In Win98me, there is a global descriptor with 1FF, and the local descriptor has BFF, and there is 5F. In the Windows 2000, the global descriptor has 7F, the local descriptor is not, and there is FF. WIN98ME GDT base address C0F71000 limit 00000FFF IDT base address 800B0000 limit 000002FFWIN2000 GDT base address 80036000 limit 000003FF IDT base address 80036400 limit 000007FF
There are 16bit programs in the NTLDR file (main functionality to get hardware parameters and the initialization of hardware, switching CPU to protection mode) and 37H output functions in the OSLoader.exe program of Win32. Osloader.exe's main function is to read Boot.ini to load the system.
The following is the case of Win98ME memory allocation GDT (global descriptor table) base address C0F71000 limit 00000FFF G = 1 4K D = 1 32bit S = 0 system segment descriptor E = 1 code segment E = 0 data segment / stack segment TSS = task Status Section A V G DL Base AddR Limit P DPL SEX RW A (Access Bit) GDT 0H L 0000 0000 0000 0000GDT 1H L FFFF B900 9B00 0000 0 0 0000B900 0FFF 1 00 1 1 0 1 1GDT 2H L FFFFFFFFFFFFFFF B900 9300 0000 0 0 0000B900 0FFF 1 00 1 0 0 1 1GDT 3H L 2069 1394 8B00 C000 0 0 0 C0001394 02069 1 00 0 1 0 1 1 <
--- Busy 80386TSSGDT 4H L 0FFF 1000 92F7 C000 0 0 0 C0F71000 00FFF 1 00 1 0 0 1 0GDT 5H L FFF 0000 9B00CF 1 1 0 000000 FFFF 1 00 0 1 1GDT 6H L FFF 1000 9300 00 C1 1 0 00000000 FFFFF 1 00 1 0 1 1GDT 7H L 07FF B800 FBFB C000 0 0 0 C0FBB800 007FF 1 11 1 1 0 1 1GDT 8H L 02FF 0400 F300 0000 0 0 00000400 002FF 1 11 1 0 0 1 1GDT 9H L fff 0000 0000 0000 0 0 00 0 0 0 0 0GDT AH L fff 0000 聽 000 0000 0 0 0 00000000 0FFF 0 00 0 0 0 0GDT BH L FFFF 0000 0000 0000 0 0 00000000 0FFF 0 00 0 0 0 0 0GDT CH L fff 0000 0000 0000 0 0 00000000 0FFFF 0 00 0 0 0 0 0GDT DH L fff 0000 8900 0000 0 0 00000000 0FFFFFFFFF 10 0 0 1GDT EH L FFFF 0000 9200 00cf 1 1 0 000000 FFFFF 1 00 1 0 0 1 0GDT FH L 0003 33FE 9300 C000 0 0 0 C00033FE 00003 1 00 1 0 1 1GDT 10H L FFFF 0000 F100 008F 1 0 0 00000000 FFFF 1 11 1 0 0 1GDT 11H L 0FFF 1000 F300 8040 0 1 0 80001000 00FFF 1 11 1 0 0 1 1GDT 12H L 1000 16F4 9A05 C040 0 1 0 C00516F4 01000 1 00 1 0 1 0GDT 13H L 1000 16E5 9A05 C040 0 1 0 C00516E5 01000 1 00 1 0 1 0GDT 14H L 0100 0522 F200 0000 0 0 00000522 00100 1 11 1 0 0 1 0GDT 15H L fff 0000 9200 0040 0 1 0 000000 0FFFF 1 00 1 0 0 1 0GDT 16H L 0FFF 3000 F200 8040 0 1 0 80003000 00FFF 1 11 1 0 0 1 0GDT 17h L 5FFF 4000 8200 8000 0 0 0 0 0 0 0 0 <
