Map the kernel text read-only if !DDB. Also, shorten many parts of the page
table startup by judicious application of lea.
This commit is contained in:
mycroft
parent
3f30686b83
commit
9f00060fdf
|
|
@ -37,7 +37,7 @@
|
|||
* SUCH DAMAGE.
|
||||
*
|
||||
* from: @(#)locore.s 7.3 (Berkeley) 5/13/91
|
||||
* $Id: locore.s,v 1.85 1994/10/09 09:19:29 mycroft Exp $
|
||||
* $Id: locore.s,v 1.86 1994/10/25 14:31:24 mycroft Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
|
|
@ -360,24 +360,25 @@ try586: /* Use the `cpuid' instruction. */
|
|||
stosl
|
||||
|
||||
/* Find end of kernel image. */
|
||||
movl $(_end-KERNBASE),%ecx
|
||||
movl $(_end-KERNBASE),%edi
|
||||
#if defined(DDB) && !defined(SYMTAB_SPACE)
|
||||
/* Save the symbols (if loaded). */
|
||||
movl _esym-KERNBASE,%eax
|
||||
testl %eax,%eax
|
||||
jz 1f
|
||||
movl %eax,%ecx
|
||||
subl $KERNBASE,%ecx
|
||||
subl $KERNBASE,%eax
|
||||
movl %eax,%edi
|
||||
1:
|
||||
#endif
|
||||
movl %ecx,%edi # edi = esym ?: end
|
||||
addl $PGOFSET,%ecx # page align up
|
||||
andl $(~PGOFSET),%ecx
|
||||
movl %ecx,%esi # esi = start of tables
|
||||
subl %edi,%ecx
|
||||
addl $((NKPDE+UPAGES+2)*NBPG),%ecx # size of tables
|
||||
|
||||
|
||||
/* Calculate where to start the bootstrap tables. */
|
||||
movl %edi,%esi # edi = esym ?: end
|
||||
addl $PGOFSET,%esi # page align up
|
||||
andl $~PGOFSET,%esi
|
||||
|
||||
/* Clear memory for bootstrap tables. */
|
||||
leal ((2+UPAGES+NKPDE)*NBPG)(%esi),%ecx # end of tables
|
||||
subl %edi,%ecx # size of tables
|
||||
shrl $2,%ecx
|
||||
xorl %eax,%eax
|
||||
cld
|
||||
|
|
@ -401,53 +402,71 @@ try586: /* Use the `cpuid' instruction. */
|
|||
/*
|
||||
* Build initial page tables.
|
||||
*/
|
||||
/* First, map the kernel text, data, and BSS. */
|
||||
movl %esi,%ecx # this much memory,
|
||||
shrl $PGSHIFT,%ecx # for this many pte s
|
||||
addl $(NKPDE+UPAGES+2),%ecx # including our early context
|
||||
movl $(PG_V|PG_KW),%eax # having these bits set,
|
||||
leal ((UPAGES+2)*NBPG)(%esi),%ebx # physical address of KPT in proc 0,
|
||||
movl %ebx,_KPTphys-KERNBASE # in the kernel page table,
|
||||
leal ((2+UPAGES)*NBPG)(%esi),%ebx # physical address of KPT in proc 0,
|
||||
movl %ebx,_KPTphys-KERNBASE # in the kernel page table,
|
||||
|
||||
/* XXX Map the first MB of memory read-write. */
|
||||
movl $(0+PG_V|PG_KW),%eax # having these bits set,
|
||||
movl $(KERNTEXTOFF-KERNBASE),%ecx
|
||||
shrl $PGSHIFT,%ecx
|
||||
fillkpt
|
||||
|
||||
/* Calculate end of text segment, rounded to a page. */
|
||||
leal (_etext-KERNBASE+PGOFSET),%edx
|
||||
andl $~PGOFSET,%edx
|
||||
|
||||
/* Map the kernel text read-only. */
|
||||
leal (KERNBASE-KERNTEXTOFF)(%edx),%ecx
|
||||
shrl $PGSHIFT,%ecx
|
||||
andl $PG_FRAME,%eax
|
||||
#ifdef DDB
|
||||
orl $(PG_V|PG_KW),%eax
|
||||
#else
|
||||
orl $(PG_V|PG_KR),%eax
|
||||
#endif
|
||||
fillkpt
|
||||
|
||||
/* Map the data, BSS, and bootstrap tables read-write. */
|
||||
leal ((2+UPAGES+NKPDE)*NBPG)(%esi),%ecx # end of tables
