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-rw-r--r--sys/amd64/amd64/locore.S259
-rw-r--r--sys/amd64/amd64/locore.s259
-rw-r--r--sys/i386/i386/locore.s259
3 files changed, 615 insertions, 162 deletions
diff --git a/sys/amd64/amd64/locore.S b/sys/amd64/amd64/locore.S
index 0b7a78990815..fbbb9261a7ba 100644
--- a/sys/amd64/amd64/locore.S
+++ b/sys/amd64/amd64/locore.S
@@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)locore.s 7.3 (Berkeley) 5/13/91
- * $Id: locore.s,v 1.65 1996/04/26 13:47:37 phk Exp $
+ * $Id: locore.s,v 1.66 1996/04/26 22:26:45 bde Exp $
*
* originally from: locore.s, by William F. Jolitz
*
@@ -92,7 +92,7 @@
/*
* Access to each processes kernel stack is via a region of
- * per-process address space (at the beginning), immediatly above
+ * per-process address space (at the beginning), immediately above
* the user process stack.
*/
.set _kstack,USRSTACK
@@ -122,9 +122,9 @@ _bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */
_atdevbase: .long 0 /* location of start of iomem in virtual */
_KERNend: .long 0 /* phys addr end of kernel (just after bss) */
-physfree: .long 0 /* phys addr end of kernel (just after bss) */
-upa: .long 0 /* phys addr end of kernel (just after bss) */
-p0s: .long 0 /* phys addr end of kernel (just after bss) */
+physfree: .long 0 /* phys addr of next free page */
+upa: .long 0 /* phys addr of proc0's UPAGES */
+p0upt: .long 0 /* phys addr of proc0's UPAGES page table */
.globl _IdlePTD
_IdlePTD: .long 0 /* phys addr of kernel PTD */
@@ -134,6 +134,11 @@ _KPTphys: .long 0 /* phys addr of kernel page tables */
.globl _proc0paddr
_proc0paddr: .long 0 /* address of proc 0 address space */
+#ifdef BDE_DEBUGGER
+ .globl _bdb_exists /* flag to indicate BDE debugger is present */
+_bdb_exists: .long 0
+#endif
+
/**********************************************************************
*
@@ -143,8 +148,6 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
#define R(foo) ((foo)-KERNBASE)
-#define ROUND2PAGE(foo) addl $NBPG-1, foo; andl $~(NBPG-1), foo
-
#define ALLOCPAGES(foo) \
movl R(physfree), %esi ; \
movl $((foo)*NBPG), %eax ; \
@@ -153,7 +156,9 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
movl %esi, %edi ; \
movl $((foo)*NBPG),%ecx ; \
xorl %eax,%eax ; \
- cld ; rep ; stosb
+ cld ; \
+ rep ; \
+ stosb
/*
* fillkpt
@@ -165,7 +170,7 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
1: movl %eax,(%ebx) ; \
addl $NBPG,%eax ; /* increment physical address */ \
addl $4,%ebx ; /* next pte */ \
- loop 1b ;
+ loop 1b
.text
/**********************************************************************
@@ -175,43 +180,90 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
*/
NON_GPROF_ENTRY(btext)
+#ifdef BDE_DEBUGGER
+#ifdef BIOS_STEALS_3K
+ cmpl $0x0375c339,0x95504
+#else
+ cmpl $0x0375c339,0x96104 /* XXX - debugger signature */
+#endif
+ jne 1f
+ movb $1,R(_bdb_exists)
+1:
+#endif
+
/* Tell the bios to warmboot next time */
movw $0x1234,0x472
-/* Set up a real frame, some day we may be doing returns */
+/* Set up a real frame in case the double return in newboot is executed. */
pushl %ebp
movl %esp, %ebp
/* Don't trust what the BIOS gives for eflags. */
pushl $PSL_KERNEL
popfl
- mov %ds, %ax /* ... or segment registers */
- mov %ax, %es
+
+/*
+ * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap
+ * to set %cs, %ds, %es and %ss.
+ */
+ mov %ds, %ax
mov %ax, %fs
mov %ax, %gs
call recover_bootinfo
-/* get onto a stack we know the size of */
+/* Get onto a stack that we can trust. */
+/*
+ * XXX this step is delayed in case recover_bootinfo needs to return via
+ * the old stack, but it need not be, since recover_bootinfo actually
+ * returns via the old frame.
+ */
movl $R(tmpstk),%esp
- mov %ds, %ax
- mov %ax, %ss
call identify_cpu
/* clear bss */
+/*
+ * XXX this should be done a little earlier. (bde)
+ *
+ * XXX we don't check that there is memory for our bss or page tables
+ * before using it. (bde)
+ *
+ * XXX the boot program somewhat bogusly clears the bss. We still have
+ * to do it in case we were unzipped by kzipboot. Then the boot program
+ * only clears kzipboot's bss.
+ *
+ * XXX the gdt and idt are still somewhere in the boot program. We
+ * depend on the convention that the boot program is below 1MB and we
+ * are above 1MB to keep the gdt and idt away from the bss and page
+ * tables. The idT is only used if BDE_DEBUGGER is enabled.
+ */
movl $R(_end),%ecx
movl $R(_edata),%edi
subl %edi,%ecx
xorl %eax,%eax
- cld ; rep ; stosb
+ cld
+ rep
+ stosb
#if NAPM > 0
- call _apm_setup /* ... in i386/apm/apm_setup.s */
-#endif /* NAPM */
+/*
+ * XXX it's not clear that APM can live in the current environonment.
+ * Only pc-relative addressing works.
+ */
+ call _apm_setup
+#endif
call create_pagetables
+#ifdef BDE_DEBUGGER
+/*
+ * Adjust as much as possible for paging before enabling paging so that the
+ * adjustments can be traced.
+ */
+ call bdb_prepare_paging
+#endif
+
/* Now enable paging */
movl R(_IdlePTD), %eax
movl %eax,%cr3 /* load ptd addr into mmu */
@@ -219,7 +271,16 @@ NON_GPROF_ENTRY(btext)
orl $CR0_PE|CR0_PG,%eax /* enable paging */
movl %eax,%cr0 /* and let's page NOW! */
- pushl $begin /* jump to high mem */
+#ifdef BDE_DEBUGGER
+/*
+ * Complete the adjustments for paging so that we can keep tracing through
+ * initi386() after the low (physical) addresses for the gdt and idT become
+ * invalid.
