System Menu/BS2

States taken from System Menu 257 (3.1U); they may or may not be consistent across versions. This is a mess, because the state can be examined or modified by 9 different functions; only 1 is accounted for here (BS2Tick). Most of the complication seems to come from the desire to use asynchronous calls everywhere.

There is a similar (but simpler) state machine used in SaveMii mode BS2BootIRD.

Types

State number	Action	Next state(s)
0	prints out status flags ("No Disk", "Drive Reset", "Wait Spinup", "Boot from Cache"), delay?, enable waiting-for-disk?	2, 52
1	delay	2
2	delay, enable waiting-for-disk?, DVDResetAsync	3
3	bs2_issue_dvd_command, delay, __DVDGetCoverStatusAsync, create cache.dat?	4
4	ReadDriveInfo via cache.dat or DVDInquiryAsync	5
5	wait for dvd & nand commands to finish, update cache.dat if necessary, setup 800030E6 [16bit] based on drive info and console type	8
6	DVDDownRotationAsync	7
7	wait for dvd & nand commands to finish	8
8	Read 0x20 bytes of disk id [from cache.dat or disk via DVDReadDiskID]	9
9/10	wait for dvd & nand commands to finish, update cache.dat if necessary, copy the 0x20 byte long disk id to 0x80000000. if [disk_id + 0x18] is 0x5d1c9ea3, and the [disk_id + 0] is not 'RAAE', treat as a wii disc. otherwise, if [disk_id + 0x1c] is 0xc2339f3d, treat as gamecube disk otherwise, the disk type is unknown	gamecube disk = 11, wii disk = 15, unknown = 54
11	if not waiting for a disk, exit to state 50 if waiting, disable the waiting-for-disk and check streaming [0x80000008] if streaming and no streaming buffer size defined [0x80000009], set to size 10 if streaming, setup via __DVDAudioBufferConfig go to state 12	12, 50
12	wait for dvd & nand commands to finish	13
13	async unencrypted 0x2000 byte dvd read	14
14	wait for dvd & nand commands to finish once finished, check game region	region ok = 50 region not match = 54
15	unknown check can switch to state 70 read 0x20 bytes from disk (game toc?)	16
16	wait for dvd & nand commands to finish, update cache.dat if necessary	17
17	read partition info from disk	18
18	wait for dvd & nand commands to finish, update cache.dat if necessary go through the game partition, making note of those of type 0 and 1	19
19	read 0x2000 bytes from disk	20
20	wait for dvd & nand commands to finish, update cache.dat if necessary if 0xc3f81a8e not found at the end of read block, go to state 54 if region check fails (SCGetProductGameRegion), go to state 54 if BS2IsValidDisc check fails, go to state 54 if booting from cache, go to state 37 if there's a partition of type 1, go to state 21 if there's a partition of type 0, go to state 37 otherwise, go to state 54	21,37,54
21	DVDOpenPartitionAsync opens the type 1 partition	22
22	wait for dvd & nand commands to finish and print out TMD info	23
23	use DVDReadAbsAsyncForBS to read disk header	24
24	wait for dvd & nand commands to finish check for 0x5d1c9ea3 in header (wii or gc disc)	24, 25 (non-wii/gc disc), 35 (wii/gc disc)
25	DVDReadAbsAsyncForBS [read 0x20 bytes from 0x910 (<<2?) in the partition]	26
26	wait for dvd & nand commands to finish, update cache.dat if necessary print out appLoaderLength / appLoaderFunc1	27
27	DVDReadAbsAsyncForBS [read (appLoaderLength rounded up to next 0x20 multiple) bytes from 0x918 (<<2?) in the partition to 0x81200000 ]	28
28	wait for dvd & nand commands to finish, update cache.dat if necessary ICInvalidateRange from 0x81200000 to length of apploader, rounded up to nearest 0x20 multiple call apploader init func with 3 parameters call callback1 from apploader_init	29
29	call apploader main func, returns address, length, offset print "Addr [0x%x] length [0x%x] offset [0x%x]" DVDReadAbsAsyncForBS using offset, length to load to address if check value in 0x800030D4 is set, cache some other values	30 (apploader main returned non-zero) 31 (apploader main returned zero)
30	wait for dvd & nand commands to finish, update cache.dat if necessary	29
31	__DVDFSInit BS2UpdateInit - spawn off a thread that does the __update.inf/etc stuff	32
32	BS2UpdateState if an update is in progress: BS2GetUpdateEntryNum BS2UpdateState BS2GetUpdateEntryNum BS2Report("%d entries") __DVDGetCoverStatusAsync state 33 otherwise: __DVDGetDriveStatus based on status (?), DVDCancelAllAsync	32 1 (no update) 33 (update present) 35 ("No Entry"?)
33	bs2_issue_dvd_command? BS2UpdateState __DVDGetCoverStatusAsync	33 or 34
34	BS2UpdateState __DVDGetDriveStatus based on status (?), DVDCancelAllAsync based on return code of BS2UpdateState, print "Update success", "Update success\nPlease reboot", or "Update failed"	34 35 (update success) 58 (update failed)
35	DVDClosePartitionAsync	36
36	bs2_issue_dvd_command? BS2UpdateState	37 54 65
37	Open partition from cache.dat, or DVDPartitionOpenAsync	38
38	print TMD info?	39
39	read from cache?	40
40	print appLoaderLength / appLoaderFunc1	41
41	read from cache?	42
42	call apploader init func	43
43	call apploader main func	44 or 45
44	?	43 or 44
45	check for banner; if present, open it and read it from disc	46 (banner) 47 (no banner)
46	?	47
47	DVDClosePartitionAsync	48
48	?	49 69 72
49/69/72	bs2_issue_dvd_command? __DVDGetCoverStatusAsync	49/69/72 (state changed by bs2_async_callback?)
50	bs2_issue_dvd_command __DVDGetCoverStatusAsync	50 (state changed by bs2_async_callback?)
51	deallocate something?	2
52/53	deallocate something? bs2_issue_dvd_command? __DVDGetCoverStatusAsync	52/53 (state changed by bs2_async_callback?)
54	deallocate something? DVDChangeDiskAsyncForBS	55
55/56	bs2_issue_dvd_command?	55/56 (?)
57/58	deallocate something?	57/58?
59/63	?	58 59 64
60	something with disc cache?	61
61	DVDClosePartitionAsync	62
62	something with disc cache?	63
64	?	2 3 15 57 64
65	deallocate something?	65 (?)
66	__DVDGetCoverStatusAsync	66, 67
67/68	bs2_issue_dvd_command?	67/68?
70	DVDGetPartitionParamsAsync	71
71	something with ticket? DVDOpenPartitionWithParams	38 71