ref: 83246e296ea433b65b9d295b5e08fedd39ff1ab7
dir: /utils/8a/l.s/
/* * Memory and machine-specific definitions. Used in C and assembler. */ /* * Sizes */ #define BI2BY 8 /* bits per byte */ #define BI2WD 32 /* bits per word */ #define BY2WD 4 /* bytes per word */ #define BY2PG 4096 /* bytes per page */ #define WD2PG (BY2PG/BY2WD) /* words per page */ #define PGSHIFT 12 /* log(BY2PG) */ #define PGROUND(s) (((s)+(BY2PG-1))&~(BY2PG-1)) #define MAXMACH 1 /* max # cpus system can run */ /* * Time */ #define HZ (20) /* clock frequency */ #define MS2HZ (1000/HZ) /* millisec per clock tick */ #define TK2SEC(t) ((t)/HZ) /* ticks to seconds */ #define TK2MS(t) ((((ulong)(t))*1000)/HZ) /* ticks to milliseconds */ #define MS2TK(t) ((((ulong)(t))*HZ)/1000) /* milliseconds to ticks */ /* * Fundamental addresses */ /* * Address spaces * * User is at 0-2GB * Kernel is at 2GB-4GB * * To avoid an extra page map, both the user stack (USTKTOP) and * the temporary user stack (TSTKTOP) should be in the the same * 4 meg. */ #define UZERO 0 /* base of user address space */ #define UTZERO (UZERO+BY2PG) /* first address in user text */ #define KZERO 0x80000000 /* base of kernel address space */ #define KTZERO KZERO /* first address in kernel text */ #define USERADDR 0xC0000000 /* struct User */ #define UREGADDR (USERADDR+BY2PG-4*19) #define TSTKTOP USERADDR /* end of new stack in sysexec */ #define TSTKSIZ 10 #define USTKTOP (TSTKTOP-TSTKSIZ*BY2PG) /* byte just beyond user stack */ #define USTKSIZE (16*1024*1024 - TSTKSIZ*BY2PG) /* size of user stack */ #define ROMBIOS (KZERO|0xF0000) #define MACHSIZE 4096 #define isphys(x) (((ulong)x)&KZERO) /* * known 80386 segments (in GDT) and their selectors */ #define NULLSEG 0 /* null segment */ #define KDSEG 1 /* kernel data/stack */ #define KESEG 2 /* kernel executable */ #define UDSEG 3 /* user data/stack */ #define UESEG 4 /* user executable */ #define TSSSEG 5 /* task segment */ #define SELGDT (0<<3) /* selector is in gdt */ #define SELLDT (1<<3) /* selector is in ldt */ #define SELECTOR(i, t, p) (((i)<<3) | (t) | (p)) #define NULLSEL SELECTOR(NULLSEG, SELGDT, 0) #define KESEL SELECTOR(KESEG, SELGDT, 0) #define KDSEL SELECTOR(KDSEG, SELGDT, 0) #define UESEL SELECTOR(UESEG, SELGDT, 3) #define UDSEL SELECTOR(UDSEG, SELGDT, 3) #define TSSSEL SELECTOR(TSSSEG, SELGDT, 0) /* * fields in segment descriptors */ #define SEGDATA (0x10<<8) /* data/stack segment */ #define SEGEXEC (0x18<<8) /* executable segment */ #define SEGTSS (0x9<<8) /* TSS segment */ #define SEGCG (0x0C<<8) /* call gate */ #define SEGIG (0x0E<<8) /* interrupt gate */ #define SEGTG (0x0F<<8) /* task gate */ #define SEGTYPE (0x1F<<8) #define SEGP (1<<15) /* segment present */ #define SEGPL(x) ((x)<<13) /* priority level */ #define SEGB (1<<22) /* granularity 1==4k (for expand-down) */ #define SEGG (1<<23) /* granularity 1==4k (for other) */ #define SEGE (1<<10) /* expand down */ #define SEGW (1<<9) /* writable (for data/stack) */ #define SEGR (1<<9) /* readable (for code) */ #define SEGD (1<<22) /* default 1==32bit (for code) */ /* * virtual MMU */ #define PTEMAPMEM (1024*1024) /* ??? */ #define SEGMAPSIZE 16 /* ??? */ #define PTEPERTAB (PTEMAPMEM/BY2PG) /* ??? */ #define PPN(x) ((x)&~(BY2PG-1)) /* * physical MMU */ #define PTEVALID (1<<0) #define PTEUNCACHED 0 /* everything is uncached */ #define PTEWRITE (1<<1) #define PTERONLY (0<<1) #define PTEKERNEL (0<<2) #define PTEUSER (1<<2) /* * flag register bits that we care about */ #define IFLAG 0x200 #define OP16 BYTE $0x66 /* * about to walk all over ms/dos - turn off interrupts */ TEXT origin(SB),$0 CLI #ifdef BOOT /* * This part of l.s is used only in the boot kernel. * It assumes that we are in real address mode, i.e., * that we look like an 8086. */ /* * relocate everything to a half meg and jump there * - looks wierd because it is being assembled by a 32 bit * assembler for a 16 bit world */ MOVL $0,BX INCL BX SHLL $15,BX MOVL BX,CX MOVW BX,ES MOVL $0,SI MOVL SI,DI CLD; REP; MOVSL /* JMPFAR 0X8000:$lowcore(SB) /**/ BYTE $0xEA WORD $lowcore(SB) WORD $0X8000 TEXT lowcore(SB),$0 /* * now that we're in low core, update the DS */ MOVW BX,DS /* * goto protected mode */ /* MOVL tgdtptr(SB),GDTR /**/ BYTE $0x0f BYTE $0x01 BYTE $0x16 WORD $tgdtptr(SB) MOVL CR0,AX ORL $1,AX MOVL AX,CR0 /* * clear prefetch queue (wierd code to avoid optimizations) */ CLC JCC flush MOVL AX,AX flush: /* * set all segs */ /* MOVW $SELECTOR(1, SELGDT, 0),AX /**/ BYTE $0xc7 BYTE $0xc0 WORD $SELECTOR(1, SELGDT, 0) MOVW AX,DS MOVW AX,SS MOVW AX,ES MOVW AX,FS MOVW AX,GS /* JMPFAR SELECTOR(2, SELGDT, 0):$mode32bit(SB) /**/ BYTE $0x66 BYTE $0xEA LONG $mode32bit-KZERO(SB) WORD $SELECTOR(2, SELGDT, 0) TEXT mode32bit(SB),$0 #endif BOOT /* * Clear BSS */ LEAL edata-KZERO(SB),SI MOVL SI,DI ADDL $4,DI MOVL $0,AX MOVL AX,(SI) LEAL end-KZERO(SB),CX SUBL DI,CX SHRL $2,CX CLD; REP; MOVSL /* * make a bottom level page table page that maps the first * 16 meg of physical memory */ LEAL tpt-KZERO(SB),AX /* get phys addr of temporary page table */ ADDL $(BY2PG-1),AX /* must be page aligned */ ANDL $(~(BY2PG-1)),AX /* ... */ MOVL $(4*1024),CX /* pte's per page */ MOVL $((((4*1024)-1)<<PGSHIFT)|PTEVALID|PTEKERNEL|PTEWRITE),BX setpte: MOVL BX,-4(AX)(CX*4) SUBL $(1<<PGSHIFT),BX LOOP setpte /* * make a top level page table page that maps the first * 16 meg of memory to 0 thru 16meg and to KZERO thru KZERO+16meg */ MOVL AX,BX ADDL $(4*BY2PG),AX ADDL $(PTEVALID|PTEKERNEL|PTEWRITE),BX MOVL BX,0(AX) MOVL BX,((((KZERO>>1)&0x7FFFFFFF)>>(2*PGSHIFT-1-4))+0)(AX) ADDL $BY2PG,BX MOVL BX,4(AX) MOVL BX,((((KZERO>>1)&0x7FFFFFFF)>>(2*PGSHIFT-1-4))+4)(AX) ADDL $BY2PG,BX MOVL BX,8(AX) MOVL BX,((((KZERO>>1)&0x7FFFFFFF)>>(2*PGSHIFT-1-4))+8)(AX) ADDL $BY2PG,BX MOVL BX,12(AX) MOVL BX,((((KZERO>>1)&0x7FFFFFFF)>>(2*PGSHIFT-1-4))+12)(AX) /* * point processor to top level page & turn on paging */ MOVL AX,CR3 MOVL CR0,AX ORL $0X80000000,AX ANDL $~(0x8|0x2),AX /* TS=0, MP=0 */ MOVL AX,CR0 /* * use a jump to an