+ */
+ call bdb_commit_paging
+#endif
+
+ pushl $begin /* jump to high virtualized address */
ret
/* now running relocated at KERNBASE where the system is linked to run */
@@ -232,10 +293,6 @@ begin:
movl _IdlePTD, %esi
movl %esi,PCB_CR3(%eax)
- /*
- * Prepare "first" - physical address of first available page
- * after the kernel+pdir+upages+p0stack+page tables
- */
movl physfree, %esi
pushl %esi /* value of first for init386(first) */
call _init386 /* wire 386 chip for unix operation */
@@ -267,12 +324,12 @@ begin:
movl %cr0,%eax /* get control word */
orl $CR0_WP|CR0_AM,%eax /* enable i486 features */
movl %eax,%cr0 /* and do it */
+1:
#endif
/*
* on return from main(), we are process 1
* set up address space and stack so that we can 'return' to user mode
*/
-1:
movl __ucodesel,%eax
movl __udatasel,%ecx
@@ -303,6 +360,7 @@ _esigcode:
.globl _szsigcode
_szsigcode:
.long _esigcode-_sigcode
+ .text
/**********************************************************************
*
@@ -349,8 +407,8 @@ recover_bootinfo:
/*
* We have some form of return address, so this is either the
* old diskless netboot code, or the new uniform code. That can
- * be detected by looking at the 5th argument, it if is 0 we
- * we are being booted by the new unifrom boot code.
+ * be detected by looking at the 5th argument, if it is 0
+ * we are being booted by the new uniform boot code.
*/
cmpl $0,24(%ebp)
je newboot
@@ -364,7 +422,7 @@ recover_bootinfo:
/*
* We have been loaded by the new uniform boot code.
- * Lets check the bootinfo version, and if we do not understand
+ * Let's check the bootinfo version, and if we do not understand
* it we return to the loader with a status of 1 to indicate this error
*/
newboot:
@@ -373,8 +431,11 @@ newboot:
cmpl $1,%eax /* We only understand version 1 */
je 1f
movl $1,%eax /* Return status */
- add $4, %esp /* pop recover_bootinfo's retaddr */
leave
+ /*
+ * XXX this returns to our caller's caller (as is required) since
+ * we didn't set up a frame and our caller did.
+ */
ret
1:
@@ -397,7 +458,7 @@ newboot:
movsb
2:
- /*
+ /*
* Determine the size of the boot loader's copy of the bootinfo
* struct. This is impossible to do properly because old versions
* of the struct don't contain a size field and there are 2 old
@@ -409,7 +470,7 @@ newboot:
movl BI_SIZE(%ebx),%ecx
got_bi_size:
- /*
+ /*
* Copy the common part of the bootinfo struct
*/
movl %ebx,%esi
@@ -428,7 +489,7 @@ got_common_bi_size:
*/
movl BI_NFS_DISKLESS(%ebx),%esi
cmpl $0,%esi
- je 2f
+ je olddiskboot
lea _nfs_diskless-KERNBASE,%edi
movl $NFSDISKLESS_SIZE,%ecx
cld
@@ -540,9 +601,9 @@ identify_cpu:
andb $~CCR0_NC0,%al
#ifndef CYRIX_CACHE_REALLY_WORKS
orb $(CCR0_NC1|CCR0_BARB),%al
-#else /* !CYRIX_CACHE_REALLY_WORKS */
+#else /* CYRIX_CACHE_REALLY_WORKS */
orb $CCR0_NC1,%al
-#endif /* CYRIX_CACHE_REALLY_WORKS */
+#endif /* !CYRIX_CACHE_REALLY_WORKS */
movb %al,%ah
movb $CCR0,%al
outb %al,$0x22
@@ -573,7 +634,7 @@ identify_cpu:
andl $~(CR0_CD|CR0_NW),%eax
movl %eax,%cr0
invd
-#endif /* CYRIX_CACHE_WORKS */
+#endif /* !CYRIX_CACHE_WORKS */
jmp 3f
1: /* Use the `cpuid' instruction. */
@@ -612,30 +673,31 @@ identify_cpu:
/**********************************************************************
*
- * Create the first page directory and it's page tables
+ * Create the first page directory and its page tables.
*
*/
create_pagetables:
-/* find end of kernel image */
+/* Find end of kernel image (rounded up to a page boundary). */
movl $R(_end),%esi
/* include symbols in "kernel image" if they are loaded and useful */
#ifdef DDB
movl R(_bootinfo+BI_ESYMTAB),%edi
testl %edi,%edi
- je 1f
+ je over_symalloc
movl %edi,%esi
movl $KERNBASE,%edi
addl %edi,R(_bootinfo+BI_SYMTAB)
addl %edi,R(_bootinfo+BI_ESYMTAB)
-1:
+over_symalloc:
#endif
- ROUND2PAGE(%esi)
+ addl $NBPG-1,%esi
+ andl $~(NBPG-1),%esi
movl %esi,R(_KERNend) /* save end of kernel */
- movl %esi,R(physfree) /* save end of kernel */
+ movl %esi,R(physfree) /* next free page is at end of kernel */
/* Allocate Kernel Page Tables */
ALLOCPAGES(NKPT)
@@ -647,13 +709,13 @@ create_pagetables:
/* Allocate UPAGES */
ALLOCPAGES(UPAGES)
- movl %esi,R(upa);
+ movl %esi,R(upa)
addl $KERNBASE, %esi
movl %esi, R(_proc0paddr)
-/* Allocate P0 Stack */
+/* Allocate proc0's page table for the UPAGES. */
ALLOCPAGES(1)
- movl %esi,R(p0s);
+ movl %esi,R(p0upt)
/* Map read-only from zero to the end of the kernel text section */
movl R(_KPTphys), %esi
@@ -662,17 +724,23 @@ create_pagetables:
shrl $PGSHIFT,%ecx
movl $PG_V|PG_KR,%eax
movl %esi, %ebx
+#ifdef BDE_DEBUGGER
+/* If the debugger is present, actually map everything read-write. */