--- LDT (local descriptor table) GDT 18H L 0FFF 4000 F201 8040 0 1 0 80014000 00FFF 1 11 1 0 0 1 0GDT 19h L 0FFF 5000 F201 8040 0 1 0 80015000 00FFF 1 11 1 0 0 1 0GDT 1AH L 0FFF 6000 F201 8040 0 1 0 80016000 00FFF 1 11 1 0 0 1 0GDT 1BH L 0FFF 7000 F201 8040 0 1 0 80017000 00FFF 1 11 1 0 0 1 0GDT 1CH L 0FFF 8000 F201 8040 0 1 0 80018000 00FFF 1 11 1 0 0 1 0GDT 1DH L FFFF 0000 9B00 00cf 1 1 0 00000000 FFFF 1 00 1 1 0 1 1GDT 1EH L 000f 0000 9700 00c0 1 1 0 00000000 00 00 L 0067 8EF8 8902 FF10 0 0 1 FF028EF8 00067 1 00 0 1 0 0 1 <
--- Available 80386TSSGDT 20H L fff 0000 F100 00cf 1 1 0 000000 FFFFF 1 11 1 0 0 0 1GDT 21h L 0FFF 9000 F201 8040 0 1 0 80019000 00FFF 1 11 1 0 0 1 0GDT 22H L 0133 0B96 F30000 0 0 0 00000B96 00133 1 11 1 0 0 1 1GDT 23h L 0003 5040 F100 C000 0 0 0 C0005040 00003 1 11 1 0 0 1GDT 24H L 00FF D470 F200 0000 0 0 0000D470 000FF 1 11 1 0 0 1 0GDT 25H l 00ff B800 F200 0000 0 0 0 0000B800 000FF 1 11 1 0 0 1 0GDT 26h L 0FFF 5000 F2CC 8140 0 1 0 81CC5000 00FFF 1 11 1 0 0 1 0GDT 27h L 0FFF 5000 F2EF 8240 0 1 0 82ef5000 00FFF 1 11 1 0 0 1 0GDT 28H L 0FFF 5000 F20F 8340 0 1 0 830F5000 00FFF 1 11 1 0 0 1 0GDT 29H L 0FFF 6000 F20F 8340 0 1 0 830F6000 00FFF 1 11 1 0 0 1 0GDT 2ah L 0FFF F000 F22F 8340 0 1 0 832FF000 00FFF 1 11 1 0 0 1 0GDT 2BH L 0FFF 7000 F22F 8340 0 1 0 833F7000 00FFF 1 11 1 0 0 1 0GDT 2CH L 0FFF C000 F22F 8340 0 1 0 832FC000 00FFF 1 11 1 0 0 1 0GDT 2DH L 0FFF D000 F22F 8340 0 1 0 832FD000 00FFF 1 11 1 0 0 1 0GDT 2EH L 0FFF 9000 F22F 8340 0 1 0 832F9000 00FFF 1 11 1 0 0 1 0GDT 2FH L 0FFF A000 F22F 8340 0 1 0 832FA000 00FFF 1 11 1 0 0 1 0GDT 30H L 0FFF B000 F22F 8340 0 1 0 832FB000 00FFF 1 11 1 0 0 1 0GDT 31H L 0FFF 1000 F230 8340 0 1 0 83301000 00FFF 1 11 1 0 0 1 0GDT 32H L 0FFF E000 F22F 8340 0 1 0 832FE000 00FFF 1 11 1 0 0 1 0GDT 33H L 0FFF 4000 F2D4 8340 0 1 0 83D44000 00FFF 1 11 1 0 0 1 0GDT 34H L 0FFF 6000 F230 8340 0 1 0 83306000 00FFF 1 11 1 0 0 1 0GDT 35H L 0FFF 4000 F230 8340 0 1 0 83304000 00FFF 1 11 1 0 0 1 0GDT 36H L 0FFF 5000 F230 8340 0 1 0 83305000 00FFF 1 11 1 0 0 1 0GDT 37H L 0FFF 4000 F232 8340 0 1 0 83324000 00FFF
