locore.s revision 1321
14Srgrimes/*- 24Srgrimes * Copyright (c) 1990 The Regents of the University of California. 34Srgrimes * All rights reserved. 44Srgrimes * 54Srgrimes * This code is derived from software contributed to Berkeley by 64Srgrimes * William Jolitz. 74Srgrimes * 84Srgrimes * Redistribution and use in source and binary forms, with or without 94Srgrimes * modification, are permitted provided that the following conditions 104Srgrimes * are met: 114Srgrimes * 1. Redistributions of source code must retain the above copyright 124Srgrimes * notice, this list of conditions and the following disclaimer. 134Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 144Srgrimes * notice, this list of conditions and the following disclaimer in the 154Srgrimes * documentation and/or other materials provided with the distribution. 164Srgrimes * 3. All advertising materials mentioning features or use of this software 174Srgrimes * must display the following acknowledgement: 184Srgrimes * This product includes software developed by the University of 194Srgrimes * California, Berkeley and its contributors. 204Srgrimes * 4. Neither the name of the University nor the names of its contributors 214Srgrimes * may be used to endorse or promote products derived from this software 224Srgrimes * without specific prior written permission. 234Srgrimes * 244Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 254Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 264Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 274Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 284Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 294Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 304Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 314Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 324Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 334Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 344Srgrimes * SUCH DAMAGE. 354Srgrimes * 36556Srgrimes * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 371321Sdg * $Id: locore.s,v 1.15 1994/02/01 04:08:54 davidg Exp $ 384Srgrimes */ 394Srgrimes 404Srgrimes/* 41757Sdg * locore.s: FreeBSD machine support for the Intel 386 42757Sdg * originally from: locore.s, by William F. Jolitz 43757Sdg * 44757Sdg * Substantially rewritten by David Greenman, Rod Grimes, 45757Sdg * Bruce Evans, Wolfgang Solfrank, and many others. 464Srgrimes */ 474Srgrimes 48757Sdg#include "npx.h" /* for NNPX */ 49757Sdg#include "assym.s" /* system definitions */ 50757Sdg#include "machine/psl.h" /* processor status longword defs */ 51757Sdg#include "machine/pte.h" /* page table entry definitions */ 52757Sdg#include "errno.h" /* error return codes */ 53757Sdg#include "machine/specialreg.h" /* x86 special registers */ 54757Sdg#include "machine/cputypes.h" /* x86 cpu type definitions */ 55757Sdg#include "syscall.h" /* system call numbers */ 56757Sdg#include "machine/asmacros.h" /* miscellaneous asm macros */ 574Srgrimes 584Srgrimes/* 59757Sdg * XXX 60757Sdg * 614Srgrimes * Note: This version greatly munged to avoid various assembler errors 624Srgrimes * that may be fixed in newer versions of gas. Perhaps newer versions 634Srgrimes * will have more pleasant appearance. 644Srgrimes */ 654Srgrimes 66200Sdg/* 674Srgrimes * PTmap is recursive pagemap at top of virtual address space. 684Srgrimes * Within PTmap, the page directory can be found (third indirection). 694Srgrimes */ 70592Srgrimes .globl _PTmap,_PTD,_PTDpde,_Sysmap 71592Srgrimes .set _PTmap,PTDPTDI << PDRSHIFT 72592Srgrimes .set _PTD,_PTmap + (PTDPTDI * NBPG) 73757Sdg .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 74592Srgrimes 75757Sdg/* Sysmap is the base address of the kernel page tables */ 76608Srgrimes .set _Sysmap,_PTmap + (KPTDI * NBPG) 774Srgrimes 784Srgrimes/* 794Srgrimes * APTmap, APTD is the alternate recursive pagemap. 804Srgrimes * It's used when modifying another process's page tables. 814Srgrimes */ 82592Srgrimes .globl _APTmap,_APTD,_APTDpde 83592Srgrimes .set _APTmap,APTDPTDI << PDRSHIFT 84592Srgrimes .set _APTD,_APTmap + (APTDPTDI * NBPG) 85757Sdg .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 864Srgrimes 874Srgrimes/* 884Srgrimes * Access to each processes kernel stack is via a region of 894Srgrimes * per-process address space (at the beginning), immediatly above 904Srgrimes * the user process stack. 