+ cmpl $0,R(_bdb_exists)
+ jne map_read_write
+#endif
fillkpt
/* Map read-write, data, bss and symbols */
- andl $PG_FRAME,%eax
+map_read_write:
+ andl $PG_FRAME,%eax
movl R(_KERNend),%ecx
subl %eax,%ecx
shrl $PGSHIFT,%ecx
orl $PG_V|PG_KW,%eax
fillkpt
-/* Map PD */
+/* Map page directory. */
movl R(_IdlePTD), %eax
movl $1, %ecx
movl %eax, %ebx
@@ -681,8 +749,8 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* Map Proc 0 kernel stack */
- movl R(p0s), %eax
+/* Map proc0's page table for the UPAGES the physical way. */
+ movl R(p0upt), %eax
movl $1, %ecx
movl %eax, %ebx
shrl $PGSHIFT-2, %ebx
@@ -690,15 +758,15 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
- movl R(p0s), %eax
+/* ... and the virtual way */
+ movl R(p0upt), %eax
movl $1, %ecx
orl $PG_V|PG_KW, %eax
movl R(_KPTphys), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* Map UPAGES */
+/* Map proc0s UPAGES the physical way */
movl R(upa), %eax
movl $UPAGES, %ecx
movl %eax, %ebx
@@ -707,16 +775,16 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
+/* ... and in the special page table for this purpose. */
movl R(upa), %eax
movl $UPAGES, %ecx
orl $PG_V|PG_KW, %eax
- movl R(p0s), %ebx
+ movl R(p0upt), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* and a pde entry too */
- movl R(p0s), %eax
+/* and put the page table in the pde. */
+ movl R(p0upt), %eax
movl R(_IdlePTD), %esi
orl $PG_V|PG_KW,%eax
movl %eax,KSTKPTDI*PDESIZE(%esi)
@@ -727,10 +795,13 @@ create_pagetables:
movl $ISA_HOLE_LENGTH>>PGSHIFT, %ecx
movl $ISA_HOLE_START, %eax
movl %eax, %ebx
+/* XXX 2 is magic for log2(PTESIZE). */
shrl $PGSHIFT-2, %ebx
addl R(_KPTphys), %ebx
+/* XXX could load %eax directly with $ISA_HOLE_START|PG_V|PG_KW_PG_N. */
orl $PG_V|PG_KW|PG_N, %eax
fillkpt
+/* XXX could load %eax directly with $ISA_HOLE_START+KERNBASE. */
movl $ISA_HOLE_START, %eax
addl $KERNBASE, %eax
movl %eax, R(_atdevbase)
@@ -756,3 +827,83 @@ create_pagetables:
movl %eax,PTDPTDI*PDESIZE(%esi)
ret
+
+#ifdef BDE_DEBUGGER
+bdb_prepare_paging:
+ cmpl $0,R(_bdb_exists)
+ je bdb_prepare_paging_exit
+
+ subl $6,%esp
+
+ /*
+ * Copy and convert debugger entries from the bootstrap gdt and idt
+ * to the kernel gdt and idt. Everything is still in low memory.
+ * Tracing continues to work after paging is enabled because the
+ * low memory addresses remain valid until everything is relocated.
+ * However, tracing through the setidt() that initializes the trace
+ * trap will crash.
+ */
+ sgdt (%esp)
+ movl 2(%esp),%esi /* base address of bootstrap gdt */
+ movl $R(_gdt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel gdt */
+ movl $8*18/4,%ecx
+ cld
+ rep /* copy gdt */
+ movsl
+ movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */
+ movb $0x92,-8+5(%edi)
+ lgdt (%esp)
+
+ sidt (%esp)
+ movl 2(%esp),%esi /* base address of current idt */
+ movl 8+4(%esi),%eax /* convert dbg descriptor to ... */
+ movw 8(%esi),%ax
+ movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */
+ movl 8+2(%esi),%eax
+ movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */
+ movl 24+4(%esi),%eax /* same for bpt descriptor */
+ movw 24(%esi),%ax
+ movl %eax,R(bdb_bpt_ljmp+1)
+ movl 24+2(%esi),%eax
+ movw %ax,R(bdb_bpt_ljmp+5)
+ movl $R(_idt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel idt */
+ movl $8*4/4,%ecx
+ cld
+ rep /* copy idt */
+ movsl
+ lidt (%esp)
+
+ addl $6,%esp
+
+bdb_prepare_paging_exit:
+ ret
+
+/* Relocate debugger gdt entries and gdt and idt pointers. */
+bdb_commit_paging:
+ cmpl $0,_bdb_exists
+ je bdb_commit_paging_exit
+
+ movl $_gdt+8*9,%eax /* adjust slots 9-17 */
+ movl $9,%ecx
+reloc_gdt:
+ movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */
+ addl $8,%eax /* now KERNBASE>>24 */
+ loop reloc_gdt
+
+ subl $6,%esp
+ sgdt (%esp)
+ addl $KERNBASE,2(%esp)
+ lgdt (%esp)
+ sidt (%esp)
+ addl $KERNBASE,2(%esp)
+ lidt (%esp)
+ addl $6,%esp
+
+ int $3
+
+bdb_commit_paging_exit:
+ ret
+
+#endif /* BDE_DEBUGGER */
diff --git a/sys/amd64/amd64/locore.s b/sys/amd64/amd64/locore.s
index 0b7a78990815..fbbb9261a7ba 100644
--- a/sys/amd64/amd64/locore.s
+++ b/sys/amd64/amd64/locore.s
@@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)locore.s 7.3 (Berkeley) 5/13/91
- * $Id: locore.s,v 1.65 1996/04/26 13:47:37 phk Exp $
+ * $Id: locore.s,v 1.66 1996/04/26 22:26:45 bde Exp $
*
* originally from: locore.s, by William F. Jolitz
*
@@ -92,7 +92,7 @@
/*
* Access to each processes kernel stack is via a region of
- * per-process address space (at the beginning), immediatly above
+ * per-process address space (at the beginning), immediately above
* the user process stack.
