Linux ?? Intel ???????????????????? - PowerPoint PPT Presentation

1 / 72

About This Presentation

Title:

Linux ?? Intel ????????????????????

Description:

Title: 1 Author: Administrator Last modified by: Steven C. Hsueh ( ) Created Date: 8/29/2002 5:40:13 PM Document presentation format – PowerPoint PPT presentation

Number of Views:103

Avg rating:3.0/5.0

Slides: 73

Provided by: edut1550

Category:

more less

Transcript and Presenter's Notes

Title: Linux ?? Intel ????????????????????

1
????

??? ???????

2
???????

??????????
Linux ?? Intel ????????????????????
???? Linux ????? Intel ?????,?????????????????
??????
????????????????????
???????????????????????????
????????????????

3
??? ???????

?????
??????
Linux????
??????
Linux????
????
???????
??

4
?????(1)

Intel 80x86 ??????????
3 ?????????
?????????????
?????? 4 GB ????????????????????
?????????????????????????????
???????????
????????????
?????,???????????????????

5
??????
6
?????(2)

Intel ???,??????? 2 ??
????????????????????,?????????,??????????
??????,?????
?????????????????????
??????????????????????
?????????????????????????

7
?????(3)

????????????????
???????,??????(? GDT)????????????????????????
???????????,??????????????????
????????????????????????
???????????????
???????????????,???????????????????

8
??????(1)

Intel ????????????????????
?????,Intel ???? 4G ??????????(??????????? 32 ??)
??????????????
????????????
?????
?????
?????

9
??????(2)

?????
??????????,?? 6 ?,??? cs?ss?ds?es?fs ? gs
cs ???????????????
ss ??????????????
ds ???????????????
?? 3 ????????????
cs ??????????? 2 ?CPL??(?? CPU ??????)
? CPL ??? 0,??????
? CPL ??? 3,??????
? Linux ????,?? CPL ???? 0 ? 3 ??????????????????

10
??????(3)

?????
???????? 8 ??????????????????,????????????????????
????
??? GDT(??????)? LDT(??????)?
??????????? GDT,?????????? LDT
?????,GDT ??????? gdtr ?????????? LDT ????? ldtr
???

11
???????
12
??????(4)

???????????
G ???????????
? G ????? 1 ,????? 4K ?????????? 1 ???
LIMIT?????????
CPU ???????? 0 ? 15 ???? 48 ? 51 ????? 20
????????,??? G ????????????????
?? G ????? 0,??????? 1B(???)? 1MB????????? 4KB ?
4GB
BASE???????????
CPU ????????? 16 ? 39 ???? 56 ? 63 ???? 32
??????????????
S ??
????? 0,?????????????????????????????????????

13
??????(5)

TYPE??????????????
DPL(?????)????????????
??? 0 ? 3,??? 0 ???????
D/B ??????????????
???????,??? 1 ?????????? 32 ??,???? 16 ??
P ????? 1 ????????????
? 53 ??????????,?????? 0
AVL?????????????? Linux ???????

14
??????(6)

????????????????????
??????????? 8 ???????????
??????????????????,?????????????????????????
?????????? GDT ? LDTCPU ???????????????
????????????????? GDT ? LDT ???

15
???????????
16
??????(7)

??????????
???? 13 ???????????
TI ?????????? GDT(TI? 0)?? LDT(TI? 1)?
RPL(?????)?? 2 ?????,?? CPU ???????(?? CPU
????????????)
???????? GDT ? LDT ????????????????? 13 ???????? 8

17
??????(8)

??????????????
?? TI ??,??????????? GDT ? LDT ?
????????? 8 ??? gdtr ? ldtr ?????????????
????????????????????????,?????????
????????????????????

18
????????????
19
Linux ????(1)

Linux ???????????
???????????,????????,??????
Linux ??????????????????????????????? GDT ?
Linux ?? GDT ?? gdt_table ?????,??? gdt ?????
????????????(LDT),????????????? LDT
Linux ???????,?????????????????????????????????TSS
???? LDT ???

20
Linux ????(2)

TSS ??
?????????? I/O ???????
?????????????? 0xeb
TYPE ????? 9 ? 11
????????????? TSS ??,? DPL ?? 0
Linux ?? 2.4 ?,????? TSS ?????,???????????? TSS
??????????

