ref: 1bfde841484fadb1c41f41a6279e7e070f61a31b
dir: /sys/src/9/bcm/armv7.s/
/* * Broadcom bcm2836 SoC, as used in Raspberry Pi 2 * 4 x Cortex-A7 processor (armv7) */ #include "arm.s" #define CACHELINESZ 64 #define ICACHELINESZ 32 #undef DSB #undef DMB #undef ISB #define DSB WORD $0xf57ff04f /* data synch. barrier; last f = SY */ #define DMB WORD $0xf57ff05f /* data mem. barrier; last f = SY */ #define ISB WORD $0xf57ff06f /* instr. sync. barrier; last f = SY */ #define WFI WORD $0xe320f003 /* wait for interrupt */ #define WFI_EQ WORD $0x0320f003 /* wait for interrupt if eq */ #define ERET WORD $0xe160006e /* exception return from HYP */ #define SEV WORD $0xe320f004 /* send event */ /* tas/cas strex debugging limits; started at 10000 */ #define MAXSC 1000000 TEXT armstart(SB), 1, $-4 /* * if not cpu0, go to secondary startup */ CPUID(R1) BNE reset /* * go to SVC mode, interrupts disabled */ BL svcmode(SB) /* * disable the mmu and caches */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl BIC $(CpCdcache|CpCicache|CpCmmu), R1 ORR $(CpCsbo|CpCsw), R1 BIC $CpCsbz, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl BARRIERS /* * turn SMP off */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BIC $CpACsmp, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BARRIERS /* * clear mach and page tables */ MOVW $PADDR(MACHADDR), R1 MOVW $PADDR(KTZERO), R2 MOVW $0, R0 _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 MOVW $PADDR(L1), R0 BL mmuinit(SB) BL mmuinvalidate(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 ORR $(CpTTBs|CpTTBowba|CpTTBiwba), R1 MCR CpSC, 0, R1, C(CpTTB), C(0) MCR CpSC, 0, R1, C(CpTTB), C(0), CpTTB1 /* cortex has two */ /* * invalidate my caches before enabling */ BL cachedinv(SB) BL cacheiinv(SB) BL l2cacheuinv(SB) BARRIERS /* * turn SMP on */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl ORR $CpACsmp, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BARRIERS /* * 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 BARRIERS /* * 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<<31), R1 MCR CpSC, 0, R1, C(CpCLD), C(CpCLDena), CpCLDenacyc MOVW $1, R1 MCR CpSC, 0, R1, C(CpCLD), C(CpCLDena), CpCLDenapmnc /* * call main and loop forever if it returns */ BL ,main(SB) B ,0(PC) BL _div(SB) /* hack to load _div, etc. */ /* * startup entry for cpu(s) other than 0 */ TEXT cpureset(SB), 1, $-4 reset: /* * load physical base for SB addressing while mmu is off */ MOVW $setR12(SB), R12 SUB $KZERO, R12 ADD $PHYSDRAM, R12 /* * SVC mode, interrupts disabled */ BL svcmode(SB) /* * disable the mmu and caches */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl BIC $(CpCdcache|CpCicache|CpCmmu), R1 ORR $(CpCsbo|CpCsw), R1 BIC $CpCsbz, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpMainctl BARRIERS /* * turn SMP off */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BIC $CpACsmp, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BARRIERS /* * find Mach for this cpu */ MRC CpSC, 0, R2, C(CpID), C(CpIDidct), CpIDmpid AND $(MAXMACH-1), R2 /* mask out non-cpu-id bits */ SLL $2, R2 /* convert to word index */ MOVW $machaddr(SB), R0 BIC $KSEGM, R0 ORR $PHYSDRAM, R0 ADD R2, R0 /* R0 = &machaddr[cpuid] */ MOVW (R0), R0 /* R0 = machaddr[cpuid] */ CMP $0, R0 BEQ 0(PC) /* must not be zero */ SUB $KZERO, R0, R(MACH) /* m = PADDR(machaddr[cpuid]) */ /* * start stack at top of local Mach */ ADD $(MACHSIZE-4), R(MACH), R13 BL mmuinvalidate(SB) /* * set up domain access control and page table base */ MOVW $Client, R1 MCR CpSC, 0, R1, C(CpDAC), C(0) MOVW 12(R(MACH)), R1 /* m->mmul1 */ SUB $KZERO, R1 /* phys addr */ ORR $(CpTTBs|CpTTBowba|CpTTBiwba), R1 MCR CpSC, 0, R1, C(CpTTB), C(0) MCR CpSC, 0, R1, C(CpTTB), C(0), CpTTB1 /* cortex has two */ /* * invalidate my caches before enabling */ BL cachedinv(SB) BL cacheiinv(SB) BARRIERS /* * turn SMP on */ MRC CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl ORR $CpACsmp, R1 MCR CpSC, 0, R1, C(CpCONTROL), C(0), CpAuxctl BARRIERS /* * 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 BARRIERS /* * switch MACH, SB, SP, and PC into KZERO space */ ADD $KZERO, R(MACH) MOVW $setR12(SB), R12 ADD $KZERO, R13 MOVW $_startpg2(SB), R15 TEXT _startpg2(SB), 1, $-4 /* * enable cycle counter */ MOVW $(1<<31), R1 MCR CpSC, 0, R1, C(CpCLD), C(CpCLDena), CpCLDenacyc MOVW $1, R1 MCR CpSC, 0, R1, C(CpCLD), C(CpCLDena), CpCLDenapmnc /* * call cpustart and loop forever if it returns */ MRC CpSC, 0, R0, C(CpID), C(CpIDidct), CpIDmpid AND $(MAXMACH-1), R0 /* mask out non-cpu-id bits */ BL ,cpustart(SB) B ,0(PC) /* * get into SVC mode with interrupts disabled * raspberry pi firmware since 29 Sept 2015 starts in HYP mode */ TEXT svcmode(SB), 1, $-4 MOVW CPSR, R1 AND $PsrMask, R1 MOVW $PsrMhyp, R2 CMP R2, R1 MOVW $(PsrDirq|PsrDfiq|PsrMsvc), R1 BNE nothyp MSR(1, 1, 1, 0xe) /* MOVW R1, SPSR_HYP */ MSR(0, 14, 1, 0xe) /* MOVW R14, ELR_HYP */ ERET nothyp: MOVW R1, CPSR RET TEXT cpidget(SB), 1, $-4 /* main ID */ MRC CpSC, 0, R0, C(CpID), C(0), CpIDid RET 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 cpctget(SB), 1, $-4 /* cache type */ MRC CpSC, 0, R0, C(CpID), C(CpIDidct), CpIDct RET TEXT lcycles(SB), 1, $-4 MRC CpSC, 0, R0, C(CpCLD), C(CpCLDcyc), 0 RET TEXT splhi(SB), 1, $-4 MOVW R14, 4(R(MACH)) /* save caller pc in m->splpc */ MOVW CPSR, R0 /* turn off irqs (but not fiqs) */ ORR $(PsrDirq), R0, R1 MOVW R1, CPSR RET TEXT splfhi(SB), 1, $-4 MOVW R14, 4(R(MACH)) /* save caller pc in m->splpc */ 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 */ MOVW $0, R1 CMP.S R1, R(MACH) MOVW.NE R1, 4(R(MACH)) /* clear m->splpc */ BIC $(PsrDirq|PsrDfiq), R0, R1 MOVW R1, CPSR RET TEXT splx(SB), 1, $-4 MOVW R14, 4(R(MACH)) /* save