ref: b0377e84cf31c48afed765c433abe7eebb4135a5
dir: /sys/src/9/ppc/lblast.h/
/* * on return from this function we will be running in virtual mode. * We set up the Block Address Translation (BAT) registers thus: * 1) first 3 BATs are 256M blocks, starting from KZERO->0 * 2) remaining BAT maps last 256M directly */ TEXT mmuinit0(SB), $0 /* reset all the tlbs */ MOVW $64, R3 MOVW R3, CTR MOVW $0, R4 tlbloop: TLBIE R4 SYNC ADD $BIT(19), R4 BDNZ tlbloop TLBSYNC /* BATs 0 and 1 cover memory from 0x00000000 to 0x20000000 */ /* KZERO -> 0, IBAT and DBAT, 256 MB */ MOVW $(KZERO|(0x7ff<<2)|2), R3 MOVW $(PTEVALID|PTEWRITE), R4 /* PTEVALID => Cache coherency on */ MOVW R3, SPR(IBATU(0)) MOVW R4, SPR(IBATL(0)) MOVW R3, SPR(DBATU(0)) MOVW R4, SPR(DBATL(0)) /* KZERO+256M -> 256M, IBAT and DBAT, 256 MB */ ADD $(1<<28), R3 ADD $(1<<28), R4 MOVW R3, SPR(IBATU(1)) MOVW R4, SPR(IBATL(1)) MOVW R3, SPR(DBATU(1)) MOVW R4, SPR(DBATL(1)) /* FPGABASE -> FPGABASE, DBAT, 16 MB */ MOVW $(FPGABASE|(0x7f<<2)|2), R3 MOVW $(FPGABASE|PTEWRITE|PTEUNCACHED), R4 /* FPGA memory, don't cache */ MOVW R3, SPR(DBATU(2)) MOVW R4, SPR(DBATL(2)) /* IBAT 2 unused */ MOVW R0, SPR(IBATU(2)) MOVW R0, SPR(IBATL(2)) /* direct map last block, uncached, (not guarded, doesn't work for BAT), DBAT only */ MOVW $(INTMEM|(0x7ff<<2)|2), R3 MOVW $(INTMEM|PTEWRITE|PTEUNCACHED), R4 /* Don't set PTEVALID here */ MOVW R3, SPR(DBATU(3)) MOVW R4, SPR(DBATL(3)) /* IBAT 3 unused */ MOVW R0, SPR(IBATU(3)) MOVW R0, SPR(IBATL(3)) /* enable MMU */ MOVW LR, R3 OR $KZERO, R3 MOVW R3, SPR(SRR0) /* Stored PC for RFI instruction */ MOVW MSR, R4 OR $(MSR_IR|MSR_DR|MSR_RI|MSR_FP), R4 MOVW R4, SPR(SRR1) RFI /* resume in kernel mode in caller */ RETURN