|
||||
subl %edx,%ecx # subtract end of text
|
||||
shrl $PGSHIFT,%ecx
|
||||
andl $PG_FRAME,%eax
|
||||
orl $(PG_V|PG_KW),%eax
|
||||
fillkpt
|
||||
|
||||
/* Map ISA I/O memory. */
|
||||
movl $(IOM_SIZE>>PGSHIFT),%ecx # for this many pte s,
|
||||
movl $(IOM_BEGIN|PG_V|PG_UW/*|PG_N*/),%eax # having these bits set
|
||||
movl %ebx,_atdevphys-KERNBASE # remember phys addr of ptes
|
||||
movl $(IOM_SIZE>>PGSHIFT),%ecx # for this many pte s,
|
||||
movl $(IOM_BEGIN|PG_V|PG_KW/*|PG_N*/),%eax # having these bits set
|
||||
movl %ebx,_atdevphys-KERNBASE # remember phys addr of ptes
|
||||
fillkpt
|
||||
|
||||
/* Map proc 0's kernel stack into user page table page. */
|
||||
movl $UPAGES,%ecx # for this many pte s,
|
||||
leal (2*NBPG)(%esi),%eax # physical address in proc 0
|
||||
leal (KERNBASE)(%eax),%edx
|
||||
movl %edx,_proc0paddr-KERNBASE # remember VA for 0th process init
|
||||
orl $(PG_V|PG_KW),%eax # having these bits set,
|
||||
leal (1*NBPG)(%esi),%ebx # physical address of stack pt in proc 0
|
||||
addl $((NPTEPD-UPAGES)*4),%ebx
|
||||
movl $UPAGES,%ecx # for this many pte s,
|
||||
leal (2*NBPG+KERNBASE)(%esi),%edx
|
||||
movl %edx,_proc0paddr-KERNBASE # remember VA for 0th process init
|
||||
leal (2*NBPG+PG_V|PG_KW)(%esi),%eax # physical address in proc 0
|
||||
leal (2*NBPG-UPAGES*4)(%esi),%ebx # physical address of stack pt in proc 0
|
||||
fillkpt
|
||||
|
||||
/*
|
||||
* Construct a page table directory.
|
||||
*/
|
||||
/* Install a PDE for temporary double map of kernel text. */
|
||||
movl _KPTphys-KERNBASE,%eax # physical address of kernel page tables
|
||||
orl $(PG_V|PG_UW),%eax # pde entry is valid
|
||||
movl %eax,(%esi) # which is where temp maps!
|
||||
leal ((2+UPAGES)*NBPG+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
|
||||
movl %eax,(%esi) # which is where temp maps!
|
||||
|
||||
/* Map kernel PDEs. */
|
||||
movl $NKPDE,%ecx # for this many pde s,
|
||||
leal (KPTDI*4)(%esi),%ebx # offset of pde for kernel
|
||||
movl $NKPDE,%ecx # for this many pde s,
|
||||
leal (KPTDI*4)(%esi),%ebx # offset of pde for kernel
|
||||
fillkpt
|
||||
|
||||
/* Install a PDE recursively mapping page directory as a page table! */
|
||||
movl %esi,%eax # phys address of ptd in proc 0
|
||||
orl $(PG_V|PG_UW),%eax # pde entry is valid
|
||||
movl %eax,(PTDPTDI*4)(%esi) # which is where PTmap maps!
|
||||
leal (0*NBPG+PG_V|PG_KW)(%esi),%eax # pte for ptd
|
||||
movl %eax,(PTDPTDI*4)(%esi) # which is where PTmap maps!
|
||||
|
||||
/* Install a PDE to map kernel stack for proc 0. */
|
||||
leal (1*NBPG)(%esi),%eax # physical address of pt in proc 0
|
||||
orl $(PG_V|PG_KW),%eax # pde entry is valid
|
||||
movl %eax,(UPTDI*4)(%esi) # which is where kernel stack maps!
|
||||
leal (1*NBPG+PG_V|PG_KW)(%esi),%eax # pte for pt in proc 0
|
||||
movl %eax,(UPTDI*4)(%esi) # which is where kernel stack maps!
|
||||
|
||||
#ifdef BDB
|
||||
/* Copy and convert stuff from old GDT and IDT for debugger. */
|
||||
|
|
|
|||
Loading…
Reference in New Issue