*/
.set _kstack,USRSTACK
@@ -122,9 +122,9 @@ _bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */
_atdevbase: .long 0 /* location of start of iomem in virtual */
_KERNend: .long 0 /* phys addr end of kernel (just after bss) */
-physfree: .long 0 /* phys addr end of kernel (just after bss) */
-upa: .long 0 /* phys addr end of kernel (just after bss) */
-p0s: .long 0 /* phys addr end of kernel (just after bss) */
+physfree: .long 0 /* phys addr of next free page */
+upa: .long 0 /* phys addr of proc0's UPAGES */
+p0upt: .long 0 /* phys addr of proc0's UPAGES page table */
.globl _IdlePTD
_IdlePTD: .long 0 /* phys addr of kernel PTD */
@@ -134,6 +134,11 @@ _KPTphys: .long 0 /* phys addr of kernel page tables */
.globl _proc0paddr
_proc0paddr: .long 0 /* address of proc 0 address space */
+#ifdef BDE_DEBUGGER
+ .globl _bdb_exists /* flag to indicate BDE debugger is present */
+_bdb_exists: .long 0
+#endif
+
/**********************************************************************
*
@@ -143,8 +148,6 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
#define R(foo) ((foo)-KERNBASE)
-#define ROUND2PAGE(foo) addl $NBPG-1, foo; andl $~(NBPG-1), foo
-
#define ALLOCPAGES(foo) \
movl R(physfree), %esi ; \
movl $((foo)*NBPG), %eax ; \
@@ -153,7 +156,9 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
movl %esi, %edi ; \
movl $((foo)*NBPG),%ecx ; \
xorl %eax,%eax ; \
- cld ; rep ; stosb
+ cld ; \
+ rep ; \
+ stosb
/*
* fillkpt
@@ -165,7 +170,7 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
1: movl %eax,(%ebx) ; \
addl $NBPG,%eax ; /* increment physical address */ \
addl $4,%ebx ; /* next pte */ \
- loop 1b ;
+ loop 1b
.text
/**********************************************************************
@@ -175,43 +180,90 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
*/
NON_GPROF_ENTRY(btext)
+#ifdef BDE_DEBUGGER
+#ifdef BIOS_STEALS_3K
+ cmpl $0x0375c339,0x95504
+#else
+ cmpl $0x0375c339,0x96104 /* XXX - debugger signature */
+#endif
+ jne 1f
+ movb $1,R(_bdb_exists)
+1:
+#endif
+
/* Tell the bios to warmboot next time */
movw $0x1234,0x472
-/* Set up a real frame, some day we may be doing returns */
+/* Set up a real frame in case the double return in newboot is executed. */
pushl %ebp
movl %esp, %ebp
/* Don't trust what the BIOS gives for eflags. */
pushl $PSL_KERNEL
popfl
- mov %ds, %ax /* ... or segment registers */
- mov %ax, %es
+
+/*
+ * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap
+ * to set %cs, %ds, %es and %ss.
+ */
+ mov %ds, %ax
mov %ax, %fs
mov %ax, %gs
call recover_bootinfo
-/* get onto a stack we know the size of */
+/* Get onto a stack that we can trust. */
+/*
+ * XXX this step is delayed in case recover_bootinfo needs to return via
+ * the old stack, but it need not be, since recover_bootinfo actually
+ * returns via the old frame.
+ */
movl $R(tmpstk),%esp
- mov %ds, %ax
- mov %ax, %ss
call identify_cpu
/* clear bss */
+/*
+ * XXX this should be done a little earlier. (bde)
+ *
+ * XXX we don't check that there is memory for our bss or page tables
+ * before using it. (bde)
+ *
+ * XXX the boot program somewhat bogusly clears the bss. We still have
+ * to do it in case we were unzipped by kzipboot. Then the boot program
+ * only clears kzipboot's bss.
+ *
+ * XXX the gdt and idt are still somewhere in the boot program. We
+ * depend on the convention that the boot program is below 1MB and we
+ * are above 1MB to keep the gdt and idt away from the bss and page
+ * tables. The idT is only used if BDE_DEBUGGER is enabled.
+ */
movl $R(_end),%ecx
movl $R(_edata),%edi
subl %edi,%ecx
xorl %eax,%eax
- cld ; rep ; stosb
+ cld
+ rep
+ stosb
#if NAPM > 0
- call _apm_setup /* ... in i386/apm/apm_setup.s */
-#endif /* NAPM */
+/*
+ * XXX it's not clear that APM can live in the current environonment.
+ * Only pc-relative addressing works.
+ */
+ call _apm_setup
+#endif
call create_pagetables
+#ifdef BDE_DEBUGGER
+/*
+ * Adjust as much as possible for paging before enabling paging so that the
+ * adjustments can be traced.
+ */
+ call bdb_prepare_paging
+#endif
+
/* Now enable paging */
movl R(_IdlePTD), %eax
movl %eax,%cr3 /* load ptd addr into mmu */
@@ -219,7 +271,16 @@ NON_GPROF_ENTRY(btext)
orl $CR0_PE|CR0_PG,%eax /* enable paging */
movl %eax,%cr0 /* and let's page NOW! */
- pushl $begin /* jump to high mem */
+#ifdef BDE_DEBUGGER
+/*
+ * Complete the adjustments for paging so that we can keep tracing through
+ * initi386() after the low (physical) addresses for the gdt and idT become
+ * invalid.
+ */
+ call bdb_commit_paging
+#endif
+
+ pushl $begin /* jump to high virtualized address */
ret
/* now running relocated at KERNBASE where the system is linked to run */
@@ -232,10 +293,6 @@ begin:
movl _IdlePTD, %esi
movl %esi,PCB_CR3(%eax)
- /*
- * Prepare "first" - physical address of first available page
- * after the kernel+pdir+upages+p0stack+page tables
- */
movl physfree, %esi
pushl %esi /* value of first for init386(first) */
call _init386 /* wire 386 chip for unix operation */
@@ -267,12 +324,12 @@ begin:
movl %cr0,%eax /* get control word */
orl $CR0_WP|CR0_AM,%eax /* enable i486 features */
movl %eax,%cr0 /* and do it */
+1:
#endif
/*
* on return from main(), we are process 1
* set up address space and stack so that we can 'return' to user mode
*/
-1:
movl __ucodesel,%eax
movl __udatasel,%ecx
@@ -303,6 +360,7 @@ _esigcode:
.globl _szsigcode
_szsigcode:
.long _esigcode-_sigcode
+ .text
/**********************************************************************
*
@@ -349,8 +407,8 @@ recover_bootinfo:
/*
* We have some form of return address, so this is either the
* old diskless netboot code, or the new uniform code. That can
- * be detected by looking at the 5th argument, it if is 0 we
- * we are being booted by the new unifrom boot code.
+ * be detected by looking at the 5th argument, if it is 0
+ * we are being booted by the new uniform boot code.
*/
cmpl $0,24(%ebp)
je newboot
@@ -364,7 +422,7 @@ recover_bootinfo:
/*
* We have been loaded by the new uniform boot code.
- * Lets check the bootinfo version, and if we do not understand
+ * Let's check the bootinfo version, and if we do not understand
* it we return to the loader with a status of 1 to indicate this error
*/
newboot:
@@ -373,8 +431,11 @@ newboot:
cmpl $1,%eax /* We only understand version 1 */
je 1f
movl $1,%eax /* Return status */
- add $4, %esp /* pop recover_bootinfo's retaddr */
leave
+ /*
+ * XXX this returns to our caller's caller (as is required) since
+ * we didn't set up a frame and our caller did.