1 11 1 0 01 0GDT 38H L 0FFF A000 F232 8340 0 1 0 8332A000 00FFF 1 11 1 0 0 1 0GDT 39H L 0FFFBB000 F232 8340 0 1 0 8332B000 00FFF 1 11 1 0 0 1 0GDT 3ah L 0FFFFFFFFFFFFFFFFFF D000 F244 8340 0 1 0 8344d000 00FFF 1 11 1 0 0 1 0GDT 3BH L 0FFF E000 F244 8340 0 1 0 8344E000 00FFF 1 11 1 0 0 1 0GDT 3CH L FFF 0000 F300 008F 1 0 0 000000 FFFF 1 11 1 0 0 1 1GDT 3DH L 0FFF 1000 F3FA 8340 0 1 0 83FA1000 00FFF 1 11 1 0 0 1 1GDT 3EH L 0FFF 1000 F245 8340 0 1 0 83451000 00FFF 1 11 1 0 0 1 0GDT 3FH L 0FFF 2000 F245 8340 0 1 0 83452000 00FFF 1 11 1 0 0 1 0GDT 40H L 0FFF 8000 F245 8340 0 1 0 83458000 00FFF 1 11 1 0 0 1 0GDT 41H L 0FFF B000 F245 8340 0 1 0 8345B000 00FFF 1 11 1 0 0 1 0GDT 42H L 0FFF 9000 F245 8340 0 1 0 83459000 00FFF 1 11 1 0 0 1 0GDT 43H L 0FFF A000 F245 8340 0 1 0 8345A000 00FFF 1 11 1 0 0 1 0GDT 44H L 0FFF C000 F2A0 8340 0 1 0 83A0C000 00FFF 1 11 1 0 0 1 0GDT 45H L 0FFF D000 F2A0 8340 0 1 0 83A0D000 00FFF 1 11 1 0 0 1 0GDT 46H L 0FFF E000 F2A0 8340 0 1 0 83A0E000 00FFF 1 11 1 0 0 1 0GDT 47H L 0FFF 8000 F29D 8340 0 1 0 839D8000 00FFF 1 11 1 0 0 1 0GDT 48H L 0FFF 0000 F2A1 8340 0 1 0 83A10000 00FFF 1 11 1 0 0 1 0GDT 49H L 0FFF 1000 F2A1 8340 0 1 0 83A11000 00FFF 1 11 1 0 0 1 0GDT 4AH L 0FFF 2000 F2A1 8340 0 1 0 83A12000 00FFF 1 11 1 0 0 1 0GDT 4BH L 0FFF 3000 F2A1 8340 0 1 0 83A13000 00FFF 1 11 1 0 0 1 0GDT 4CH L 0FFF A000 F29D 8340 0 1 0 839DA000 00FFF 1 11 1 0 0 1 0GDT 4DH L 0FFF D000 F29D 8340 0 1 0 839DD000 00FFF 1 11 1 0 01 0GDT 4EH L 0FFF E000 F29D 8340 0 1 0 839DE000 00FFF 1 11 1 0 0 1 0GDT 4FH L 0FFF 9000 F29D 8340 0 1 0 839D9000 00FFF
1 11 1 0 0 1 0GDT 50H L 0FFF B000 F29D 8340 0 1 0 839DB000 00FFF 1 11 1 0 0 1 0GDT 51H L 0FFF C000 F29D 8340 0 1 0 839DC000 00FFF 1 11 1 0 0 1 0GDT 52H L 0FFF 3000 F29E 8340 0 1 0 839E3000 00FFF 1 11 1 0 0 1 0GDT 53H L 0FFF 4000 F29E 8340 0 1 0 839E4000 00FFF 1 11 1 0 0 1 0GDT 54H L 0FFF 2000 F29E 8340 0 1 0 839E2000 00FFF 1 11 1 0 0 1 0GDT 55H L 0FFF 5000 F29E 8340 0 1 0 839E5000 00FFF 1 11 1 0 0 1 0GDT 56H L 0FFF B000 F2A0 8340 0 1 0 83A0B000 00FFF 1 11 1 0 0 1 0GDT 57H L 0FFF F000 F2A0 8340 0 1 0 83A0F000 00FFF 1 11 1 0 0 1 0GDT 58H L 0FFF 6000 F2A1 8340 0 1 0 83A16000 