21
Linux????(3)

LDT ??
????? default_ldt ?,????????????
??????????????,??????? LDT ??,?????????????
default_ldt ???,???????????? 7
?????????? LDT,???????? 4096 ??????,??????? 511
??????,???????? LDT ?????????? GDT ?

22
Linux????(4)

???????,GDT ???? TSS ??? LDT ?? 2 ?????????
GDT ???????????? 12 2 NR_TASKS(NR_TASKS??????
????)
??????
TSS ? LDT ???????? GDT ?
??????
trap_init( ) ???? set_tss_desc(0 ,
init_task.tss) ??????? TSS ??????? GDT ?
???????? copy_thread( ) ???????,????? clone( ) ?
fork( ) ?????,??? set_tss_desc(nr ,
(tasknr-gttss)) ???????? TSS ??

23
Linux????(5)

CPU ?????
??????????????????
???????????? cs ??????????? RPL ????
??????????,??????????????
ss ????????????????????????,???? ss
?????????????????

24
??????(1)

????
???????????
????????????????????????
??????????????
?????????????????(????????)
??????????
???????????,???????????

25
??????(2)

???
????????????????
????????
???????,?????????
Intel ????,???? cr0 ????? PG ????????
? PG ?????(??? 0),??????????????????(???????)

26
??????(3)

??
Intel ???????????? 4KB ?????
32 ????????? 3 ???
?? 10 ???????? 10 ????????? 12 ???????
??????????,?????????????,??????,?????
????
????????? cr3 ?????
???????????????????
???????????????????,???????????
????????????????
?????? 12 ???,??????? 4096 ????

27
Intel 80x86 ?????
28
??????(4)

?????????? 10 ???,??????????? 1024 ???
?????????? 1024 1024 4096 232 ??????
???????????????,??????
????
??? 1 ?????????????
??? 0 ????????????
????
???????????,????????
?????????????,????????

29
??????(5)

????
????????
??????,????????????????????,???????
?????????????,????????
????
?????????????(??/?????)
????
?????????????????

30
??????(6)

PCD ? PWT ??
??????
PCD ?????????????????
PWT ????????????????
???????
? PCD ? PWT ??? 0 ,?????????????
??????
?????????
????? 1 ????????? 4MB ?????

31
??????(7)

????
Intel ? Pentium ???????
???????? 4KB ? 4MB
????????,????? 32 ????????????
??? 10 ??????,?? 22 ???????
????????????,??? cr4 ????? PSE ??
??????????????????
???????????????,????????????????????

32
????
33
??????(8)

??????
Intel ????????????????? 4 ???????
?? 2 ??????????
?????? 1????????
?? 0,??? CPL ?? 3 ????????
??? 3 ?????(????????)
???? 2 ?????(?????)
????????????????? 0,???????????????????????

34
??????(9)

?????
32 ?????,????????
64 ?????,???????
????? 16 KB,??? 214 ???
?????? 14 ???,?? 50 ?????????????????????????????
?????
Compaqs Alpha ???
64 ?????,???????
??????? 8KB,?????? 13 ???
??????? 43 ???,??? 21 ???????? 0
??? 30 ??????????? 10 ?????(????????????)

35
Linux ??????
36
Linux ????(1)

Linux ???????
?????????????????
??? 64 ?????
???????????????????
????????????????
???????????????
???????? 4 ???
??????????,????????????

37
Linux ????(2)

???????????????????
????????,??? cr3 ????????? TSS ???
????? TSS ?????? cr3 ?
?????????,??????????????
Linux ??? 32 ??????,?????????,?????????????????
32 ??? 64 ????????
???????????????? 1,??????????????

38
Linux????(3)

??????
Linux ??????? asm/page.h ? asm/pgtable.h
??????????????????????????????,????????,??????????
??????????????????????????????????????????
??????????????????????? 32 ???????
???? 32 ??????????????????????

39
Linux????(4)

??????????????????????
??????????
???????????,?????????????????????
??????????????,???????????????
????????,?????????????

40
Linux????(5)

????????????,?????????
????????????????????,?????????????
???????????????????????,?????????????????????,????
?????????,???????????????

41
Linux????(6)

????
??????????????
???????????????
Linux ??????????????? 0x00100000 ?
????????????? 2MB
?????? 0x00100000 ???????????
????????????
BIOS ??? 0 ??????????????
? 0x000a0000 ? 0x000fffff ???????? BIOS ????
??????????????????? 1MB ??
????????????????,Linux ????????? 1MB ???