absolute location to get the PC into * KZERO. */ LEAL tokzero(SB),AX JMP* AX TEXT tokzero(SB),$0 /* * stack and mach */ MOVL $mach0(SB),SP MOVL SP,m(SB) MOVL $0,0(SP) ADDL $(MACHSIZE-4),SP /* start stack under machine struct */ MOVL $0, u(SB) /* * clear flags */ MOVL $0,AX PUSHL AX POPFL CALL main(SB) loop: JMP loop GLOBL mach0+0(SB), $MACHSIZE GLOBL u(SB), $4 GLOBL m(SB), $4 GLOBL tpt(SB), $(BY2PG*6) /* * gdt to get us to 32-bit/segmented/unpaged mode */ TEXT tgdt(SB),$0 /* null descriptor */ LONG $0 LONG $0 /* data segment descriptor for 4 gigabytes (PL 0) */ LONG $(0xFFFF) LONG $(SEGG|SEGB|(0xF<<16)|SEGP|SEGPL(0)|SEGDATA|SEGW) /* exec segment descriptor for 4 gigabytes (PL 0) */ LONG $(0xFFFF) LONG $(SEGG|SEGD|(0xF<<16)|SEGP|SEGPL(0)|SEGEXEC|SEGR) /* * pointer to initial gdt */ TEXT tgdtptr(SB),$0 WORD $(3*8) LONG $tgdt-KZERO(SB) /* * input a byte */ TEXT inb(SB),$0 MOVL p+0(FP),DX XORL AX,AX INB RET /* * output a byte */ TEXT outb(SB),$0 MOVL p+0(FP),DX MOVL b+4(FP),AX OUTB RET /* * input a string of shorts from a port */ TEXT inss(SB),$0 MOVL p+0(FP),DX MOVL a+4(FP),DI MOVL c+8(FP),CX CLD; REP; OP16; INSL RET /* * output a string of shorts to a port */ TEXT outss(SB),$0 MOVL p+0(FP),DX MOVL a+4(FP),SI MOVL c+8(FP),CX CLD; REP; OP16; OUTSL RET /* * test and set */ TEXT tas(SB),$0 MOVL $0xdeadead,AX MOVL l+0(FP),BX XCHGL AX,(BX) RET /* * routines to load/read various system registers */ GLOBL idtptr(SB),$6 TEXT putidt(SB),$0 /* interrupt descriptor table */ MOVL t+0(FP),AX MOVL AX,idtptr+2(SB) MOVL l+4(FP),AX MOVW AX,idtptr(SB) MOVL idtptr(SB),IDTR RET GLOBL gdtptr(SB),$6 TEXT putgdt(SB),$0 /* global descriptor table */ MOVL t+0(FP),AX MOVL AX,gdtptr+2(SB) MOVL l+4(FP),AX MOVW AX,gdtptr(SB) MOVL gdtptr(SB),GDTR RET TEXT putcr3(SB),$0 /* top level page table pointer */ MOVL t+0(FP),AX MOVL AX,CR3 RET TEXT puttr(SB),$0 /* task register */ MOVL t+0(FP),AX MOVW AX,TASK RET TEXT getcr0(SB),$0 /* coprocessor bits */ MOVL CR0,AX RET TEXT getcr2(SB),$0 /* fault address */ MOVL CR2,AX RET #define FPOFF\ WAIT;\ MOVL CR0,AX;\ ORL $0x4,AX /* EM=1 */;\ MOVL AX,CR0 #define FPON\ MOVL CR0,AX;\ ANDL $~0x4,AX /* EM=0 */;\ MOVL AX,CR0 TEXT fpoff(SB),$0 /* turn off floating point */ FPOFF RET TEXT fpinit(SB),$0 /* turn on & init the floating point */ FPON FINIT WAIT PUSHW $0x0330 FLDCW 0(SP) /* ignore underflow/precision, signal others */ POPW AX WAIT RET TEXT fpsave(SB),$0 /* save floating point state and turn off */ MOVL p+0(FP),AX WAIT FSAVE 0(AX) FPOFF RET TEXT fprestore(SB),$0 /* turn on floating point and restore regs */ FPON MOVL p+0(FP),AX FRSTOR 0(AX) WAIT RET TEXT fpstatus(SB),$0 /* get floating point status */ FSTSW AX RET /* * special traps */ TEXT intr0(SB),$0 PUSHL $0 PUSHL $0 JMP intrcommon TEXT intr1(SB),$0 PUSHL $0 PUSHL $1 JMP intrcommon TEXT intr2(SB),$0 PUSHL $0 PUSHL $2 JMP intrcommon TEXT intr3(SB),$0 PUSHL $0 PUSHL $3 JMP intrcommon TEXT intr4(SB),$0 PUSHL $0 PUSHL $4 JMP intrcommon TEXT intr5(SB),$0 PUSHL $0 PUSHL $5 JMP