17 15:18:10 2017 +0100 (2017-03-17)
parents bb42796dcd3b
children 937f2ed1d5c8
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@19667 8 ifdef NO386
pascal@19667 9 p8086
pascal@19667 10 else
pascal@19515 11 p386
pascal@19667 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@19667 45 ;push cx bx
pascal@19515 46 xor cx,cx ;fix to work around buggy
pascal@19515 47 xor dx,dx ; BIOSes which dont clear/set
pascal@19515 48 stc ; carry on pass/error of
pascal@19515 49 mov ax,0E801h
pascal@19515 50 int 15h
pascal@19515 51 jc @@err
pascal@19515 52 test cx,cx ;kludge to handle BIOSes
pascal@19515 53 jnz @@use_cxdx ; which report their extended
pascal@19515 54 test dx,dx ; 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@19515 57 jmp @@end_kludge ; are more reasonable anyway...
pascal@19515 58 @@use_cxdx: xchg ax,cx
pascal@19515 59 @@end_kludge: ;now: dx=64k units above 16m
pascal@19515 60 ; ax=1k units above 1m below 16m (max 3c00h)
pascal@19667 61 ;pop bx cx
pascal@19515 62 test dx,dx
pascal@19515 63 jz tokb ;dx=0 here, ax=kbs above 1m
pascal@19515 64 xor ax,ax ;ignore info on low 16M (assume full)
pascal@19515 65 ;add dx,100h ;account for low 16M
pascal@19515 66 inc dh ;account for low 16M (optimized)
pascal@19515 67 ret
pascal@19515 68 @@err:
pascal@19515 69 ; xor ax,ax
pascal@19515 70 ; cwd
pascal@19515 71 ; ret
pascal@19515 72 ; endp _memtop_e801
pascal@19515 73
pascal@19515 74
pascal@19515 75 ;***************************************************************
pascal@19515 76 ;u32 memtop_88()
pascal@19515 77 ;***************************************************************
pascal@19515 78 ; proc _memtop_88 near
pascal@19515 79
pascal@19515 80 mov ah,88h
pascal@19515 81 int 15h ;ax=kbs above 1m
pascal@19515 82 jnc @@ok ; error: cf=1 or ax=0
pascal@19515 83 xor ax,ax ;
pascal@19515 84 @@ok:
pascal@19667 85 ; xor dx,dx
pascal@19515 86 test ax,ax ;happens on big mem systems
pascal@19515 87 jz @@fail
pascal@19515 88 tokb:
pascal@19667 89 xor dx,dx
pascal@19515 90 add ah,4h ;account for 1024 low kb
pascal@19515 91 adc dx,dx ; (optimized to death)
pascal@19515 92 ifndef NO386
pascal@19515 93 shld dx,ax,10 ;multiply by 1024
pascal@19515 94 shl ax,10 ; (kbytes -> bytes)
pascal@19515 95 else
pascal@19515 96 @@lp:
pascal@19515 97 mov cx,10
pascal@19515 98 shl ax,1 ;multiply by 1024
pascal@19515 99 rcl dx,1
pascal@19515 100 loop @@lp
pascal@19515 101 endif
pascal@19515 102 ; mov cx,ax
pascal@19515 103 ; or cx,dx ;update ZF
pascal@19515 104 ;@@fail:
pascal@19515 105 ret
pascal@19515 106 ; endp _memtop_88
pascal@19515 107
pascal@19515 108 @@fail:
pascal@19515 109
pascal@19515 110 ; proc _memtopz near
pascal@19515 111
pascal@19515 112 ; call _memtop_e801
pascal@19515 113 ; jnz @@ok
pascal@19515 114 ; call _memtop_88
pascal@19515 115 ; jnz @@ok
pascal@19515 116
pascal@19515 117 ;***************************************************************
pascal@19515 118 ;u32 memtop_cmos()
pascal@19515 119 ;***************************************************************
pascal@19515 120
pascal@19515 121 pushf
pascal@19515 122 cli
pascal@19515 123 call rdcmos17
pascal@19515 124 popf
pascal@19515 125 jmp tokb
pascal@19515 126
pascal@19515 127 rdcmos17: mov al,18h ; read bytes 17-18 from CMOS
pascal@19515 128 call @@rdcmos
pascal@19515 129 mov ah,al
pascal@19515 130 mov al,17h
pascal@19515 131 @@rdcmos: out 70h,al
pascal@19515 132 call @@ret
pascal@19515 133 in al,71h
pascal@19515 134 @@ret:
pascal@19515 135 ret
pascal@19515 136
pascal@19515 137
pascal@19515 138 ;***************************************************************
pascal@19515 139 ;u32 memtop();
pascal@19515 140 ;***************************************************************
pascal@19515 141 global _memtop:near
pascal@19515 142 _memtop:
pascal@19515 143 call _memtopz
pascal@19515 144 mov cx,40h ; min 4m
pascal@19515 145 ; If reported mem is ridiculously low, presume
pascal@19515 146 ; we had trouble detecting memory size
pascal@19515 147 cmp dx,cx
pascal@19515 148 jb @@set
pascal@19515 149 mov cx,[word _topmem+2] ; max 256m ?