00FFF 1 11 1 0 0 1 0GDT 59h L 0FFF 5000 F2D4 8340 0 1 0 83D45000 00FFF 1 11 1 0 0 1 0GDT 5ah L 0FFF B000 F2FA 8340 0 1 0 83FAB000 00FFF 1 11 1 0 0 1 0GDT 5BH L 0FFF 7000 F2F7 8340 0 1 0 83f77000 00FFF 1 11 1 0 0 1 0GDT 5CH L 0FFF 8000 F2F7 8340 0 1 0 83F78000 00FFF 1 11 1 0 0 1 0GDT 5DH L 0FFF B000 F2F7 8340 0 1 0 83F7B000 00FFF 1 11 1 0 0 1 0GDT 5EH L 0FFF C000 F2F7 8340 0 1 0 83F7C000 00FFF 1 11 1 0 0 1 0GDT 5FH L 0FFF D000 F2F7 8340 0 1 0 83F7D000 00FFF 1 11 1 0 0 1 0GDT 60H L 0FFF E000 F2F7 8340 0 1 0 83F7E000 00FFF 1 11 1 0 0 1 0GDT 61H L 0FFFFFFFFFFFFFFFF1 111 0 0 1 0GDT 62H L 0FFF 1000 F2F8 8340 0 1 0 83F81000 00FFF 1 11 1 0 0 1 0GDT 63H L 0FFF 3000 F2F8 8340 0 1 0 83F83000 00FFF 1 11 1 0 0 1 0GDT 64H L 0FFF 8000 F20A 8440 0 1 0 840A8000 00FFF 1 11 1 0 0 1 0GDT 65H L 0FFF 4000 F20A 8440 0 1 0 840A4000 00FFF 1 11 1 0 0 1 0GDT 66H L 0000 000 00 00 0000 ~ GDT 1ffh L 0000 000 0000 000 00 00 000 000B0000 Boundary 000002FF
Offset Addr Selects P DPL Type C4-C0 (COUNTS) INT 0H L 9220 0028 8E00 C000 C0009220 0028 1 00 1110 00000INT 1H L 9230 0028 8E00 C000 C0009230 0028 1 00 1110 00000INT 2H L C68C 0028 8E00 C000 C000C68C 0028 1 00 1110 00000INT 3H L 9240 0028 EE00 C000 C0009240 0028 1 11 1110 00000INT 4H L 9250 0028 EE00 C000 C0009250 0028 1 11 1110 00000INT 5H L 9260 0028 EE00 C000 C0009260 0028 1 11 1110 00000INT 6H L 9270 0028 8E00 C000 C0009270 0028 1 00 1110 00000INT 7H L 9280 0028 8E00 C000 C0009280 0028 1 00 1110 00000INT 8H L 92A8 0028 8E00 C000 C00092A8 0028 1 00 1110 00000INT 9H L 9290 0028 8E00 C000 C0009290 0028 1 00 1110 00000INT AH L 92B0 0028 8E00 C000 C00092B0 0028 1 00 1110 00000INT BH L 92C0 0028 8E00 C000 C00092C0 0028 1 00 1110 00000INT CH L 92C8 0028 8e00 C000 C00092C8 0028 1 00 1110 00000 In DH L 92D0 0028 8E00 C000 C00092D0 0028 1 00 1110 00000INT EH L 92D8 0028 8E00 C000 C00092D8 0028 1 00 1110 00000INT FH L 929C 0028 8E00 C000 C000929C 0028 1 00 1110 00000INT 10H L 0366 003B E700 0000 00000366 003B 1 11 0111 00000 to INT 30H INT 11H L C6D4 0028 8E00 C000 C000C6D4 0028 1 00 1110 00000INT 12H L C6DC 0028 8E00 C000 C000C6DC 0028 1 00 1110 00000INT 13H L 0328 003B E700 0000 00000328 003B 1 11 0111 00000 to INT 30HINT 14H L C6EC 0028 8E00 C000 C000C6EC 0028 1 00 1110 000000INT 15H L 0370 003b E700 0000 00000 Turnt to INT 30HINT 16H L C6FC 0028 8e00 C000 C000C6FC 0028 1 00
