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[FAST486]

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Modularize linear memory access by adding two new functions:
Fast486ReadLinearMemory and Fast486WriteLinearMemory.
Implement Fast486GetPageTableEntry.


svn path=/branches/ntvdm/; revision=60923
This commit is contained in:
Aleksandar Andrejevic 2013-11-10 22:27:24 +00:00
parent 7c036fd0f7
commit c3c7bb89c1
6 changed files with 264 additions and 146 deletions
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138
lib/fast486/common.c
View file

@ -29,19 +29,6 @@
#include <fast486.h>
#include "common.h"
/* PRIVATE FUNCTIONS **********************************************************/
static inline
ULONG
Fast486GetPageTableEntry(PFAST486_STATE State,
ULONG VirtualAddress)
{
// TODO: NOT IMPLEMENTED
UNIMPLEMENTED;
return 0;
}
/* PUBLIC FUNCTIONS ***********************************************************/
BOOLEAN
@ -54,7 +41,6 @@ Fast486ReadMemory(PFAST486_STATE State,
{
ULONG LinearAddress;
PFAST486_SEG_REG CachedDescriptor;
INT Cpl = Fast486GetCurrentPrivLevel(State);
ASSERT(SegmentReg < FAST486_NUM_SEG_REGS);
@ -108,58 +94,8 @@ Fast486ReadMemory(PFAST486_STATE State,
/* Find the linear address */
LinearAddress = CachedDescriptor->Base + Offset;
/* Check if paging is enabled */
if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
{
ULONG Page;
FAST486_PAGE_TABLE TableEntry;
for (Page = PAGE_ALIGN(LinearAddress);
Page <= PAGE_ALIGN(LinearAddress + Size - 1);
Page += PAGE_SIZE)
{
ULONG PageOffset = 0, PageLength = PAGE_SIZE;
/* Get the table entry */
TableEntry.Value = Fast486GetPageTableEntry(State, Page);
if (!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
{
/* Exception */
Fast486ExceptionWithErrorCode(State,
FAST486_EXCEPTION_PF,
TableEntry.Value & 0x07);
return FALSE;
}
/* Check if this is the first page */
if (Page == PAGE_ALIGN(LinearAddress))
{
/* Start copying from the offset from the beginning of the page */
PageOffset = PAGE_OFFSET(LinearAddress);
}
/* Check if this is the last page */
if (Page == PAGE_ALIGN(LinearAddress + Size - 1))
{
/* Copy only a part of the page */
PageLength = PAGE_OFFSET(LinearAddress + Size);
}
/* Read the memory */
State->MemReadCallback(State,
(TableEntry.Address << 12) | PageOffset,
Buffer,
PageLength);
}
}
else
{
/* Read the memory */
State->MemReadCallback(State, LinearAddress, Buffer, Size);
}
return TRUE;
/* Read from the linear address */
return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size);
}
BOOLEAN
@ -171,7 +107,6 @@ Fast486WriteMemory(PFAST486_STATE State,
{
ULONG LinearAddress;
PFAST486_SEG_REG CachedDescriptor;
INT Cpl = Fast486GetCurrentPrivLevel(State);
ASSERT(SegmentReg < FAST486_NUM_SEG_REGS);
@ -220,60 +155,8 @@ Fast486WriteMemory(PFAST486_STATE State,
/* Find the linear address */
LinearAddress = CachedDescriptor->Base + Offset;
/* Check if paging is enabled */
if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
{
ULONG Page;
FAST486_PAGE_TABLE TableEntry;
for (Page = PAGE_ALIGN(LinearAddress);
Page <= PAGE_ALIGN(LinearAddress + Size - 1);
Page += PAGE_SIZE)
{
ULONG PageOffset = 0, PageLength = PAGE_SIZE;
/* Get the table entry */
TableEntry.Value = Fast486GetPageTableEntry(State, Page);
if ((!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
|| ((State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_WP)
&& !TableEntry.Writeable))
{
/* Exception */
Fast486ExceptionWithErrorCode(State,
FAST486_EXCEPTION_PF,
TableEntry.Value & 0x07);
return FALSE;
}
/* Check if this is the first page */
if (Page == PAGE_ALIGN(LinearAddress))
{
/* Start copying from the offset from the beginning of the page */
PageOffset = PAGE_OFFSET(LinearAddress);
}
/* Check if this is the last page */
if (Page == PAGE_ALIGN(LinearAddress + Size - 1))
{
/* Copy only a part of the page */
PageLength = PAGE_OFFSET(LinearAddress + Size);
}
/* Write the memory */
State->MemWriteCallback(State,
(TableEntry.Address << 12) | PageOffset,
Buffer,
PageLength);
}
}
else
{
/* Write the memory */
State->MemWriteCallback(State, LinearAddress, Buffer, Size);
}
return TRUE;
/* Write to the linear address */
return Fast486WriteLinearMemory(State, LinearAddress, Buffer, Size);
}
BOOLEAN
@ -293,11 +176,14 @@ Fast486InterruptInternal(PFAST486_STATE State,
if (Fast486GetCurrentPrivLevel(State) > GET_SEGMENT_RPL(SegmentSelector))
{
/* Read the TSS */
// FIXME: This code is only correct when paging is disabled!!!
State->MemReadCallback(State,
State->Tss.Address,
&Tss,
sizeof(Tss));
if (!Fast486ReadLinearMemory(State,
State->Tss.Address,
&Tss,
sizeof(Tss)))
{
/* Exception occurred */
return FALSE;
}
/* Check the new (higher) privilege level */
switch (GET_SEGMENT_RPL(SegmentSelector))