914Srgrimes */ 92570Srgrimes .set _kstack,USRSTACK 93134Sdg .globl _kstack 944Srgrimes 95556Srgrimes/* 96556Srgrimes * Globals 97556Srgrimes */ 98556Srgrimes .data 99556Srgrimes .globl _esym 100757Sdg_esym: .long 0 /* ptr to end of syms */ 101134Sdg 102592Srgrimes .globl _boothowto,_bootdev,_curpcb 103134Sdg 104592Srgrimes .globl _cpu,_cold,_atdevbase 105757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 106757Sdg_cold: .long 1 /* cold till we are not */ 107757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 108757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1094Srgrimes 110757Sdg .globl _KERNend 111757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 112757Sdg 113592Srgrimes .globl _IdlePTD,_KPTphys 114757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 115757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1164Srgrimes 117757Sdg .globl _cyloffset 118757Sdg_cyloffset: .long 0 /* cylinder offset from boot blocks */ 119718Swollman 120757Sdg .globl _proc0paddr 121757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 122134Sdg 123757Sdg#ifdef BDE_DEBUGGER 124757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1251321Sdg_bdb_exists: .long 0 126757Sdg#endif 127718Swollman 128757Sdg .globl tmpstk 129974Sdg .space 0x1000 1304Srgrimestmpstk: 131134Sdg 132134Sdg 133556Srgrimes/* 134556Srgrimes * System Initialization 135556Srgrimes */ 1364Srgrimes .text 137134Sdg 138134Sdg/* 139200Sdg * btext: beginning of text section. 140200Sdg * Also the entry point (jumped to directly from the boot blocks). 141134Sdg */ 1421321SdgNON_GPROF_ENTRY(btext) 143757Sdg movw $0x1234,0x472 /* warm boot */ 1444Srgrimes jmp 1f 1451321Sdg .org 0x500 /* space for BIOS variables */ 1464Srgrimes 1474Srgrimes /* 148556Srgrimes * pass parameters on stack (howto, bootdev, unit, cyloffset, esym) 1494Srgrimes * note: (%esp) is return address of boot 1504Srgrimes * ( if we want to hold onto /boot, it's physical %esp up to _end) 1514Srgrimes */ 1524Srgrimes 1534Srgrimes 1: movl 4(%esp),%eax 154570Srgrimes movl %eax,_boothowto-KERNBASE 1554Srgrimes movl 8(%esp),%eax 156570Srgrimes movl %eax,_bootdev-KERNBASE 1574Srgrimes movl 12(%esp),%eax 158570Srgrimes movl %eax,_cyloffset-KERNBASE 159556Srgrimes movl 16(%esp),%eax 160570Srgrimes addl $KERNBASE,%eax 161570Srgrimes movl %eax,_esym-KERNBASE 162975Smartin#ifdef DISKLESS /* Copy diskless structure */ 163975Smartin movl _nfs_diskless_size-KERNBASE,%ecx 164975Smartin movl 20(%esp),%esi 165975Smartin movl $(_nfs_diskless-KERNBASE),%edi 166975Smartin rep 167975Smartin movsb 168975Smartin#endif 1694Srgrimes 170556Srgrimes /* find out our CPU type. */ 171556Srgrimes pushfl 172556Srgrimes popl %eax 173556Srgrimes movl %eax,%ecx 174556Srgrimes xorl $0x40000,%eax 175556Srgrimes pushl %eax 176556Srgrimes popfl 177556Srgrimes pushfl 178556Srgrimes popl %eax 179556Srgrimes xorl %ecx,%eax 180556Srgrimes shrl $18,%eax 181556Srgrimes andl $1,%eax 182556Srgrimes push %ecx 183556Srgrimes popfl 1841321Sdg 185556Srgrimes cmpl $0,%eax 186556Srgrimes jne 1f 187570Srgrimes movl $CPU_386,_cpu-KERNBASE 188556Srgrimes jmp 2f 189570Srgrimes1: movl $CPU_486,_cpu-KERNBASE 190556Srgrimes2: 191556Srgrimes 1924Srgrimes /* 1934Srgrimes * Finished with old stack; load new %esp now instead of later so 1944Srgrimes * we can trace this code without having to worry about the trace 1954Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 1964Srgrimes * page tables. 1974Srgrimes * 1984Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 1994Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 2004Srgrimes * program should check: 2014Srgrimes * text+data <= &stack_variable - more_space_for_stack 2024Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 2034Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 2044Srgrimes * the rest of memory is still not possible. 