xref: /plan9-contrib/sys/src/9/ppc/lblast.h (revision 458db83292ea45506704800dedf36a95598fc2ec)
1 /*
2  * on return from this function we will be running in virtual mode.
3  * We set up the Block Address Translation (BAT) registers thus:
4  * 1) first 3 BATs are 256M blocks, starting from KZERO->0
5  * 2) remaining BAT maps last 256M directly
6  */
7 TEXT	mmuinit0(SB), $0
8 	/* reset all the tlbs */
9 	MOVW	$64, R3
10 	MOVW	R3, CTR
11 	MOVW	$0, R4
12 tlbloop:
13 	TLBIE	R4
14 	SYNC
15 	ADD		$BIT(19), R4
16 	BDNZ	tlbloop
17 	TLBSYNC
18 
19 	/* BATs 0 and 1 cover memory from 0x00000000 to 0x20000000 */
20 
21 	/* KZERO -> 0, IBAT and DBAT, 256 MB */
22 	MOVW	$(KZERO|(0x7ff<<2)|2), R3
23 	MOVW	$(PTEVALID|PTEWRITE), R4	/* PTEVALID => Cache coherency on */
24 	MOVW	R3, SPR(IBATU(0))
25 	MOVW	R4, SPR(IBATL(0))
26 	MOVW	R3, SPR(DBATU(0))
27 	MOVW	R4, SPR(DBATL(0))
28 
29 	/* KZERO+256M -> 256M, IBAT and DBAT, 256 MB */
30 	ADD		$(1<<28), R3
31 	ADD		$(1<<28), R4
32 	MOVW	R3, SPR(IBATU(1))
33 	MOVW	R4, SPR(IBATL(1))
34 	MOVW	R3, SPR(DBATU(1))
35 	MOVW	R4, SPR(DBATL(1))
36 
37 	/* FPGABASE -> FPGABASE, DBAT, 16 MB */
38 	MOVW	$(FPGABASE|(0x7f<<2)|2), R3
39 	MOVW	$(FPGABASE|PTEWRITE|PTEUNCACHED), R4	/* FPGA memory, don't cache */
40 	MOVW	R3, SPR(DBATU(2))
41 	MOVW	R4, SPR(DBATL(2))
42 
43 	/* IBAT 2 unused */
44 	MOVW	R0, SPR(IBATU(2))
45 	MOVW	R0, SPR(IBATL(2))
46 
47 	/* direct map last block, uncached, (not guarded, doesn't work for BAT), DBAT only */
48 	MOVW	$(INTMEM|(0x7ff<<2)|2), R3
49 	MOVW	$(INTMEM|PTEWRITE|PTEUNCACHED), R4	/* Don't set PTEVALID here */
50 	MOVW	R3, SPR(DBATU(3))
51 	MOVW	R4, SPR(DBATL(3))
52 
53 	/* IBAT 3 unused */
54 	MOVW	R0, SPR(IBATU(3))
55 	MOVW	R0, SPR(IBATL(3))
56 
57 	/* enable MMU */
58 	MOVW	LR, R3
59 	OR		$KZERO, R3
60 	MOVW	R3, SPR(SRR0)	/* Stored PC for RFI instruction */
61 	MOVW	MSR, R4
62 	OR		$(MSR_IR|MSR_DR|MSR_RI|MSR_FP), R4
63 	MOVW	R4, SPR(SRR1)
64 	RFI		/* resume in kernel mode in caller */
65 
66 	RETURN
67