1110 00000INT 17H L C704 0028 8E00 C000 C000C704 0028 1 00 1110 00000INT 18H L C70C 0028 8E00 C000 C000C70C 0028 1 00 1110 00000INT 19H L C714 0028 8E00 C000 C000C714 0028 1 00 1110 00000INT 1AH L C71C 0028 8E00 C000 C000C71C 0028 1 00 1110 00000INT 1BH L C724 0028 8E00 C000 C000C724 0028 1 00 1110 00000INT 1CH L 032C 003B E700 0000 0000032C 003B 1 11 0111 00000 to INT 30H INT 1DH L C734 0028 8E00 C000 C000C734 0028 1 00 1110 00000INT 1EH L 0000 00A3 E700 0000 00000000 00A3 1 11 0111 00000INT 1FH L C744 0028 8E00 C000 C000C744 0028 1 00 1110 00000INT 20H L C74C 0028 8E00 C000 C000C74C 0028 1 00 1110 00000INT 21H L 84EA 014F E700 0000 000084EA 014F 1 11 0111 00000 16-bit program address: 00015CEAINT 22H L C75C 0028 8E00 C000 C000C75C 0028 1 00 1110 00000INT 23h L C764 0028 8e00 C000 C000C764 0028 1 00 1110 00000 000INT 24h L 039E 003B E700 0000 0000039E 003B 1 11 0111 00000 to INT 30HINT 25H L 03B8 003B E700 0000 000003B8 003B 1 11 0111 00000 to INT 30HINT 26H L 03BA 003B E700 0000 000003BA 003B 1 11 0111 00000 to INT 30HINT 27H L C784 0028 8E00 C000 C000C784 0028 1 00 1110 00000INT 28H L C78C 0028 8E00 C000 C000C78C 0028 1 00 1110 00000INT 29H L C794 0028 8E00 C000 C000C794 0028 1 00 1110 00000INT 2AH L 032E 003B E700 0000 0000032E 003B 1 11 0111 00000 to INT 30HINT 2BH L C7A4 0028 8E00 C000 C000C7A4 0028 1 00 1110 00000INT 2CH L C7AC 0028 8E00 C000 C000C7AC 0028 1 00 1110 000000INT 2DH L C7B4 0028 8E00 C000 C000C7B4 0028 1
00 1110 00000INT 2EH L C7BC 0028 8E00 C000 C000C7BC 0028 1 00 1110 00000INT 2FH L 7D7F 0337 E700 0000 00007D7F 0337 1 11 0111 00000 16-bit program address: 802FDD7FINT 30H L 9C6C 0028 EE00 C000 C0009C6C 0028 1 11 1110 00000INT 31H L 88E9 014F E700 0000 000088E9 014F 1 11 0111 00000 16-bit program address: 000160E9INT 32H L C7DC 0028 8E00 C000 C000C7DC 0028 1 00 1110 00000INT 33H L 0372 003B E700 0000 00000372 003B 1 11 0111 00000 to INT 30HINT 34H L C7EC 0028 8E00 C000 C000C7EC 0028 1 00 1110 00000INT 35H L C7F4 0028 8E00 C000 C000C7F4 0028 1 00 1110 00000INT 36H L C7FC 0028 8E00 C000 C000C7FC 0028 1 00 1110 00000INT 37H L C804 0028 8E00 C000 C000C804 