2054Srgrimes */ 206757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 2074Srgrimes 208570Srgrimes/* 209570Srgrimes * Virtual address space of kernel: 210570Srgrimes * 211570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 212974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 213570Srgrimes */ 214570Srgrimes 2154Srgrimes/* find end of kernel image */ 216570Srgrimes movl $_end-KERNBASE,%ecx 217757Sdg addl $NBPG-1,%ecx /* page align up */ 2184Srgrimes andl $~(NBPG-1),%ecx 2191321Sdg movl %ecx,%esi /* esi = start of free memory */ 220757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 2214Srgrimes 222757Sdg/* clear bss */ 223570Srgrimes movl $_edata-KERNBASE,%edi 224760Srgrimes subl %edi,%ecx /* get amount to clear */ 225757Sdg xorl %eax,%eax /* specify zero fill */ 2264Srgrimes cld 2274Srgrimes rep 2284Srgrimes stosb 2294Srgrimes 230608Srgrimes/* 231974Sdg * The value in esi is both the end of the kernel bss and a pointer to 232974Sdg * the kernel page directory, and is used by the rest of locore to build 233974Sdg * the tables. 234974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 235757Sdg * page table pages) is then passed on the stack to init386(first) as 236757Sdg * the value first. esi should ALWAYS be page aligned!! 237608Srgrimes */ 238757Sdg movl %esi,%ecx /* Get current first availiable address */ 239608Srgrimes 240757Sdg/* clear pagetables, page directory, stack, etc... */ 241757Sdg movl %esi,%edi /* base (page directory) */ 242974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 243757Sdg xorl %eax,%eax /* specify zero fill */ 244757Sdg cld 245757Sdg rep 246757Sdg stosb 247757Sdg 248757Sdg/* physical address of Idle proc/kernel page directory */ 249570Srgrimes movl %esi,_IdlePTD-KERNBASE 2504Srgrimes 251592Srgrimes/* 252592Srgrimes * fillkpt 253592Srgrimes * eax = (page frame address | control | status) == pte 254592Srgrimes * ebx = address of page table 255592Srgrimes * ecx = how many pages to map 256592Srgrimes */ 2574Srgrimes#define fillkpt \ 2584Srgrimes1: movl %eax,(%ebx) ; \ 259570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 2604Srgrimes addl $4,%ebx ; /* next pte */ \ 2614Srgrimes loop 1b ; 2624Srgrimes 2634Srgrimes/* 2644Srgrimes * Map Kernel 2654Srgrimes * 2664Srgrimes * First step - build page tables 2674Srgrimes */ 268757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 269757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 270757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 271757Sdg#ifdef BDE_DEBUGGER 272757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 273200Sdg jae 1f 274200Sdg movl $0xa0,%ecx 275200Sdg1: 276757Sdg#endif /* BDE_DEBUGGER */ 277757Sdg movl $PG_V|PG_KW,%eax /* having these bits set, */ 278757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 279757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 2804Srgrimes fillkpt 2814Srgrimes 282757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 283757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 284757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 285757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 286757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 287757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 288757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 289757Sdg fillkpt 290757Sdg 291757Sdg /* data and bss are r/w */ 292757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 293757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 294757Sdg subl %eax,%ecx 295757Sdg shrl $PGSHIFT,%ecx 296757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 297757Sdg fillkpt 2981321Sdg#endif /* KGDB || BDE_DEBUGGER */ 299757Sdg 300757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 301757Sdg 302974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 303757Sdg movl %esi,%eax /* phys address of PTD */ 304757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 305757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 306757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 307757Sdg shrl $PGSHIFT-2,%ebx 308757Sdg addl %esi,%ebx /* address of page directory */ 309757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 310757Sdg fillkpt 3111321Sdg 3124Srgrimes/* map I/O memory map */ 3134Srgrimes 314757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 315757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 316757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 3171046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 318757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 3194Srgrimes fillkpt 3204Srgrimes 3214Srgrimes /* map proc 0's kernel stack into user page table page */ 3224Srgrimes 