source: xtideuniversalbios/trunk/Assembly_Library/Src/Util/Size.asm@ 61

Last change on this file since 61 was 41, checked in by Tomi Tilli, 14 years ago

Initial commit for Assembly Library.

File size: 3.8 KB
Line 
1; File name : Size.asm
2; Project name : Assembly Library
3; Created date : 7.9.2010
4; Last update : 15.9.2010
5; Author : Tomi Tilli
6; Description : Functions for size calculations.
7
8; Section containing code
9SECTION .text
10
11;--------------------------------------------------------------------
12; Size_GetWordSizeToAXfromBXDXAXwithMagnitudeInCX
13; Parameters:
14; BX:DX:AX: Size in magnitude
15; CX: Magnitude (0=B, 1=kiB, 2=MiB...)
16; Returns:
17; AX: Size in magnitude
18; CX: Tenths
19; DL: Magnitude character:
20; 'k' = *1024 B = kiB
21; 'M' = *1024 kiB = MiB
22; 'G' = *1024 MiB = GiB
23; 'T' = *1024 GiB = TiB
24; 'P' = *1024 TiB = PiB
25; Corrupts registers:
26; BX, DH
27;--------------------------------------------------------------------
28ALIGN JUMP_ALIGN
29Size_GetSizeToAXAndCharToDLfromBXDXAXwithMagnitudeInCX:
30 push si
31
32ALIGN JUMP_ALIGN
33.MagnitudeConversionLoop:
34 ePUSH_T si, .MagnitudeConversionLoop
35 test bx, bx ; Bits 32...47 in use?
36 jnz SHORT Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX
37 test dx, dx ; Bits 16...31 in use?
38 jnz SHORT Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX
39 cmp ax, 10000 ; 5 digits needed?
40 jae SHORT Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX
41
42 add sp, BYTE 2 ; Clean return address from stack
43 call Size_ConvertMagnitudeRemainderInSItoTenths
44 call Size_GetMagnitudeCharacterToDLfromMagnitudeInCX
45 mov cx, si
46
47 pop si
48 ret
49
50;--------------------------------------------------------------------
51; Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX
52; Parameters:
53; BX:DX:AX: Size
54; CX: Magnitude (0=B, 1=kiB, 2=MiB...)
55; Returns:
56; BX:DX:AX: Size in magnitude
57; SI: Remainder (0...1023)
58; CX: Magnitude (1=kiB, 2=MiB...)
59; Corrupts registers:
60; Nothing
61;--------------------------------------------------------------------
62ALIGN JUMP_ALIGN
63Size_DivideSizeInBXDXAXby1024andIncrementMagnitudeInCX:
64 push cx
65 xor si, si ; Zero remainder
66 mov cl, 10 ; Divide by 1024
67ALIGN JUMP_ALIGN
68.ShiftLoop:
69 call Size_DivideBXDXAXbyTwo
70 rcr si, 1 ; Update remainder
71 loop .ShiftLoop
72 eSHR_IM si, 6 ; Remainder to SI beginning
73 pop cx
74 inc cx ; Increment magnitude
75 ret
76
77
78;--------------------------------------------------------------------
79; Size_ConvertSectorCountInBXDXAXtoKiB
80; Size_DivideBXDXAXbyTwo
81; Parameters:
82; BX:DX:AX: Total sector count
83; Returns:
84; BX:DX:AX: Total size in kiB
85; CF: Remainder from division
86; Corrupts registers:
87; Nothing
88;--------------------------------------------------------------------
89ALIGN JUMP_ALIGN
90Size_ConvertSectorCountInBXDXAXtoKiB:
91Size_DivideBXDXAXbyTwo:
92 shr bx, 1 ; Divide sector count by 2...
93 rcr dx, 1 ; ...to get disk size in...
94 rcr ax, 1 ; ...kiB
95 ret
96
97
98;--------------------------------------------------------------------
99; Size_ConvertMagnitudeRemainderInSItoTenths
100; Parameters:
101; SI: Remainder from last magnitude division (0...1023)
102; Returns:
103; SI: Tenths
104; Corrupts registers:
105; DX
106;--------------------------------------------------------------------
107ALIGN JUMP_ALIGN
108Size_ConvertMagnitudeRemainderInSItoTenths:
109 push ax
110
111 mov ax, 10
112 mul si ; DX:AX = remainder * 10
113 eSHR_IM ax, 10 ; Divide AX by 1024
114 xchg si, ax ; SI = tenths
115
116 pop ax
117 ret
118
119
120;--------------------------------------------------------------------
121; Size_GetMagnitudeCharacterToDLfromMagnitudeInCX
122; Parameters:
123; CX: Magnitude (0=B, 1=kiB, 2=MiB...)
124; Returns:
125; DL: Magnitude character
126; Corrupts registers:
127; BX
128;--------------------------------------------------------------------
129ALIGN JUMP_ALIGN
130Size_GetMagnitudeCharacterToDLfromMagnitudeInCX:
131 mov bx, cx
132 mov dl, [cs:bx+.rgbMagnitudeToChar]
133 ret
134ALIGN WORD_ALIGN
135.rgbMagnitudeToChar: db " kMGTP"
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