+ */
ret
1:
@@ -397,7 +458,7 @@ newboot:
movsb
2:
- /*
+ /*
* Determine the size of the boot loader's copy of the bootinfo
* struct. This is impossible to do properly because old versions
* of the struct don't contain a size field and there are 2 old
@@ -409,7 +470,7 @@ newboot:
movl BI_SIZE(%ebx),%ecx
got_bi_size:
- /*
+ /*
* Copy the common part of the bootinfo struct
*/
movl %ebx,%esi
@@ -428,7 +489,7 @@ got_common_bi_size:
*/
movl BI_NFS_DISKLESS(%ebx),%esi
cmpl $0,%esi
- je 2f
+ je olddiskboot
lea _nfs_diskless-KERNBASE,%edi
movl $NFSDISKLESS_SIZE,%ecx
cld
@@ -540,9 +601,9 @@ identify_cpu:
andb $~CCR0_NC0,%al
#ifndef CYRIX_CACHE_REALLY_WORKS
orb $(CCR0_NC1|CCR0_BARB),%al
-#else /* !CYRIX_CACHE_REALLY_WORKS */
+#else /* CYRIX_CACHE_REALLY_WORKS */
orb $CCR0_NC1,%al
-#endif /* CYRIX_CACHE_REALLY_WORKS */
+#endif /* !CYRIX_CACHE_REALLY_WORKS */
movb %al,%ah
movb $CCR0,%al
outb %al,$0x22
@@ -573,7 +634,7 @@ identify_cpu:
andl $~(CR0_CD|CR0_NW),%eax
movl %eax,%cr0
invd
-#endif /* CYRIX_CACHE_WORKS */
+#endif /* !CYRIX_CACHE_WORKS */
jmp 3f
1: /* Use the `cpuid' instruction. */
@@ -612,30 +673,31 @@ identify_cpu:
/**********************************************************************
*
- * Create the first page directory and it's page tables
+ * Create the first page directory and its page tables.
*
*/
create_pagetables:
-/* find end of kernel image */
+/* Find end of kernel image (rounded up to a page boundary). */
movl $R(_end),%esi
/* include symbols in "kernel image" if they are loaded and useful */
#ifdef DDB
movl R(_bootinfo+BI_ESYMTAB),%edi
testl %edi,%edi
- je 1f
+ je over_symalloc
movl %edi,%esi
movl $KERNBASE,%edi
addl %edi,R(_bootinfo+BI_SYMTAB)
addl %edi,R(_bootinfo+BI_ESYMTAB)
-1:
+over_symalloc:
#endif
- ROUND2PAGE(%esi)
+ addl $NBPG-1,%esi
+ andl $~(NBPG-1),%esi
movl %esi,R(_KERNend) /* save end of kernel */
- movl %esi,R(physfree) /* save end of kernel */
+ movl %esi,R(physfree) /* next free page is at end of kernel */
/* Allocate Kernel Page Tables */
ALLOCPAGES(NKPT)
@@ -647,13 +709,13 @@ create_pagetables:
/* Allocate UPAGES */
ALLOCPAGES(UPAGES)
- movl %esi,R(upa);
+ movl %esi,R(upa)
addl $KERNBASE, %esi
movl %esi, R(_proc0paddr)
-/* Allocate P0 Stack */
+/* Allocate proc0's page table for the UPAGES. */
ALLOCPAGES(1)
- movl %esi,R(p0s);
+ movl %esi,R(p0upt)
/* Map read-only from zero to the end of the kernel text section */
movl R(_KPTphys), %esi
@@ -662,17 +724,23 @@ create_pagetables:
shrl $PGSHIFT,%ecx
movl $PG_V|PG_KR,%eax
movl %esi, %ebx
+#ifdef BDE_DEBUGGER
+/* If the debugger is present, actually map everything read-write. */
+ cmpl $0,R(_bdb_exists)
+ jne map_read_write
+#endif
fillkpt
/* Map read-write, data, bss and symbols */
- andl $PG_FRAME,%eax
+map_read_write:
+ andl $PG_FRAME,%eax
movl R(_KERNend),%ecx
subl %eax,%ecx
shrl $PGSHIFT,%ecx
orl $PG_V|PG_KW,%eax
fillkpt
-/* Map PD */
+/* Map page directory. */
movl R(_IdlePTD), %eax
movl $1, %ecx
movl %eax, %ebx
@@ -681,8 +749,8 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* Map Proc 0 kernel stack */
- movl R(p0s), %eax
+/* Map proc0's page table for the UPAGES the physical way. */
+ movl R(p0upt), %eax
movl $1, %ecx
movl %eax, %ebx
shrl $PGSHIFT-2, %ebx
@@ -690,15 +758,15 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
- movl R(p0s), %eax
+/* ... and the virtual way */
+ movl R(p0upt), %eax
movl $1, %ecx
orl $PG_V|PG_KW, %eax
movl R(_KPTphys), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* Map UPAGES */
+/* Map proc0s UPAGES the physical way */
movl R(upa), %eax
movl $UPAGES, %ecx
movl %eax, %ebx
@@ -707,16 +775,16 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
+/* ... and in the special page table for this purpose. */
movl R(upa), %eax
movl $UPAGES, %ecx
orl $PG_V|PG_KW, %eax
- movl R(p0s), %ebx
+ movl R(p0upt), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* and a pde entry too */
- movl R(p0s), %eax
+/* and put the page table in the pde. */
+ movl R(p0upt), %eax
movl R(_IdlePTD), %esi
orl $PG_V|PG_KW,%eax
movl %eax,KSTKPTDI*PDESIZE(%esi)
@@ -727,10 +795,13 @@ create_pagetables:
movl $ISA_HOLE_LENGTH>>PGSHIFT, %ecx
movl $ISA_HOLE_START, %eax
movl %eax, %ebx
+/* XXX 2 is magic for log2(PTESIZE). */
shrl $PGSHIFT-2, %ebx
addl R(_KPTphys), %ebx
+/* XXX could load %eax directly with $ISA_HOLE_START|PG_V|PG_KW_PG_N. */
orl $PG_V|PG_KW|PG_N, %eax
fillkpt
+/* XXX could load %eax directly with $ISA_HOLE_START+KERNBASE. */
movl $ISA_HOLE_START, %eax
addl $KERNBASE, %eax
movl %eax, R(_atdevbase)
@@ -756,3 +827,83 @@ create_pagetables:
movl %eax,PTDPTDI*PDESIZE(%esi)
ret
+
+#ifdef BDE_DEBUGGER
+bdb_prepare_paging:
+ cmpl $0,R(_bdb_exists)
+ je bdb_prepare_paging_exit
+
+ subl $6,%esp
+
+ /*
+ * Copy and convert debugger entries from the bootstrap gdt and idt
+ * to the kernel gdt and idt. Everything is still in low memory.
+ * Tracing continues to work after paging is enabled because the
+ * low memory addresses remain valid until everything is relocated.
+ * However, tracing through the setidt() that initializes the trace
+ * trap will crash.