42
????? 2MB ?????
43
??? ???????

?????
????
????
????????
???????
??

44
????

Linux ??????????? 4KB
??????????????,??????????????????????????????????
???
4KB ?????????????,?? 4KB ??????,??????????????????
???????
??????????????????

45
????(1)

????
???????????????????????????????????
??????????????????????????
?????????
count ???? 0 ?????????????????
0,?????????????????????????????

46
????(2)

list ??????????
?? flags?????????
?? next_hash ? pprev_hash ????????
page_hash_table ??????
?????????????,????????,????????????
buffer ???????????????

47
????(3)
typedef struct page struct list_head list / ???????????? / struct address_space mapping / ?????????? inode ? / struct page next_hash atomic_t count / ???????????? / unsigned long flags struct list_head lru / ???????????? / struct page pprev_hash struct buffer_head buffers mem_map_t
48
?????????(1)
49
?????????(2)
50
????(4)

??????????? mem_map ???
?????????? 64 ???, 1MB ????? 4 ?????? mem_map ??
MAP_NR ??????????????????,????? mem_map ?????
???? free_area_init() ?????????
??? 2 ???
start_mem ?????????????????
end_mem ?????????????? 1
?? i386_endbase ??????????????????????????
mem_map ????
?? PG_reserved ? PG_DMA ???,????????????? 0

51
?????
52
????(5)

men_init() ??
????? PG_reserved ???? 0,????????????????
???????????? 0x1000000 ???? PG_DMA ???? 0(? ISA
DMA ?????????? 16MB ??????)
???????????,????????num_physpages ??????
PG_reserved ??????
????????,?????????????????????????????????????????
???????????
????????????? count ???? 1,??? free_page()
??????? nr_free_pages ?????????????????

53
????(6)

?????? 4 ??????????????
__get_free_pages (gfp_mask , order)????? 2order
?????
__get_dma_pages(gfp_mask , order)???????? DMA
???,??????? __get_free_pages(gfp_mask
GFP_DMA,order) ??
__get_free_page(gfp_mask)??????,???__get_free_pag
es(gfp_mask , 0)
get_free_page(gfp_mask)???__get_free_page(gfp_mas
k),??????? 0
gfp_mask ??????????????

54
??__get_free_pages() ? gfp_mask ?????
55
????????(1)

?????????????????????????????, 2 ??????
??????????????????????
????????????????,Linux ??????
? DMA ??????????,??????????
Linux ????????????????
????????????? 10 ??????????,????? 1? 2? 4? 8? 16?
32? 64? 128? 256 ? 512 ?????
???????????????????????????

56
????????(2)

???????????
??????? 128 ?????,???????????? 128
???????????????
??????,????? 256 ????????
???,????? 128 ???????,??? 128 ????????? 128
??????
?????? 256 ?????????????,????? 512 ????????
???,???? 128 ????????,??? 384 ???,???? 256 ? 128
???,??????? 256 ????????? 128 ??????
????? 512 ?????????,????????????????

57
????????(3)

????????????,????
???? 2 ???? b ????????????????? 2b ???
????????
? 2 ??????
? 2 ????????
? 1 ???,? 1 ????????? 2 b 212 ???

58
????????(4)

Linux ?? 2 ????????
?????? ISA DMA ???
??????????
??????????????
????? men_map ??
??????? free_area_struct????? free_area,??????????
???????????
?? free_area 0 ? free_area 1
????????????????,?? 10 ???
??? free_area 0 ?????????? ISA DMA, free_area
1 ???? ISA DMA
????????????????????,??????????????(?????????)

59
??????????
60
????????(5)

free_area 0 ? free_area 1 ????????????????
free_area_struct ???
?????????????????????Linux ??? free_area_struct
??????????????,???????

struct free_area_struct struct page next struct page prev unsigned int map unsigned long count
61
????????(6)

free_area 0 ? free_area 1 ????? k ??
free_area 0/1k ??? next ? prev ???????? 2k
?????????
???????????????????????
count ??????????????????
map ???????????,?????????????
??????? 2 ??????????
????? 0,??? 2 ????????????????????? 1,??? 2 ????
1 ?????
?? 2 ?????????????,???? 2 ?????? 2 ?????

62
??? ???????