TODO revision 1.10 
1$NetBSD: TODO,v 1.10 2000/05/09 07:30:14 soda Exp $
2
3To do list (not in any particular order).
4
5    o	XXX sudden hang up in a few minutes or dozens of minutes.
6	2000 Mar 17 -current is OK. Mar 29 is NG.
7
8    o	Move the RO and WIRED attribute from the pte to the pv table.
9	This saves four instructions in the tlb miss handler.
10
11    o   Boot. Standalone boot program instead of booting the kernel directly?
12
13    o   Find out why bitmap load to S3-928 flashes screen. (X server)
14	Know why (enable linear mode). Need S3 info.
15
16    o   Can we have 32 double registers?
17
18    o	64bit kernel/userland
19
20    o	repair DeskStation and Algor support
21
22	-   64bit device physical address space for Tyne (see OpenBSD pmap.c)
23
24	-   requires bus_dma
25
26    o	source code structure is quite obsolete,
27	general clean up is needed as nisimura-san suggested.
28	especially:
29
30 	-   introduce struct platform and remove ugly ``switch (cputype)''
31	    in many places.
32
33	-   redesign interrupt handler framework to be flexible for
34	    possible variations; must be sane and useful for R4030/R4230
35	    'local' devices and any combinations with ISA/EISA/PCI
36
37	-   implement and use bus_dma, keeping in mind TLB assisted VDMA
38	    that R4030/R4230 chip provides
39
40	-   clean up bus_space implementation, remove inb/outb
41
42	-   try to interporate HZ; may be possible for R4030/R4230 system
43	    or 'hardclock() by R4000' system.  Clock resolution of 100Hz
44	    without any interporation is substandard
45
46    o	overblocking on interrupt handler, and related problems
47
48	-   SR_INT_IE should be enabled before calling hardclock().
49	    Since this is not done currently, spllowersoftclock()
50	    on hardclock() doesn't have effect, and softclock() is
51	    handled with all interrupt disabled in this case.
52		-> overblocking, possibly causes missing hardclock()
53
54	-   MIPS3_CLKF_BASEPRI() doesn't work correctly,
55	    when MIPS_INT_MASK_5 (== MIPS_INT_MASK_CLOCK) is disabled.
56		-> micro optimization on hardclock() doesn't work.
57		   but currently this may make hardclock() latency better
58		   due to above SR_INT_IE problem.
59	    s/MIPS_INT_MASK/MIPS3_INT_MASK/ makes this work, although tricky.
60
61	-   if (ipending & INT_MASK_REAL_DEV) == 0,
62	    softnet() and softclock() are handled with all interrupt disabled.
63		-> overblocking, possibly causes missing hardclock()
64
65	-   softclock() is handled with softnet() disabled.
66		-> slightly overblocking
67
68	-   `netisr' handling in netintr() implies potential race condition.
69	    `netisr' access should be protected by splnet().
70	    currently this is not real problem due to above overblocking.
71
72	    `ssir' handling on many mips ports has same problem.
73	    It should be protected by splnet() or splserial() or splhigh()
74	    (depends on the highest interrupt level which sets `ssir').
75	    Since `ssir' is accessed not only by setsoftnet() but also
76	    by setsoft(), setsoftnet() should protect `ssir' by splserial()
77	    or something. (i.e. priority level which setsoft() will be called)
78	    Probably, it is better to split `ssir' variable for each
79	    priority level.
80	    also, _clearsoftintr() should be called before `ssir' access.
81	    currently this is not real problem due to above overblocking.
82
83	-   INT_MASK_REAL_DEV should be removed
84
85    o	it is better to always disable MIPS_INT_MASK_CLOCK.
86	those are the points which should be fixed:
87	mips_idle: li t0, (MIPS_INT_MASK | MIPS_SR_INT_IE)
88	machdep.c: curpcb->pcb_context[11] = MIPS_INT_MASK | MIPS_SR_INT_IE;
89	spl0()
90	splnone()
91
92	-   MIPS_INT_MASK_CLOCK should be removed in someway
93
94    o	fix kernel start address
95
96    o	merge new wscons
97
98    o	parse ARC BIOS configuration information and use it
99
100    o	omit __BROKEN_CONFIG_UNIT_USAGE
101
102    o	omit __SWAP_BROKEN in <mips/types.h>
103
104    o	fix implementation of DELAY(), clean up clock implementation
105
106    o	asc.c scsi clock/NCR53CF94 handling clean up
107
108    o	if_sn.c ether address handling clean up
109
110    o	com_lbus.c clock handling clean up
111
112    o	implement NCR 53c700(?) driver for NEC RISCserver 2200
113	based on amiga siop driver?
114
115    o	audio driver
116
117    o	use MI driver
118
119	-   use MI ncr53c9x driver instead of home grown asc
120
121	-   use MI bha driver instead of home grown btl
122
123	-   make sonic driver MI, and share it with mac68k, newsmips/apbus
124
125	-   make fd driver MI, and share it with i386
126	    (contact christos about MI fd driver)
127
128	-   make pccons MI, and share it with i386,
129	    or simply eliminate pccons
130
131	-   LKM
132
133    o	ARC boot device name -> NetBSD root device conversion
134
135    o	and missing MI devices
136		ses?, lkm, vcoda, ...
137
138    o	way to specify serial console
139
140    o resolve "XXX"
141
142Lots of other things.....
143