+ */
+ sgdt (%esp)
+ movl 2(%esp),%esi /* base address of bootstrap gdt */
+ movl $R(_gdt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel gdt */
+ movl $8*18/4,%ecx
+ cld
+ rep /* copy gdt */
+ movsl
+ movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */
+ movb $0x92,-8+5(%edi)
+ lgdt (%esp)
+
+ sidt (%esp)
+ movl 2(%esp),%esi /* base address of current idt */
+ movl 8+4(%esi),%eax /* convert dbg descriptor to ... */
+ movw 8(%esi),%ax
+ movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */
+ movl 8+2(%esi),%eax
+ movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */
+ movl 24+4(%esi),%eax /* same for bpt descriptor */
+ movw 24(%esi),%ax
+ movl %eax,R(bdb_bpt_ljmp+1)
+ movl 24+2(%esi),%eax
+ movw %ax,R(bdb_bpt_ljmp+5)
+ movl $R(_idt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel idt */
+ movl $8*4/4,%ecx
+ cld
+ rep /* copy idt */
+ movsl
+ lidt (%esp)
+
+ addl $6,%esp
+
+bdb_prepare_paging_exit:
+ ret
+
+/* Relocate debugger gdt entries and gdt and idt pointers. */
+bdb_commit_paging:
+ cmpl $0,_bdb_exists
+ je bdb_commit_paging_exit
+
+ movl $_gdt+8*9,%eax /* adjust slots 9-17 */
+ movl $9,%ecx
+reloc_gdt:
+ movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */
+ addl $8,%eax /* now KERNBASE>>24 */
+ loop reloc_gdt
+
+ subl $6,%esp
+ sgdt (%esp)
+ addl $KERNBASE,2(%esp)
+ lgdt (%esp)
+ sidt (%esp)
+ addl $KERNBASE,2(%esp)
+ lidt (%esp)
+ addl $6,%esp
+
+ int $3
+
+bdb_commit_paging_exit:
+ ret
+
+#endif /* BDE_DEBUGGER */
diff --git a/sys/i386/i386/locore.s b/sys/i386/i386/locore.s
index 0b7a78990815..fbbb9261a7ba 100644
--- a/sys/i386/i386/locore.s
+++ b/sys/i386/i386/locore.s
@@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)locore.s 7.3 (Berkeley) 5/13/91
- * $Id: locore.s,v 1.65 1996/04/26 13:47:37 phk Exp $
+ * $Id: locore.s,v 1.66 1996/04/26 22:26:45 bde Exp $
*
* originally from: locore.s, by William F. Jolitz
*
@@ -92,7 +92,7 @@
/*
* Access to each processes kernel stack is via a region of
- * per-process address space (at the beginning), immediatly above
+ * per-process address space (at the beginning), immediately above
* the user process stack.
*/
.set _kstack,USRSTACK
@@ -122,9 +122,9 @@ _bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */
_atdevbase: .long 0 /* location of start of iomem in virtual */
_KERNend: .long 0 /* phys addr end of kernel (just after bss) */
-physfree: .long 0 /* phys addr end of kernel (just after bss) */
-upa: .long 0 /* phys addr end of kernel (just after bss) */
-p0s: .long 0 /* phys addr end of kernel (just after bss) */
+physfree: .long 0 /* phys addr of next free page */
+upa: .long 0 /* phys addr of proc0's UPAGES */
+p0upt: .long 0 /* phys addr of proc0's UPAGES page table */
.globl _IdlePTD
_IdlePTD: .long 0 /* phys addr of kernel PTD */
@@ -134,6 +134,11 @@ _KPTphys: .long 0 /* phys addr of kernel page tables */
.globl _proc0paddr
_proc0paddr: .long 0 /* address of proc 0 address space */
+#ifdef BDE_DEBUGGER
+ .globl _bdb_exists /* flag to indicate BDE debugger is present */
+_bdb_exists: .long 0
+#endif
+
/**********************************************************************
*
@@ -143,8 +148,6 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
#define R(foo) ((foo)-KERNBASE)
-#define ROUND2PAGE(foo) addl $NBPG-1, foo; andl $~(NBPG-1), foo
-
#define ALLOCPAGES(foo) \
movl R(physfree), %esi ; \
movl $((foo)*NBPG), %eax ; \
@@ -153,7 +156,9 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
movl %esi, %edi ; \
movl $((foo)*NBPG),%ecx ; \
xorl %eax,%eax ; \
- cld ; rep ; stosb
+ cld ; \
+ rep ; \
+ stosb
/*
* fillkpt
@@ -165,7 +170,7 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
1: movl %eax,(%ebx) ; \
addl $NBPG,%eax ; /* increment physical address */ \
addl $4,%ebx ; /* next pte */ \
- loop 1b ;
+ loop 1b
.text
/**********************************************************************
@@ -175,43 +180,90 @@ _proc0paddr: .long 0 /* address of proc 0 address space */
*/
NON_GPROF_ENTRY(btext)
+#ifdef BDE_DEBUGGER
+#ifdef BIOS_STEALS_3K
+ cmpl $0x0375c339,0x95504
+#else
+ cmpl $0x0375c339,0x96104 /* XXX - debugger signature */
+#endif
+ jne 1f
+ movb $1,R(_bdb_exists)
+1:
+#endif
+
/* Tell the bios to warmboot next time */
movw $0x1234,0x472
-/* Set up a real frame, some day we may be doing returns */
+/* Set up a real frame in case the double return in newboot is executed. */
pushl %ebp
movl %esp, %ebp
/* Don't trust what the BIOS gives for eflags. */
pushl $PSL_KERNEL
popfl
- mov %ds, %ax /* ... or segment registers */
- mov %ax, %es
+
+/*
+ * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap
+ * to set %cs, %ds, %es and %ss.
+ */
+ mov %ds, %ax
mov %ax, %fs
mov %ax, %gs
call recover_bootinfo
-/* get onto a stack we know the size of */
+/* Get onto a stack that we can trust. */
+/*
+ * XXX this step is delayed in case recover_bootinfo needs to return via
+ * the old stack, but it need not be, since recover_bootinfo actually
+ * returns via the old frame.
+ */
movl $R(tmpstk),%esp
- mov %ds, %ax
- mov %ax, %ss
call identify_cpu
/* clear bss */
+/*
+ * XXX this should be done a little earlier. (bde)
+ *
+ * XXX we don't check that there is memory for our bss or page tables
+ * before using it. (bde)
+ *
+ * XXX the boot program somewhat bogusly clears the bss. We still have
+ * to do it in case we were unzipped by kzipboot. Then the boot program
+ * only clears kzipboot's bss.