0028 1 00 1110 00000INT 38H L C80C 0028 8E00 C000 C000C80C 0028 1 00 1110 00000INT 39H L C814 0028 8e00 C000 C000C814 0028 1 00 1110 00000INT 3AH L C81C 0028 8E00 C000 C000C81C 0028 1 00 1110 00000INT 3BH L C824 0028 8E00 C000 C000C824 0028 1 00 1110 00000INT 3CH L C82C 0028 8E00 C000 C000C82C 0028 1 00 1110 00000INT 3DH L C834 0028 8E00 C000 C000C834 0028 1 00 1110 00000INT 3EH L 9326 014F E700 0000 00009326 014F 1 11 0111 00000 16-bit program address: 00016B26INT 3FH L C844 0028 EE00 C000 C000C844 0028 1 11 1110 00000INT 40H L C84C 0028 8E00 C000 C000C84C 0028 1 00 1110 00000INT 41H L C854 0028 8E00 C000 C000C854 0028 1 00 1110 00000INT 42H L C85C 0028 EE00 C000 C000C85C 0028 1 11 1110 000000INT 43H L C864 0028 8e00 C000 C000C864 0028 1 00 1110 000000INT 44H L C86C 0028 8E00 C000 C000C86C 0028 1 00
1110 00000INT 45H L C874 0028 8E00 C000 C000C874 0028 1 00 1110 00000INT 46H L C87C 0028 8E00 C000 C000C87C 0028 1 00 1110 00000INT 47H L C884 0028 8E00 C000 C000C884 0028 1 00 1110 00000INT 48H L C88C 0028 8E00 C000 C000C88C 0028 1 00 1110 00000INT 49H L C894 0028 8E00 C000 C000C894 0028 1 00 1110 00000INT 4AH L C89C 0028 8E00 C000 C000C89C 0028 1 00 1110 00000INT 4BH L C8A4 0028 8E00 C000 C000C8A4 0028 1 00 1110 00000INT 4CH L C8AC 0028 8E00 C000 C000C8AC 0028 1 00 1110 00000INT 4DH L C8B4 0028 8E00 C000 C000C8B4 0028 1 00 1110 00000INT 4EH L C8BC 0028 8E00 C000 C000C8BC 0028 1 00 1110 00000INT 4FH L 6790 00E8 8E00 FF02 FF026790 0028 1 00 1110 00010INT 50H L 8FD0 0028 8E00 C000 C0008FD0 0028 1 00 1110 00000INT 51H L 8FE0 0028 8E00 C000 C0008FE0 0028 1 00 1110 000000INT 52H L 8FF0 0028 8E00 C000 C0008F F0 0028 1 00 1110 00000INT 53H L 9000 0028 8E00 C000 C0009000 0028 1 00 1110 00000INT 54H L 9010 0028 8E00 C000 C0009010 0028 1 00 1110 00000INT 55H L 9020 0028 8E00 C000 C0009020 0028 1 00 1110 00000INT 56H L 9030 0028 8E00 C000 C0009030 0028 1 00 1110 00000INT 57H L 9040 0028 8E00 C000 C0009040 0028 1 00 1110 00000INT 58H L 9050 0028 8E00 C000 C0009050 0028 1 00 1110 00000INT 59H L 9060 0028 8E00 C000 C0009060 0028 1 00 1110 00000INT 5AH L 9070 0028 8E00 C000 C0009070 0028 1 00 1110 000INT 5BH L 9080 0028 8e00 C000 C0009080 0028 1 00 1110 000INT 5CH L 9090 0028 8e00 C000 C0009090 0028 1
