Module Name: src
Committed By: maxv
Date: Fri May 13 14:03:00 UTC 2016
Modified Files:
src/sys/arch/i386/i386: locore.S
Log Message:
Bring some amd64 swag. No functional changes.
To generate a diff of this commit:
cvs rdiff -u -r1.116 -r1.117 src/sys/arch/i386/i386/locore.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/i386/i386/locore.S
diff -u src/sys/arch/i386/i386/locore.S:1.116 src/sys/arch/i386/i386/locore.S:1.117
--- src/sys/arch/i386/i386/locore.S:1.116 Thu May 12 06:45:16 2016
+++ src/sys/arch/i386/i386/locore.S Fri May 13 14:03:00 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.S,v 1.116 2016/05/12 06:45:16 maxv Exp $ */
+/* $NetBSD: locore.S,v 1.117 2016/05/13 14:03:00 maxv Exp $ */
/*
* Copyright-o-rama!
@@ -128,7 +128,7 @@
*/
#include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: locore.S,v 1.116 2016/05/12 06:45:16 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: locore.S,v 1.117 2016/05/13 14:03:00 maxv Exp $");
#include "opt_compat_oldboot.h"
#include "opt_copy_symtab.h"
@@ -340,10 +340,13 @@ _C_LABEL(Multiboot_Header):
1:
/*
* At this point, we know that a NetBSD-specific boot loader
- * booted this kernel. The stack carries the following parameters:
- * (boothowto, [bootdev], bootinfo, esym, biosextmem, biosbasemem),
- * 4 bytes each.
+ * booted this kernel.
+ *
+ * Load parameters from the stack (32 bits):
+ * boothowto, [bootdev], bootinfo, esym, biosextmem, biosbasemem
+ * We are not interested in 'bootdev'.
*/
+
addl $4,%esp /* Discard return address to boot loader */
call _C_LABEL(native_loader)
addl $24,%esp
@@ -537,22 +540,43 @@ try586: /* Use the `cpuid' instruction.
movl $_RELOC(tmpstk),%esp
/*
- * Virtual address space of kernel, without PAE. The page dir is 1 page long.
+ * There are two different layouts possible, depending on whether PAE is
+ * enabled or not.
*
- * text | data | bss | [syms] | [blobs] | page dir | proc0 kstack | L1 ptp
- * 0 1 2 3
+ * If PAE is not enabled, there are two levels of pages: PD -> PT. They will
+ * be referred to as: L2 -> L1. L2 is 1 page long. The BOOTSTRAP TABLES have
+ * the following layout:
+ * +-----+------------+----+
+ * | L2 -> PROC0 STK -> L1 |
+ * +-----+------------+----+
+ *
+ * If PAE is enabled, there are three levels of pages: PDP -> PD -> PT. They
+ * will be referred to as: L3 -> L2 -> L1. L3 is 1 page long, L2 is 4 page
+ * long. The BOOTSTRAP TABLES have the following layout:
+ * +-----+-----+------------+----+
+ * | L3 -> L2 -> PROC0 STK -> L1 |
+ * +-----+-----+------------+----+
+ *
+ * Virtual address space of the kernel in both cases:
+ * +------+--------+------+-----+--------+---------------------+-----------
+ * | TEXT | RODATA | DATA | BSS | [SYMS] | [PRELOADED MODULES] | BOOTSTRAP
+ * +------+--------+------+-----+--------+---------------------+-----------
+ * (1) (2) (3)
+ *
+ * -------+------------+
+ * TABLES | ISA IO MEM |
+ * -------+------------+
+ * (4)
*
- * Virtual address space of kernel, with PAE. We need 4 pages for the page dir
- * and 1 page for the L3.
- * text | data | bss | [syms] | [blobs] | L3 | page dir | proc0 kstack | L1 ptp
- * 0 1 5 6 7
+ * PROC0 STK is obviously not linked as a page level. It just happens to be
+ * caught between L2 and L1.
*/
- /* Find end of kernel image. */
+ /* Find end of kernel image; brings us on (1). */
movl $RELOC(end),%edi
#if (NKSYMS || defined(DDB) || defined(MODULAR)) && !defined(makeoptions_COPY_SYMTAB)
- /* Save the symbols (if loaded). */
+ /* Save the symbols (if loaded); brinds us on (2). */
movl RELOC(esym),%eax
testl %eax,%eax
jz 1f
@@ -561,14 +585,15 @@ try586: /* Use the `cpuid' instruction.
1:
#endif
- /* Skip over any modules/blobs. */
+ /* Skip over any modules/blobs; brings us on (3). */
movl RELOC(eblob),%eax
testl %eax,%eax
jz 1f
subl $KERNBASE,%eax
movl %eax,%edi
1:
- /* Compute sizes */
+
+ /* We are on (3). Align up for BOOTSTRAP TABLES. */
movl %edi,%esi
addl $PGOFSET,%esi
andl $~PGOFSET,%esi
@@ -577,20 +602,20 @@ try586: /* Use the `cpuid' instruction.
movl %esi,%eax
addl $~L2_FRAME,%eax
shrl $L2_SHIFT,%eax
- incl %eax /* one more ptp for VAs stolen by bootstrap */
+ incl %eax /* one more PTP for VAs stolen by bootstrap */
1: movl %eax,RELOC(nkptp)+1*4
/* tablesize = (PDP_SIZE + UPAGES + nkptp) << PGSHIFT; */
addl $(PDP_SIZE+UPAGES),%eax
#ifdef PAE
- incl %eax /* one more page for the L3 PD */
+ incl %eax /* one more page for L3 */
shll $PGSHIFT+1,%eax /* PTP tables are twice larger with PAE */
#else
shll $PGSHIFT,%eax
#endif
movl %eax,RELOC(tablesize)
- /* ensure that nkptp covers bootstrap tables */
+ /* Ensure that nkptp covers BOOTSTRAP TABLES. */
addl %esi,%eax
addl $~L2_FRAME,%eax
shrl $L2_SHIFT,%eax
@@ -598,36 +623,35 @@ try586: /* Use the `cpuid' instruction.