+ *
+ * XXX the gdt and idt are still somewhere in the boot program. We
+ * depend on the convention that the boot program is below 1MB and we
+ * are above 1MB to keep the gdt and idt away from the bss and page
+ * tables. The idT is only used if BDE_DEBUGGER is enabled.
+ */
movl $R(_end),%ecx
movl $R(_edata),%edi
subl %edi,%ecx
xorl %eax,%eax
- cld ; rep ; stosb
+ cld
+ rep
+ stosb
#if NAPM > 0
- call _apm_setup /* ... in i386/apm/apm_setup.s */
-#endif /* NAPM */
+/*
+ * XXX it's not clear that APM can live in the current environonment.
+ * Only pc-relative addressing works.
+ */
+ call _apm_setup
+#endif
call create_pagetables
+#ifdef BDE_DEBUGGER
+/*
+ * Adjust as much as possible for paging before enabling paging so that the
+ * adjustments can be traced.
+ */
+ call bdb_prepare_paging
+#endif
+
/* Now enable paging */
movl R(_IdlePTD), %eax
movl %eax,%cr3 /* load ptd addr into mmu */
@@ -219,7 +271,16 @@ NON_GPROF_ENTRY(btext)
orl $CR0_PE|CR0_PG,%eax /* enable paging */
movl %eax,%cr0 /* and let's page NOW! */
- pushl $begin /* jump to high mem */
+#ifdef BDE_DEBUGGER
+/*
+ * Complete the adjustments for paging so that we can keep tracing through
+ * initi386() after the low (physical) addresses for the gdt and idT become
+ * invalid.
+ */
+ call bdb_commit_paging
+#endif
+
+ pushl $begin /* jump to high virtualized address */
ret
/* now running relocated at KERNBASE where the system is linked to run */
@@ -232,10 +293,6 @@ begin:
movl _IdlePTD, %esi
movl %esi,PCB_CR3(%eax)
- /*
- * Prepare "first" - physical address of first available page
- * after the kernel+pdir+upages+p0stack+page tables
- */
movl physfree, %esi
pushl %esi /* value of first for init386(first) */
call _init386 /* wire 386 chip for unix operation */
@@ -267,12 +324,12 @@ begin:
movl %cr0,%eax /* get control word */
orl $CR0_WP|CR0_AM,%eax /* enable i486 features */
movl %eax,%cr0 /* and do it */
+1:
#endif
/*
* on return from main(), we are process 1
* set up address space and stack so that we can 'return' to user mode
*/
-1:
movl __ucodesel,%eax
movl __udatasel,%ecx
@@ -303,6 +360,7 @@ _esigcode:
.globl _szsigcode
_szsigcode:
.long _esigcode-_sigcode
+ .text
/**********************************************************************
*
@@ -349,8 +407,8 @@ recover_bootinfo:
/*
* We have some form of return address, so this is either the
* old diskless netboot code, or the new uniform code. That can
- * be detected by looking at the 5th argument, it if is 0 we
- * we are being booted by the new unifrom boot code.
+ * be detected by looking at the 5th argument, if it is 0
+ * we are being booted by the new uniform boot code.
*/
cmpl $0,24(%ebp)
je newboot
@@ -364,7 +422,7 @@ recover_bootinfo:
/*
* We have been loaded by the new uniform boot code.
- * Lets check the bootinfo version, and if we do not understand
+ * Let's check the bootinfo version, and if we do not understand
* it we return to the loader with a status of 1 to indicate this error
*/
newboot:
@@ -373,8 +431,11 @@ newboot:
cmpl $1,%eax /* We only understand version 1 */
je 1f
movl $1,%eax /* Return status */
- add $4, %esp /* pop recover_bootinfo's retaddr */
leave
+ /*
+ * XXX this returns to our caller's caller (as is required) since
+ * we didn't set up a frame and our caller did.
+ */
ret
1:
@@ -397,7 +458,7 @@ newboot:
movsb
2:
- /*
+ /*
* Determine the size of the boot loader's copy of the bootinfo
* struct. This is impossible to do properly because old versions
* of the struct don't contain a size field and there are 2 old
@@ -409,7 +470,7 @@ newboot:
movl BI_SIZE(%ebx),%ecx
got_bi_size:
- /*
+ /*
* Copy the common part of the bootinfo struct
*/
movl %ebx,%esi
@@ -428,7 +489,7 @@ got_common_bi_size:
*/
movl BI_NFS_DISKLESS(%ebx),%esi
cmpl $0,%esi
- je 2f
+ je olddiskboot
lea _nfs_diskless-KERNBASE,%edi
movl $NFSDISKLESS_SIZE,%ecx
cld
@@ -540,9 +601,9 @@ identify_cpu:
andb $~CCR0_NC0,%al
#ifndef CYRIX_CACHE_REALLY_WORKS
orb $(CCR0_NC1|CCR0_BARB),%al
-#else /* !CYRIX_CACHE_REALLY_WORKS */
+#else /* CYRIX_CACHE_REALLY_WORKS */
orb $CCR0_NC1,%al
-#endif /* CYRIX_CACHE_REALLY_WORKS */
+#endif /* !CYRIX_CACHE_REALLY_WORKS */
movb %al,%ah
movb $CCR0,%al
outb %al,$0x22
@@ -573,7 +634,7 @@ identify_cpu:
andl $~(CR0_CD|CR0_NW),%eax
movl %eax,%cr0
invd
-#endif /* CYRIX_CACHE_WORKS */
+#endif /* !CYRIX_CACHE_WORKS */
jmp 3f
1: /* Use the `cpuid' instruction. */
@@ -612,30 +673,31 @@ identify_cpu:
/**********************************************************************
*
- * Create the first page directory and it's page tables
+ * Create the first page directory and its page tables.
