?????????????дOS????????OS ?к???????????????????????????????????????????д??????? OS???????? GNU GRUB ?? LILO??????????????????????????? PC ?????????????е????????????????????????????????????????????MS-DOS?????????? MS-DOS ??????????????????????? ????IO.SYS????????3???????????????????????
????BIOS ??????? IBM PC compatible??IBM PC???????  ???????512????????????????0x07C00??λ??????????????????? ???????????2????????????0xAA55?? ?????????“???????”?? ????????????????????????????510????????
????MS-DOS????????????FAT???????? ?????????????????????8???? OEM??????????51???????????y??????BIOS????????????? ???3???????????????????????????漲???????? ??????????????448???????????д???????????DOS???????????????????????￡??????????????????????????????????????????????????е????????C????????Щ??

????
???MS-DOS ?????????е???????????????1??? ??飩

????BIOS???????????????????????????????????????????￡?
LengthName
2Bytes per sector
1Sectors per cluster
2Number of reserved sectors
1Number of file allocation tables
2Number of root entries
2Number of sectors (if < 65 536)
1Media descriptor
2Sectors per file allocation table
2Sectors per track
2Number of heads
4Number of hidden sectors
4Number of sectors (if ≥ 65 536)
1Disk drive index
1Reserved
1Volume signature
4Volume ID
11Volume label
8Volume type
????????????????????????CPU?????????????ζ?????????????16λ????????????1MiB??????Χ?? ?640 KiB ???????????????????μ?384KiB???????????????????????????????????????????????????????
???????????????????????????1024???????????ж???????? ????256??????????BIOS????? ?????????????????????512B?? [0x07C00?? 0x07E00)??????????????????[0×00500?? 0x07C00) ??29.75KiB ???? [0x07E00?? 0×80000) ??480.5KiB?? ?????????????? 510.25KiB????[0×80000?? 0xA0000)?л???128KiB???У? ?????Щ???????????????BIOS??????????á?
?????????????????????????У??????[0x07E00?? 0x07E05) 5B?????????е????????????????IO.SYS??????????? ????? [0×00500?? 0x07C00) 29.75B?????????????? ????????????????32B?? ????ζ?? IO.SYS ??????????952????????е????????MS-DOS 4.0 ???IO.SYS?root???е??????????. ?±????????????????
Length  Name
8   Filename
3   Extension
1   Attributes
1   Reserved
1   Creation time?? microseconds part
2   Creation time
2   Creation date
2   Last access date
2   Reserved
2   Last modified time
2   Last modified date
2   Cluster offset
4   File size in bytes
??????????16λ??С???little-endian??????YYYYYYYMMMMDDDDD???????洢?? ??????16λ??С???little-endian??????????HHHHHMMMMMMSSSSS???????洢??
???????IO.SYS?? ????3???????????? 0×00700??????????? ???????3?????????????????????????[0×00500?? 0×00700)  ???????512???????????????IO.SYS??????????????????????
????????????????????????????16-bit opcodes???????????????????? ?????????????????GCC ??binutils????????С????????????????. ?????????C?????м???.code16gcc???????????? ???????????????????????????? ?????????????????????????????????Σ???????????Σ??????????????????????????????????????????
?????????????????????п???????????
????LICENSE
????boot.c
????boot.ld
????Makefile
????????????? Google Code????? MIT Э?顣