cmpl %eax,RELOC(nkptp)+1*4
jnz 1b
- /* Clear tables */
+ /* Now, zero out the BOOTSTRAP TABLES (before filling them in). */
movl %esi,%edi
xorl %eax,%eax
cld
movl RELOC(tablesize),%ecx
shrl $2,%ecx
rep
- stosl
-
- leal (PROC0_PTP1_OFF)(%esi), %ebx
+ stosl /* copy eax -> edi */
/*
- * Build initial page tables.
+ * Build the page tables and levels. We go from L1 to L2/L3, and link the levels
+ * together. Note: RELOC computes &addr - KERNBASE in 32 bits; the value can't
+ * be > 4G, or we can't deal with it anyway, since we are in 32bit mode.
*/
/*
- * Compute &__rodata_start - KERNBASE. This can't be > 4G,
- * or we can't deal with it anyway, since we can't load it in
- * 32 bit mode. So use the bottom 32 bits.
+ * Build L1.
*/
+ leal (PROC0_PTP1_OFF)(%esi),%ebx
+
+ /* Compute &__rodata_start - KERNBASE. */
movl $RELOC(__rodata_start),%edx
andl $~PGOFSET,%edx
- /*
- * Skip the first MB.
- */
+ /* Skip the first MB. */
movl $_RELOC(KERNTEXTOFF),%eax
movl %eax,%ecx
- shrl $(PGSHIFT-2),%ecx /* ((n >> PGSHIFT) << 2) for # pdes */
+ shrl $(PGSHIFT-2),%ecx /* ((n >> PGSHIFT) << 2) for # PDEs */
#ifdef PAE
- shll $1,%ecx /* pdes are twice larger with PAE */
+ shll $1,%ecx /* PDEs are twice larger with PAE */
#endif
addl %ecx,%ebx
@@ -651,32 +675,33 @@ try586: /* Use the `cpuid' instruction.
movl $(IOM_SIZE>>PGSHIFT),%ecx
fillkpt
-/*
- * Construct a page table directory.
- */
- /* Set up top level entries for identity mapping */
+ /*
+ * Build L2 for identity mapping. Linked to L1.
+ */
leal (PROC0_PDIR_OFF)(%esi),%ebx
leal (PROC0_PTP1_OFF)(%esi),%eax
- orl $(PG_V|PG_KW), %eax
+ orl $(PG_V|PG_KW),%eax
movl RELOC(nkptp)+1*4,%ecx
fillkpt
- /* Set up top level entries for actual kernel mapping */
- leal (PROC0_PDIR_OFF + L2_SLOT_KERNBASE*PDE_SIZE)(%esi),%ebx
+ /* Set up L2 entries for actual kernel mapping */
+ leal (PROC0_PDIR_OFF + L2_SLOT_KERNBASE * PDE_SIZE)(%esi),%ebx
leal (PROC0_PTP1_OFF)(%esi),%eax
- orl $(PG_V|PG_KW), %eax
+ orl $(PG_V|PG_KW),%eax
movl RELOC(nkptp)+1*4,%ecx
fillkpt
/* Install a PDE recursively mapping page directory as a page table! */
- leal (PROC0_PDIR_OFF + PDIR_SLOT_PTE*PDE_SIZE)(%esi),%ebx
+ leal (PROC0_PDIR_OFF + PDIR_SLOT_PTE * PDE_SIZE)(%esi),%ebx
leal (PROC0_PDIR_OFF)(%esi),%eax
orl $(PG_V|PG_KW),%eax
movl $PDP_SIZE,%ecx
fillkpt
#ifdef PAE
- /* Fill in proc0 L3 page with entries pointing to the page dirs */
+ /*
+ * Build L3. Linked to L2.
+ */
leal (PROC0_L3_OFF)(%esi),%ebx
leal (PROC0_PDIR_OFF)(%esi),%eax
orl $(PG_V),%eax
@@ -689,16 +714,16 @@ try586: /* Use the `cpuid' instruction.
movl %eax,%cr4
#endif
- /* Save phys. addr of PDP, for libkvm. */
+ /* Save physical address of L2. */
leal (PROC0_PDIR_OFF)(%esi),%eax
movl %eax,RELOC(PDPpaddr)
/*
* Startup checklist:
- * 1. Load %cr3 with pointer to PDIR (or L3 PD page for PAE).
+ * 1. Load %cr3 with pointer to L2 (or L3 for PAE).
*/
- movl %esi,%eax /* phys address of PTD in proc0 */
- movl %eax,%cr3 /* load PTD addr into MMU */
+ movl %esi,%eax
+ movl %eax,%cr3
/*
* 2. Enable paging and the rest of it.
@@ -712,9 +737,8 @@ try586: /* Use the `cpuid' instruction.
begin:
/*
- * We have arrived.
- * There's no need anymore for the identity mapping in low
- * memory, remove it.
+ * We have arrived. There's no need anymore for the identity mapping in
+ * low memory, remove it.
*/
movl _C_LABEL(nkptp)+1*4,%ecx
leal (PROC0_PDIR_OFF)(%esi),%ebx /* old, phys address of PDIR */