intrcommon TEXT intr6(SB),$0 PUSHL $0 PUSHL $6 JMP intrcommon TEXT intr7(SB),$0 PUSHL $0 PUSHL $7 JMP intrcommon TEXT intr8(SB),$0 PUSHL $8 JMP intrscommon TEXT intr9(SB),$0 PUSHL $0 PUSHL $9 JMP intrcommon TEXT intr10(SB),$0 PUSHL $10 JMP intrscommon TEXT intr11(SB),$0 PUSHL $11 JMP intrscommon TEXT intr12(SB),$0 PUSHL $12 JMP intrscommon TEXT intr13(SB),$0 PUSHL $13 JMP intrscommon TEXT intr14(SB),$0 PUSHL $14 JMP intrscommon TEXT intr15(SB),$0 PUSHL $0 PUSHL $15 JMP intrcommon TEXT intr16(SB),$0 PUSHL $0 PUSHL $16 JMP intrcommon TEXT intr24(SB),$0 PUSHL $0 PUSHL $24 JMP intrcommon TEXT intr25(SB),$0 PUSHL $0 PUSHL $25 JMP intrcommon TEXT intr26(SB),$0 PUSHL $0 PUSHL $26 JMP intrcommon TEXT intr27(SB),$0 PUSHL $0 PUSHL $27 JMP intrcommon TEXT intr28(SB),$0 PUSHL $0 PUSHL $28 JMP intrcommon TEXT intr29(SB),$0 PUSHL $0 PUSHL $29 JMP intrcommon TEXT intr30(SB),$0 PUSHL $0 PUSHL $30 JMP intrcommon TEXT intr31(SB),$0 PUSHL $0 PUSHL $31 JMP intrcommon TEXT intr32(SB),$0 PUSHL $0 PUSHL $16 JMP intrcommon TEXT intr33(SB),$0 PUSHL $0 PUSHL $33 JMP intrcommon TEXT intr34(SB),$0 PUSHL $0 PUSHL $34 JMP intrcommon TEXT intr35(SB),$0 PUSHL $0 PUSHL $35 JMP intrcommon TEXT intr36(SB),$0 PUSHL $0 PUSHL $36 JMP intrcommon TEXT intr37(SB),$0 PUSHL $0 PUSHL $37 JMP intrcommon TEXT intr38(SB),$0 PUSHL $0 PUSHL $38 JMP intrcommon TEXT intr39(SB),$0 PUSHL $0 PUSHL $39 JMP intrcommon TEXT intr64(SB),$0 PUSHL $0 PUSHL $64 JMP intrcommon TEXT intrbad(SB),$0 PUSHL $0 PUSHL $0x1ff JMP intrcommon intrcommon: PUSHL DS PUSHL ES PUSHL FS PUSHL GS PUSHAL MOVL $(KDSEL),AX MOVW AX,DS MOVW AX,ES LEAL 0(SP),AX PUSHL AX CALL trap(SB) POPL AX POPAL POPL GS POPL FS POPL ES POPL DS ADDL $8,SP /* error code and trap type */ IRETL intrscommon: PUSHL DS PUSHL ES PUSHL FS PUSHL GS PUSHAL MOVL $(KDSEL),AX MOVW AX,DS MOVW AX,ES LEAL 0(SP),AX PUSHL AX CALL trap(SB) POPL AX POPAL POPL GS POPL FS POPL ES POPL DS ADDL $8,SP /* error code and trap type */ IRETL /* * interrupt level is interrupts on or off */ TEXT spllo(SB),$0 PUSHFL POPL AX STI RET TEXT splhi(SB),$0 PUSHFL POPL AX CLI RET TEXT splx(SB),$0 MOVL s+0(FP),AX PUSHL AX POPFL RET /* * do nothing whatsoever till interrupt happens */ TEXT idle(SB),$0 HLT RET /* * label consists of a stack pointer and a PC */ TEXT gotolabel(SB),$0 MOVL l+0(FP),AX MOVL 0(AX),SP /* restore sp */ MOVL 4(AX),AX /* put return pc on the stack */ MOVL AX,0(SP) MOVL $1,AX /* return 1 */ RET TEXT setlabel(SB),$0 MOVL l+0(FP),AX MOVL SP,0(AX) /* store sp */ MOVL 0(SP),BX /* store return pc */ MOVL BX,4(AX) MOVL $0,AX /* return 0 */ RET /* * Used to get to the first process. * Set up an interrupt return frame and IRET to user level. */ TEXT touser(SB),$0 PUSHL $(UDSEL) /* old ss */ PUSHL $(USTKTOP) /* old sp */ PUSHFL /* old flags */ PUSHL $(UESEL) /* old cs */ PUSHL $(UTZERO+32) /* old pc */ MOVL $(UDSEL),AX MOVW AX,DS MOVW AX,ES MOVW AX,GS MOVW AX,FS IRETL /* * set configuration register */ TEXT config(SB),$0 MOVL l+0(FP),AX MOVL $0x3F3,DX OUTB OUTB RET