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1.1 root 1: ;
2:
1.1.1.3 ! root 3: ; CPU tricks (mostly having to do with the MMU)
1.1 root 4:
5: ;
6:
1.1.1.3 ! root 7: ;
! 8:
! 9: ; set_mmu(crp,tc): called once, the first time a page table is built, to
! 10:
! 11: ; switch away from the MMU setup that came from the ROM and into the setup
! 12:
! 13: ; that we just built. The CRP is actually on the stack, and it's 8 bytes.
! 14:
! 15: ; The TC is four bytes at sp@(0xc). "Nulls" is here because we need to
! 16:
! 17: ; shove zeros into a few places.
! 18:
! 19: ;
! 20:
! 21: DATA
! 22:
! 23: nulltc: dc.l 0
! 24:
! 25:
! 26:
! 27: TEXT
! 28:
! 29: XDEF _set_mmu
! 30:
! 31: _set_mmu:
! 32:
! 33: pmove (nulltc).l,tc ; turn off mmu
! 34:
! 35: dc.l $f0390800,nulltc ; pmove nulltc,tt0
! 36:
! 37: dc.l $f0390c00,nulltc ; pmove nulltc,tt1
! 38:
! 39: pmove 4(sp),crp ; caution: crp is 8 bytes
! 40:
! 41: pmove $c(sp),tc
! 42:
! 43: rts
! 44:
! 45: ;
! 46:
! 47: ; save_mmu, restr_mmu: save and restore the MMU setup that came from ROM
! 48:
! 49: ;
! 50:
! 51: DATA
! 52:
! 53: oldcrp: dc.l 0
! 54:
! 55: dc.l 0
! 56:
! 57: oldtc: dc.l 0
! 58:
! 59: oldtt0: dc.l 0
! 60:
! 61: oldtt1: dc.l 0
! 62:
! 63:
! 64:
1.1 root 65: TEXT
66:
1.1.1.3 ! root 67: XDEF _save_mmu
! 68:
! 69: _save_mmu:
! 70:
! 71: pmove tc,oldtc
! 72:
! 73: dc.l $f0390a00,oldtt0 ; pmove tt0,oldtt0
! 74:
! 75: dc.l $f0390e00,oldtt1 ; pmove tt1,oldtt1
! 76:
! 77: pmove crp,oldcrp
! 78:
! 79: rts
! 80:
! 81:
! 82:
! 83: XDEF _restr_mmu
! 84:
! 85: _restr_mmu:
! 86:
! 87: pmove (nulltc).l,tc
! 88:
! 89: dc.l $f0390800,oldtt0 ; pmove oldtt0,tt0
! 90:
! 91: dc.l $f0390c00,oldtt1 ; pmove oldtt1,tt1
! 92:
! 93: pmove oldcrp,crp
! 94:
! 95: pmove oldtc,tc
! 96:
! 97: rts
! 98:
1.1 root 99: ;
100:
101: ; Cache tricks
102:
103: ;
104:
105: XDEF _cpush
106:
107: XREF _mcpu ; in main.c
108:
109: ;
110:
111: ; cpush(void *base, long length):
112:
113: ; flush both caches from base over a distance of length. If length is -1
114:
115: ; then the entire cache is flushed
116:
117: ;
118:
119: _cpush:
120:
121: movem.l 4(a7),d0/a0 ; get parameters
122:
123: exg a0,d0 ; and in the right order
124:
125: move.l _mcpu,d1 ; start checking the CPU type
126:
127: cmp.l #20,d1
128:
129: bcs.s noc
130:
131: cmp.l #40,d1
132:
133: bne.s is030
134:
135:
136:
137: addq.l #1,d0 ; if was -1
138:
139: beq.s abc040 ; then flush everything
140:
141: add.l #14,d0 ; round up to line boundary
142:
143: lsr.l #4,d0 ; convert to number of lines
144:
145: cmp.l #256,d0
146:
147: bcs.s fls040 ; not too many lines, so dump only some
148:
149:
150:
151: abc040: dc.w $F4F8 ; this is "cpusha bc" if your asm knows '040
152:
153: bra.s noc
154:
155:
156:
157: ; run through d0+1 times (since a0 may not be on a line boundary)
158:
159: fls040: moveq #16,d1
160:
161: do040: dc.w $F4E8 ; this is "cpushl bc,(a0)" for the '040
162:
163: add.w d1,a0
164:
165: dbf d0,do040
166:
167: bra.s noc
168:
169:
170:
171: is030:
172:
173: movec cacr,d1
174:
175: move.l d1,-(a7)
176:
177: addq.l #1,d0 ; if was -1
178:
179: beq.s abc030 ; then flush everything
180:
181: addq.l #2,d0 ; round up to long boundary
182:
183: lsr.l #2,d0 ; convert to number of longs
184:
185: cmp.l #64,d0
186:
187: bcs.s fls030 ; dump selectively
188:
189:
190:
191: abc030: or.w #$808,d1
192:
193: movec d1,cacr
194:
195: bra.s rescacr
196:
197:
198:
199: fls030: or.w #$404,d1 ; clear DC/IC entries
200:
201: ; run through d0+1 times (since a0 may not be on a long boundary)
202:
203: do030: movec a0,caar
204:
205: movec d1,cacr
206:
207: addq.w #4,a0
208:
209: dbf d0,do030
210:
211: rescacr:
212:
213: move.l (a7)+,d0
214:
215: movec d0,cacr
216:
217: noc: rts
218:
219:
220:
1.1.1.2 root 221: ;
222:
223: ; Set the stack pointer to a new value
224:
225: ; Called when we're starting GEM from the exec_os vector
226:
227:
228:
229: XDEF _setstack
230:
231: _setstack:
232:
233: move.l (sp)+,a0 ; pop return address
234:
235: move.l (sp)+,sp ; set stack pointer
236:
237: jmp (a0) ; return
238:
239:
240:
1.1.1.3 ! root 241: ;
! 242:
! 243: ; PMMU stuff
! 244:
! 245: ;
! 246:
! 247: XDEF _flush_pmmu
! 248:
! 249: _flush_pmmu:
! 250:
! 251: pflusha
! 252:
! 253: rts
! 254:
1.1 root 255: END
256:
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