caller pc in m->splpc */ 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 cas(SB), $0 TEXT cmpswap(SB), $0 MOVW ov+4(FP), R1 MOVW nv+8(FP), R2 spincas: LDREX (R0), R3 CMP.S R3, R1 BNE fail STREX R2, (R0), R4 CMP.S $0, R4 BNE spincas MOVW $1, R0 DMB RET fail: CLREX MOVW $0, R0 RET TEXT tas(SB), $-4 TEXT _tas(SB), $-4 /* _tas(ulong *) */ /* returns old (R0) after modifying (R0) */ MOVW R0,R5 DMB MOVW $1,R2 /* new value of (R0) */ MOVW $MAXSC, R8 tas1: LDREX (R5), R7 CMP.S $0, R7 /* old value non-zero (lock taken)? */ BNE lockbusy /* we lose */ SUB.S $1, R8 BEQ lockloop2 STREX R2,(R5),R4 CMP.S $0, R4 BNE tas1 /* strex failed? try again */ DMB B tas0 lockloop2: BL abort(SB) lockbusy: CLREX tas0: MOVW R7, R0 /* return old value */ 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 MOVW CPSR, R3 ORR $(PsrDirq|PsrDfiq), R3, R1 /* splfhi */ MOVW R1, CPSR DSB MOVW nrdy(SB), R0 CMP $0, R0 WFI_EQ DSB MOVW R3, CPSR /* splx */ RET TEXT coherence(SB), $-4 BARRIERS RET TEXT sev(SB), $-4 SEV RET /* * invalidate tlb */ TEXT mmuinvalidate(SB), 1, $-4 DSB 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 DSB MCR CpSC, 0, R0, C(CpTLB), C(CpTLBinvu), CpTLBinvse BARRIERS RET /* * `single-element' cache operations. * in arm arch v7, if effective to PoC, they operate on all cache levels, so separate * l2 functions are unnecessary. */ TEXT cachedwbse(SB), $-4 /* D writeback SE */ MOVW R0, R2 MOVW CPSR, R3 CPSID /* splhi */ BARRIERS /* force outstanding stores to cache */ MOVW R2, R0 MOVW 4(FP), R1 ADD R0, R1 /* R1 is end address */ BIC $(CACHELINESZ-1), R0 /* cache line start */ _dwbse: MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwb), CpCACHEse /* can't have a BARRIER here since it zeroes R0 */ ADD $CACHELINESZ, R0 CMP.S R0, R1 BGT _dwbse B _wait /* * TLB on armv7 loads from cache, so no need for writeback */ TEXT cachedwbtlb(SB), $-4 DSB ISB RET TEXT cachedwbinvse(SB), $-4 /* D writeback+invalidate SE */ MOVW R0, R2 MOVW CPSR, R3 CPSID /* splhi */ BARRIERS /* force outstanding stores to cache */ MOVW R2, R0 MOVW 4(FP), R1 ADD R0, R1 /* R1 is end address */ BIC $(CACHELINESZ-1), R0 /* cache line start */ _dwbinvse: MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEwbi), CpCACHEse /* can't have a BARRIER here since it zeroes R0 */ ADD $CACHELINESZ, R0 CMP.S R0, R1 BGT _dwbinvse _wait: /* drain write buffer */ BARRIERS MOVW R3, CPSR /* splx */ RET TEXT cachedinvse(SB), $-4 /* D invalidate SE */ MOVW R0, R2 MOVW CPSR, R3 CPSID /* splhi */ BARRIERS /* force outstanding stores to cache */ MOVW R2, R0 MOVW 4(FP), R1 ADD R0, R1 /* R1 is end address */ BIC $(CACHELINESZ-1), R0 /* cache line start */ _dinvse: MCR CpSC, 0, R0, C(CpCACHE), C(CpCACHEinvd), CpCACHEse /* can't have a BARRIER here since it zeroes R0 */ ADD $CACHELINESZ, R0 CMP.S R0, R1 BGT _dinvse B _wait #include "cache.v7.s"