pascal@19515 150 ; Kernel can have trouble with initrd at very high addr:
pascal@19515 151 ; limit mem top to 256m
pascal@19515 152 cmp dh,ch
pascal@19515 153 jb @@done
pascal@19515 154 @@set:
pascal@19515 155 xchg ax,cx
pascal@19515 156 cwd
pascal@19515 157 xchg ax,dx
pascal@19515 158 @@done:
pascal@19515 159 ; Round down to page boundary.
pascal@19515 160 ; Or else initrd's tail may end up in last, partial page.
pascal@19515 161 ; Kernel will refuse to use such initrd.
pascal@19515 162 and ax,0f000h
pascal@19515 163 ;@@ok:
pascal@19515 164 ret
pascal@19515 165
pascal@19515 166 endp _memtopz
pascal@19515 167
pascal@19515 168 ;***************************************************************
pascal@19515 169 ;void hook_int15_88();
pascal@19515 170 ;***************************************************************
pascal@19515 171 global _hook_int15_88:near
pascal@19515 172 proc _hook_int15_88 near
pascal@19515 173
pascal@19515 174 ifndef xmm_hook
pascal@19515 175 mov ax,4300h
pascal@19667 176 ifdef NO386
pascal@19667 177 cwd
pascal@19667 178 endif
pascal@19515 179 int 2fh
pascal@19667 180 cmp al,80h ; 80h = XMS driver installed
pascal@19515 181 je @@skip
pascal@19515 182 endif
pascal@19667 183 ifndef NO386
pascal@19515 184 push 0
pascal@19515 185 pop es
pascal@19515 186 mov bx,15*4
pascal@19515 187 mov eax,[bx]
pascal@19515 188 mov [saved15],eax
pascal@19515 189 else
pascal@19667 190 mov es,dx
pascal@19667 191 mov bx,15*4
pascal@19515 192 mov ax,[bx]
pascal@19515 193 mov [word saved15],ax
pascal@19515 194 mov ax,[bx+2]
pascal@19515 195 mov [word saved15+2],ax
pascal@19515 196 endif
pascal@19515 197 mov [word bx],offset int15_88
pascal@19515 198 mov [bx+2],cs
pascal@19515 199 @@skip:
pascal@19515 200 ret
pascal@19515 201 int15_88:
pascal@19515 202 cmp ah,88h
pascal@19515 203 je @@do88
pascal@19515 204 jmp [saved15]
pascal@19515 205 @@do88:
pascal@19515 206 pushf
pascal@19515 207 call [saved15]
pascal@19515 208 test ax,ax
pascal@19515 209 jnz @@iret
pascal@19515 210
pascal@19515 211 ;****** Read extended mem size (CMOS bytes 17h,18h (lo,hi))
pascal@19515 212 call rdcmos17
pascal@19515 213 @@iret:
pascal@19515 214 iret
pascal@19515 215
pascal@19515 216 endp _hook_int15_88
pascal@19515 217
pascal@19515 218 ends _TEXT
pascal@19515 219
pascal@19515 220 end
pascal@19515 221
pascal@19515 222 ;###### END OF FILE ############################################