323757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 324757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 325757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 326757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 327757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 328757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 329757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 3304Srgrimes fillkpt 3314Srgrimes 3324Srgrimes/* 333757Sdg * Initialize kernel page table directory 3344Srgrimes */ 3354Srgrimes /* install a pde for temporary double map of bottom of VA */ 336757Sdg movl _KPTphys-KERNBASE,%eax 337757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 338757Sdg movl %eax,(%esi) /* which is where temp maps! */ 3394Srgrimes 340757Sdg /* initialize kernel pde's */ 341974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 342757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 3434Srgrimes fillkpt 3444Srgrimes 3454Srgrimes /* install a pde recursively mapping page directory as a page table! */ 346757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 347757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 348757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 3494Srgrimes 3504Srgrimes /* install a pde to map kernel stack for proc 0 */ 351757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 352757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 353757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 3544Srgrimes 355757Sdg#ifdef BDE_DEBUGGER 3564Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 3574Srgrimes 358757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 3594Srgrimes jne 1f 360570Srgrimes movb $1,_bdb_exists-KERNBASE 3614Srgrimes1: 3624Srgrimes pushal 3634Srgrimes subl $2*6,%esp 3644Srgrimes 3654Srgrimes sgdt (%esp) 366757Sdg movl 2(%esp),%esi /* base address of current gdt */ 367570Srgrimes movl $_gdt-KERNBASE,%edi 3684Srgrimes movl %edi,2(%esp) 3694Srgrimes movl $8*18/4,%ecx 370757Sdg rep /* copy gdt */ 3714Srgrimes movsl 372570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 3734Srgrimes movb $0x92,-8+5(%edi) 3744Srgrimes 3754Srgrimes sidt 6(%esp) 376757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 377757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 3784Srgrimes movw 8(%esi),%ax 379570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 3804Srgrimes movl 8+2(%esi),%eax 381570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 382757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 3834Srgrimes movw 24(%esi),%ax 384570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 3854Srgrimes movl 24+2(%esi),%eax 386570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 3874Srgrimes 388570Srgrimes movl $_idt-KERNBASE,%edi 3894Srgrimes movl %edi,6+2(%esp) 3904Srgrimes movl $8*4/4,%ecx 391757Sdg rep /* copy idt */ 3924Srgrimes movsl 3934Srgrimes 3944Srgrimes lgdt (%esp) 3954Srgrimes lidt 6(%esp) 3964Srgrimes 3974Srgrimes addl $2*6,%esp 3984Srgrimes popal 3991321Sdg#endif /* BDE_DEBUGGER */ 4004Srgrimes 401592Srgrimes /* load base of page directory and enable mapping */ 402757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 403570Srgrimes orl $I386_CR3PAT,%eax 404757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 405757Sdg movl %cr0,%eax /* get control word */ 406757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 407757Sdg movl %eax,%cr0 /* and let's page NOW! */ 4084Srgrimes 409757Sdg pushl $begin /* jump to high mem */ 4104Srgrimes ret 4114Srgrimes 412570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 4134Srgrimes 414757Sdg .globl _Crtat /* XXX - locore should not know about */ 415757Sdg movl _Crtat,%eax /* variables of device drivers (pccons)! */ 416592Srgrimes subl $(KERNBASE+0xA0000),%eax 417757Sdg movl _atdevphys,%edx /* get pte PA */ 418757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 419757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 420757Sdg addl $KERNBASE,%edx /* add virtual base */ 421570Srgrimes movl %edx,_atdevbase 4224Srgrimes addl %eax,%edx 4234Srgrimes movl %edx,_Crtat 4244Srgrimes 425757Sdg /* set up bootstrap stack - 48 bytes */ 426570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 427757Sdg xorl %eax,%eax /* mark end of frames */ 4284Srgrimes movl %eax,%ebp 429570Srgrimes movl _proc0paddr,%eax 430570Srgrimes movl %esi,PCB_CR3(%eax) 4314Srgrimes 432757Sdg#ifdef BDE_DEBUGGER 4334Srgrimes /* relocate debugger gdt entries */ 4344Srgrimes 435757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 4364Srgrimes movl $9,%ecx 4374Srgrimesreloc_gdt: 4381321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 439757Sdg addl $8,%eax /* now KERNBASE>>24 */ 4404Srgrimes loop reloc_gdt 4414Srgrimes 4424Srgrimes cmpl $0,_bdb_exists 4434Srgrimes je 1f 4444Srgrimes int $3 4454Srgrimes1: 4461321Sdg#endif /* BDE_DEBUGGER */ 4474Srgrimes 448608Srgrimes /* 449608Srgrimes * Skip over the page tables and the kernel stack 450608Srgrimes */ 451974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 452608Srgrimes 453757Sdg pushl %esi /* value of first for init386(first) */ 454757Sdg call _init386 /* wire 386 chip for unix operation */ 455200Sdg 4564Srgrimes movl $0,_PTD 457757Sdg call _main /* autoconfiguration, mountroot etc */ 4584Srgrimes popl %esi 4594Srgrimes 460134Sdg /* 461570Srgrimes * now we've run main() and determined what cpu-type we are, we can 462570Srgrimes * enable WP mode on i486 cpus and above. 4631058Sdg */ 4641058Sdg#if defined(I486_CPU) || defined(I586_CPU) 4651058Sdg cmpl $CPUCLASS_386,_cpu_class 4661058Sdg je 1f 4671058Sdg movl %cr0,%eax /* get control word */ 4681058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 4691058Sdg movl %eax,%cr0 /* and do it */ 4701058Sdg#endif 4711058Sdg /* 472134Sdg * on return from main(), we are process 1 473134Sdg * set up address space and stack so that we can 'return' to user mode 474134Sdg */ 4751058Sdg1: 476570Srgrimes .globl __ucodesel,__udatasel 4774Srgrimes movl __ucodesel,%eax 4784Srgrimes movl __udatasel,%ecx 479570Srgrimes /* build outer stack frame */ 480757Sdg pushl %ecx /* user ss */ 481757Sdg pushl $USRSTACK /* user esp */ 482757Sdg pushl %eax /* user cs */ 483757Sdg pushl $0 /* user ip */ 4844Srgrimes movl %cx,%ds 4854Srgrimes movl %cx,%es 486757Sdg movl %ax,%fs /* double map cs to fs */ 487757Sdg movl %cx,%gs /* and ds to gs */ 488757Sdg lret /* goto user! */ 4894Srgrimes 490757Sdg pushl $lretmsg1 /* "should never get here!" */ 4914Srgrimes call _panic 4924Srgrimeslretmsg1: 4934Srgrimes .asciz "lret: toinit\n" 4944Srgrimes 4954Srgrimes 4961321Sdg#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 4974Srgrimes/* 498134Sdg * Icode is copied out to process 1 and executed in user mode: 499134Sdg * execve("/sbin/init", argv, envp); exit(0); 500200Sdg * If the execve fails, process 1 exits and the system panics. 5014Srgrimes */ 502200SdgNON_GPROF_ENTRY(icode) 503757Sdg pushl $0 /* envp for execve() */ 504200Sdg 505757Sdg# pushl $argv-_icode /* can't do this 'cos gas 1.38 is broken */ 5064Srgrimes movl $argv,%eax 5074Srgrimes subl $_icode,%eax 508757Sdg pushl %eax /* argp for execve() */ 5094Srgrimes 510570Srgrimes# pushl $init-_icode 5114Srgrimes movl $init,%eax 5124Srgrimes subl $_icode,%eax 513757Sdg pushl %eax /* fname for execve() */ 5144Srgrimes 515757Sdg pushl %eax /* dummy return address */ 516200Sdg 517757Sdg movl $SYS_execve,%eax 5184Srgrimes LCALL(0x7,0x0) 519200Sdg 520570Srgrimes /* exit if something botches up in the above execve() */ 521757Sdg pushl %eax /* execve failed, the errno will do for an */ 522757Sdg /* exit code because errnos are < 128 */ 523757Sdg pushl %eax /* dummy return address */ 524757Sdg movl $SYS_exit,%eax 5254Srgrimes LCALL(0x7,0x0) 5264Srgrimes 5274Srgrimesinit: 5284Srgrimes .asciz "/sbin/init" 5294Srgrimes ALIGN_DATA 5304Srgrimesargv: 531757Sdg .long init+6-_icode /* argv[0] = "init" ("/sbin/init" + 6) */ 532757Sdg .long eicode-_icode /* argv[1] follows icode after copyout */ 5334Srgrimes .long 0 5344Srgrimeseicode: 5354Srgrimes 5364Srgrimes .globl _szicode 5374Srgrimes_szicode: 5384Srgrimes .long _szicode-_icode 5394Srgrimes 540200SdgNON_GPROF_ENTRY(sigcode) 541592Srgrimes call SIGF_HANDLER(%esp) 542757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 543757Sdg /* copy at 8(%esp)) */ 5444Srgrimes pushl %eax 545757Sdg pushl %eax /* junk to fake return address */ 546757Sdg movl $103,%eax /* XXX sigreturn() */ 547757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 548757Sdg hlt /* never gets here */ 5494Srgrimes 5504Srgrimes .globl _szsigcode 5514Srgrimes_szsigcode: 5524Srgrimes .long _szsigcode-_sigcode 553