*
*/
create_pagetables:
-/* find end of kernel image */
+/* Find end of kernel image (rounded up to a page boundary). */
movl $R(_end),%esi
/* include symbols in "kernel image" if they are loaded and useful */
#ifdef DDB
movl R(_bootinfo+BI_ESYMTAB),%edi
testl %edi,%edi
- je 1f
+ je over_symalloc
movl %edi,%esi
movl $KERNBASE,%edi
addl %edi,R(_bootinfo+BI_SYMTAB)
addl %edi,R(_bootinfo+BI_ESYMTAB)
-1:
+over_symalloc:
#endif
- ROUND2PAGE(%esi)
+ addl $NBPG-1,%esi
+ andl $~(NBPG-1),%esi
movl %esi,R(_KERNend) /* save end of kernel */
- movl %esi,R(physfree) /* save end of kernel */
+ movl %esi,R(physfree) /* next free page is at end of kernel */
/* Allocate Kernel Page Tables */
ALLOCPAGES(NKPT)
@@ -647,13 +709,13 @@ create_pagetables:
/* Allocate UPAGES */
ALLOCPAGES(UPAGES)
- movl %esi,R(upa);
+ movl %esi,R(upa)
addl $KERNBASE, %esi
movl %esi, R(_proc0paddr)
-/* Allocate P0 Stack */
+/* Allocate proc0's page table for the UPAGES. */
ALLOCPAGES(1)
- movl %esi,R(p0s);
+ movl %esi,R(p0upt)
/* Map read-only from zero to the end of the kernel text section */
movl R(_KPTphys), %esi
@@ -662,17 +724,23 @@ create_pagetables:
shrl $PGSHIFT,%ecx
movl $PG_V|PG_KR,%eax
movl %esi, %ebx
+#ifdef BDE_DEBUGGER
+/* If the debugger is present, actually map everything read-write. */
+ cmpl $0,R(_bdb_exists)
+ jne map_read_write
+#endif
fillkpt
/* Map read-write, data, bss and symbols */
- andl $PG_FRAME,%eax
+map_read_write:
+ andl $PG_FRAME,%eax
movl R(_KERNend),%ecx
subl %eax,%ecx
shrl $PGSHIFT,%ecx
orl $PG_V|PG_KW,%eax
fillkpt
-/* Map PD */
+/* Map page directory. */
movl R(_IdlePTD), %eax
movl $1, %ecx
movl %eax, %ebx
@@ -681,8 +749,8 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* Map Proc 0 kernel stack */
- movl R(p0s), %eax
+/* Map proc0's page table for the UPAGES the physical way. */
+ movl R(p0upt), %eax
movl $1, %ecx
movl %eax, %ebx
shrl $PGSHIFT-2, %ebx
@@ -690,15 +758,15 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
- movl R(p0s), %eax
+/* ... and the virtual way */
+ movl R(p0upt), %eax
movl $1, %ecx
orl $PG_V|PG_KW, %eax
movl R(_KPTphys), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* Map UPAGES */
+/* Map proc0s UPAGES the physical way */
movl R(upa), %eax
movl $UPAGES, %ecx
movl %eax, %ebx
@@ -707,16 +775,16 @@ create_pagetables:
orl $PG_V|PG_KW, %eax
fillkpt
-/* ... also in user page table page */
+/* ... and in the special page table for this purpose. */
movl R(upa), %eax
movl $UPAGES, %ecx
orl $PG_V|PG_KW, %eax
- movl R(p0s), %ebx
+ movl R(p0upt), %ebx
addl $(KSTKPTEOFF * PTESIZE), %ebx
fillkpt
-/* and a pde entry too */
- movl R(p0s), %eax
+/* and put the page table in the pde. */
+ movl R(p0upt), %eax
movl R(_IdlePTD), %esi
orl $PG_V|PG_KW,%eax
movl %eax,KSTKPTDI*PDESIZE(%esi)
@@ -727,10 +795,13 @@ create_pagetables:
movl $ISA_HOLE_LENGTH>>PGSHIFT, %ecx
movl $ISA_HOLE_START, %eax
movl %eax, %ebx
+/* XXX 2 is magic for log2(PTESIZE). */
shrl $PGSHIFT-2, %ebx
addl R(_KPTphys), %ebx
+/* XXX could load %eax directly with $ISA_HOLE_START|PG_V|PG_KW_PG_N. */
orl $PG_V|PG_KW|PG_N, %eax
fillkpt
+/* XXX could load %eax directly with $ISA_HOLE_START+KERNBASE. */
movl $ISA_HOLE_START, %eax
addl $KERNBASE, %eax
movl %eax, R(_atdevbase)
@@ -756,3 +827,83 @@ create_pagetables:
movl %eax,PTDPTDI*PDESIZE(%esi)
ret
+
+#ifdef BDE_DEBUGGER
+bdb_prepare_paging:
+ cmpl $0,R(_bdb_exists)
+ je bdb_prepare_paging_exit
+
+ subl $6,%esp
+
+ /*
+ * Copy and convert debugger entries from the bootstrap gdt and idt
+ * to the kernel gdt and idt. Everything is still in low memory.
+ * Tracing continues to work after paging is enabled because the
+ * low memory addresses remain valid until everything is relocated.
+ * However, tracing through the setidt() that initializes the trace
+ * trap will crash.
+ */
+ sgdt (%esp)
+ movl 2(%esp),%esi /* base address of bootstrap gdt */
+ movl $R(_gdt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel gdt */
+ movl $8*18/4,%ecx
+ cld
+ rep /* copy gdt */
+ movsl
+ movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */
+ movb $0x92,-8+5(%edi)
+ lgdt (%esp)
+
+ sidt (%esp)
+ movl 2(%esp),%esi /* base address of current idt */
+ movl 8+4(%esi),%eax /* convert dbg descriptor to ... */
+ movw 8(%esi),%ax
+ movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */
+ movl 8+2(%esi),%eax
+ movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */
+ movl 24+4(%esi),%eax /* same for bpt descriptor */
+ movw 24(%esi),%ax
+ movl %eax,R(bdb_bpt_ljmp+1)
+ movl 24+2(%esi),%eax
+ movw %ax,R(bdb_bpt_ljmp+5)
+ movl $R(_idt),%edi
+ movl %edi,2(%esp) /* prepare to load kernel idt */
+ movl $8*4/4,%ecx
+ cld
+ rep /* copy idt */
+ movsl
+ lidt (%esp)
+
+ addl $6,%esp
+
+bdb_prepare_paging_exit:
+ ret
+
+/* Relocate debugger gdt entries and gdt and idt pointers. */
+bdb_commit_paging:
+ cmpl $0,_bdb_exists
+ je bdb_commit_paging_exit
+
+ movl $_gdt+8*9,%eax /* adjust slots 9-17 */
+ movl $9,%ecx
+reloc_gdt:
+ movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */
+ addl $8,%eax /* now KERNBASE>>24 */
+ loop reloc_gdt
+
+ subl $6,%esp
+ sgdt (%esp)
+ addl $KERNBASE,2(%esp)
+ lgdt (%esp)
+ sidt (%esp)
+ addl $KERNBASE,2(%esp)
+ lidt (%esp)
+ addl $6,%esp
+
+ int $3
+
+bdb_commit_paging_exit:
+ ret
+
+#endif /* BDE_DEBUGGER */
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-02 15:28:13 +0000