ref: 4a120a381652668b7eb9313d9b8ca1835ddccb91
dir: /sys/src/9/bcm/l.s/
/* * Broadcom bcm2835 SoC, as used in Raspberry Pi * arm1176jzf-s processor (armv6) */ #include "arm.s" TEXT _start(SB), 1, $-4 /* * load physical base for SB addressing while mmu is off * keep a handy zero in R0 until first function call */ MOVW $setR12(SB), R12 SUB $KZERO, R12 ADD $PHYSDRAM, R12 MOVW $0, R0 /* * SVC mode, interrupts disabled */ MOVW $(PsrDirq|PsrDfiq|PsrMsvc), R1 MOVW R1, CPSR /* * disable the mmu and L1 caches * invalidate caches and tlb */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl BIC $(CpCdcache|CpCicache|CpCpredict|CpCmmu), R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvu), CpCACHEall MCR CpSC, 0, R0, C(CpTLB), C(CpTLBinvu), CpTLBinv ISB /* * clear mach and page tables */ MOVW $PADDR(MACHADDR), R1 MOVW $PADDR(KTZERO), R2 _ramZ: MOVW R0, (R1) ADD $4, R1 CMP R1, R2 BNE _ramZ /* * start stack at top of mach (physical addr) * set up page tables for kernel */ MOVW $PADDR(MACHADDR+MACHSIZE-4), R13 BL ,mmuinit(SB) /* * set up domain access control and page table base */ MOVW $Client, R1 MCR CpSC, 0, R1, C(CpDAC), C(0) MOVW $PADDR(L1), R1 MCR CpSC, 0, R1, C(CpTTB), C(0) /* * enable caches, mmu, and high vectors */ MRC CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl ORR $(CpChv|CpCdcache|CpCicache|CpCmmu), R0 MCR CpSC, 0, R0, C(CpCONTROL), C(0), CpMainctl ISB /* * switch SB, SP, and PC into KZERO space */ MOVW $setR12(SB), R12 MOVW $(MACHADDR+MACHSIZE-4), R13 MOVW $_startpg(SB), R15 TEXT _startpg(SB), 1, $-4 /* * enable cycle counter */ MOVW $1, R1 MCR CpSC, 0, R1, C(CpSPM), C(CpSPMperf), CpSPMctl /* * call main and loop forever if it returns */ BL ,main(SB) B ,0(PC) BL _div(SB) /* hack to load _div, etc. */ TEXT fsrget(SB), 1, $-4 /* data fault status */ MRC CpSC, 0, R0, C(CpFSR), C(0), CpFSRdata RET TEXT ifsrget(SB), 1, $-4 /* instruction fault status */ MRC CpSC, 0, R0, C(CpFSR), C(0), CpFSRinst RET TEXT farget(SB), 1, $-4 /* fault address */ MRC CpSC, 0, R0, C(CpFAR), C(0x0) RET TEXT lcycles(SB), 1, $-4 MRC CpSC, 0, R0, C(CpSPM), C(CpSPMperf), CpSPMcyc RET TEXT splhi(SB), 1, $-4 MOVW $(MACHADDR+4), R2 /* save caller pc in Mach */ MOVW R14, 0(R2) MOVW CPSR, R0 /* turn off irqs (but not fiqs) */ ORR $(PsrDirq), R0, R1 MOVW R1, CPSR RET TEXT splfhi(SB), 1, $-4 MOVW $(MACHADDR+4), R2 /* save caller pc in Mach */ MOVW R14, 0(R2) MOVW CPSR, R0 /* turn off irqs and fiqs */ ORR $(PsrDirq|PsrDfiq), R0, R1 MOVW R1, CPSR RET TEXT splflo(SB), 1, $-4 MOVW CPSR, R0 /* turn on fiqs */ BIC $(PsrDfiq), R0, R1 MOVW R1, CPSR RET TEXT spllo(SB), 1, $-4 MOVW CPSR, R0 /* turn on irqs and fiqs */ BIC $(PsrDirq|PsrDfiq), R0, R1 MOVW R1, CPSR RET TEXT splx(SB), 1, $-4 MOVW $(MACHADDR+0x04), R2 /* save caller pc in Mach */ MOVW R14, 0(R2) MOVW R0, R1 /* reset interrupt level */ MOVW CPSR, R0 MOVW R1, CPSR RET TEXT spldone(SB), 1, $0 /* end marker for devkprof.c */ RET TEXT islo(SB), 1, $-4 MOVW CPSR, R0 AND $(PsrDirq), R0 EOR $(PsrDirq), R0 RET TEXT tas(SB), $-4 TEXT _tas(SB), $-4 MOVW R0,R1 MOVW $1,R0 SWPW R0,(R1) /* fix: deprecated in armv6 */ RET TEXT setlabel(SB), 1, $-4 MOVW R13, 0(R0) /* sp */ MOVW R14, 4(R0) /* pc */ MOVW $0, R0 RET TEXT gotolabel(SB), 1, $-4 MOVW 0(R0), R13 /* sp */ MOVW 4(R0), R14 /* pc */ MOVW $1, R0 RET TEXT getcallerpc(SB), 1, $-4 MOVW 0(R13), R0 RET TEXT idlehands(SB), $-4 BARRIERS MOVW CPSR, R3 BIC $(PsrDirq|PsrDfiq), R3, R1 /* spllo */ MOVW R1, CPSR MOVW $0, R0 /* wait for interrupt */ MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEintr), CpCACHEwait ISB MOVW R3, CPSR /* splx */ RET TEXT coherence(SB), $-4 BARRIERS RET /* * invalidate tlb */ TEXT mmuinvalidate(SB), 1, $-4 MOVW $0, R0 MCR CpSC, 0, R0, C(CpTLB), C(CpTLBinvu), CpTLBinv BARRIERS RET /* * mmuinvalidateaddr(va) * invalidate tlb entry for virtual page address va, ASID 0 */ TEXT mmuinvalidateaddr(SB), 1, $-4 MCR CpSC, 0, R0, C(CpTLB), C(CpTLBinvu), CpTLBinvse BARRIERS RET /* * drain write buffer * writeback and invalidate data cache */ TEXT cachedwbinv(SB), 1, $-4 DSB MOVW $0, R0 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwbi), CpCACHEall RET /* * cachedwbinvse(va, n) * drain write buffer * writeback and invalidate data cache range [va, va+n) */ TEXT cachedwbinvse(SB), 1, $-4 MOVW R0, R1 /* DSB clears R0 */ DSB MOVW n+4(FP), R2 ADD R1, R2 SUB $1, R2 BIC $(CACHELINESZ-1), R1 BIC $(CACHELINESZ-1), R2 MCRR(CpSC, 0, 2, 1, CpCACHERANGEdwbi) RET /* * cachedwbse(va, n) * drain write buffer * writeback data cache range [va, va+n) */ TEXT cachedwbse(SB), 1, $-4 MOVW R0, R1 /* DSB clears R0 */ DSB MOVW n+4(FP), R2 ADD R1, R2 BIC $(CACHELINESZ-1), R1 BIC $(CACHELINESZ-1), R2 MCRR(CpSC, 0, 2, 1, CpCACHERANGEdwb) RET /* * drain write buffer and prefetch buffer * writeback and invalidate data cache * invalidate instruction cache */ TEXT cacheuwbinv(SB), 1, $-4 BARRIERS MOVW $0, R0 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwbi), CpCACHEall MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvi), CpCACHEall RET /* * invalidate instruction cache */ TEXT cacheiinv(SB), 1, $-4 MOVW $0, R0 MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvi), CpCACHEall RET