ref: f79ba91129f15c3804a4e836cbfb822608a1059b
dir: /sys/src/boot/bitsy/il.s/
#include "mem.h" /* * Entered here from Compaq's bootldr. First relocate to * the location we're linked for and then copy back the * decompressed kernel. * * All */ TEXT _start(SB), $-4 MOVW $setR12(SB), R12 /* load the SB */ MOVW $1, R0 /* dance to make 5l think that the magic */ MOVW $1, R1 /* numbers in WORDs below are being used */ CMP.S R0, R1 /* and to align them to where bootldr wants */ BEQ _start2 WORD $0x016f2818 /* magic number to say we are a kernel */ WORD $0xc0008000 /* entry point address */ WORD $0 /* size?, or end of data? */ _start2: /* SVC mode, interrupts disabled */ MOVW $(PsrDirq|PsrDfiq|PsrMsvc), R1 MOVW R1, CPSR /* disable the MMU */ MOVW $0x130, R1 MCR CpMMU, 0, R1, C(CpControl), C(0x0) /* enable caches */ MRC CpMMU, 0, R0, C(CpControl), C(0x0) ORR $(CpCdcache|CpCicache|CpCwb), R0 MCR CpMMU, 0, R0, C(CpControl), C(0x0) /* flush caches */ MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x7), 0 /* drain prefetch */ MOVW R0,R0 MOVW R0,R0 MOVW R0,R0 MOVW R0,R0 /* drain write buffer */ MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4 /* relocate to where we expect to be */ MOVW $(512*1024),R3 MOVW $0xC0008000,R1 MOVW $0xC0200000,R2 ADD R1,R3 _relloop: MOVW (R1),R0 MOVW R0,(R2) ADD $4,R1 ADD $4,R2 CMP.S R1,R3 BNE _relloop MOVW $(MACHADDR+BY2PG), R13 /* stack */ SUB $4, R13 /* link */ /* jump to where we've been relocated */ MOVW $_relocated(SB),R15 TEXT _relocated(SB),$-4 BL main(SB) BL exit(SB) /* we shouldn't get here */ _mainloop: B _mainloop BL _div(SB) /* hack to get _div etc loaded */ TEXT mypc(SB),$-4 MOVW R14,R0 RET TEXT draincache(SB),$-4 /* write back any dirty data */ MOVW $0xe0000000,R0 ADD $(8*1024),R0,R1 _cfloop: MOVW.P 32(R0),R2 CMP.S R0,R1 BNE _cfloop /* drain write buffer and invalidate i&d cache contents */ MCR CpMMU, 0, R0, C(CpCacheFlush), C(0xa), 4 MCR CpMMU, 0, R0, C(CpCacheFlush), C(0x7), 0 /* drain prefetch */ MOVW R0,R0 MOVW R0,R0 MOVW R0,R0 MOVW R0,R0 /* disable caches */ MRC CpMMU, 0, R0, C(CpControl), C(0x0) BIC $(CpCdcache|CpCicache|CpCwb), R0 MCR CpMMU, 0, R0, C(CpControl), C(0x0) RET