page.c

CIRRUS 93XX系列windows mobile 6.0 BSP

#include <windows.h>
#include <memorymap.h>

#define UNCACHED                  0x00000000
#define WRITE_THROUGH       0x00000008
#define WRITE_BACK              0x0000000C

// Level one descriptors.

#define SECTION_HEADER          0x00000C12
#define COURSE_PAGETABLE    0x00000011
#define INVALID_DESCRIPTOR  0x00000000


// Level two descriptors.
#define SMALL_PAGE                   0x00000FF2

/******************************************************************************
; PhysAddrStart = Physical start of memory to map. 
; PhysAddrEnd   = Physical end of memory to map.
; DescrAttr     = Descriptor attributes.
; EntryReg      = Register which is a pointer to the current page table entry 
******************************************************************************/

DWORD   CreateSectionEntry(  DWORD PhysAddrStart,  DWORD dwLen, DWORD  DescrAttr , DWORD dwAddr)
{
	DWORD * pAddr= (DWORD*) dwAddr;
	DWORD i;

	for( i=0; i< dwLen; i+=0x100000 , PhysAddrStart+= 0x100000 ){

		 *pAddr++=PhysAddrStart | DescrAttr;
	}
	return (DWORD) pAddr;
}

/*****************************************************************************
;
; Creates a entry for a small level 2 table.
;
; PhysAddrStart = Physical start of memory to map. 
; PhysAddrEnd   = Physical end of memory to map.
; DescrAttr     = Descriptor attributes.
; EntryReg      = Register which is a pointer to the current page table entry 
;*****************************************************************************/

DWORD   CreateCourseEntry(    DWORD PhysAddrStart, DWORD  dwLen, DWORD  DescrAttr , DWORD dwAddr)
{
	DWORD * pAddr= (DWORD*) dwAddr;
	DWORD i;

	for( i=0; i< dwLen; i+=0x1000, PhysAddrStart+= 0x1000 ){

		*pAddr++=PhysAddrStart | DescrAttr;
	}
	return (DWORD) pAddr;
}

/*****************************************************************************
;
; The function to setup the MMU.
;
; r4 - Current Pagetable pointer. Virtual Address.
; r5 - Start of Pagetable (Physical Address)
; r6 - Level 2 Course Page Table.
;*****************************************************************************/
void   PageTableSetup( DWORD dwPageStart )
{
       DWORD dwAddress=dwPageStart ;
	   DWORD dwSize=0;

	   //a system must take at least one piece of SDRAM
        dwAddress=CreateSectionEntry( PHYSICAL_ADDR_SDRAM_MAIN, SDRAM_MAIN_BLOCK_SIZE,
			                                               (SECTION_HEADER | WRITE_BACK)  , dwAddress); 
		dwSize=SDRAM_MAIN_BLOCK_SIZE;

#if ( (SIZE_SDRAM_MAIN/SDRAM_MAIN_BLOCK_SIZE ) >1 )

        dwAddress=CreateSectionEntry( PHYSICAL_ADDR_SDRAM_MAIN_BLOCK1, SDRAM_MAIN_BLOCK_SIZE,
			                                               (SECTION_HEADER | WRITE_BACK)  , dwAddress); 
		dwSize +=SDRAM_MAIN_BLOCK_SIZE;

#endif
#if ( (SIZE_SDRAM_MAIN/SDRAM_MAIN_BLOCK_SIZE ) >2 )

        dwAddress=CreateSectionEntry( PHYSICAL_ADDR_SDRAM_MAIN_BLOCK2, SDRAM_MAIN_BLOCK_SIZE,
			                                               (SECTION_HEADER | WRITE_BACK)  , dwAddress); 
		dwSize +=SDRAM_MAIN_BLOCK_SIZE;

#endif
#if ( (SIZE_SDRAM_MAIN/SDRAM_MAIN_BLOCK_SIZE ) >3 )

        dwAddress=CreateSectionEntry( PHYSICAL_ADDR_SDRAM_MAIN_BLOCK3, SDRAM_MAIN_BLOCK_SIZE,
			                                               (SECTION_HEADER | WRITE_BACK)  , dwAddress); 
		dwSize +=SDRAM_MAIN_BLOCK_SIZE;

#endif
       // mask from the end of the SDRAM to 0x10000000 as INVALID.
        dwAddress=CreateSectionEntry( dwSize, 0x10000000- dwSize, (INVALID_DESCRIPTOR)  , dwAddress);
        dwAddress=CreateSectionEntry(0x10000000, 0xF0000000, (SECTION_HEADER | UNCACHED) , dwAddress); 

//        dwAddress=CreateSectionEntry( 0xC0000000, 0x02000000, (SECTION_HEADER | UNCACHED)  , dwAddress); 
//        dwAddress=CreateSectionEntry( 0xC4000000, 0x02000000, (SECTION_HEADER | UNCACHED) , dwAddress); 
//        dwAddress=CreateSectionEntry( 0x04000000, 0x0C000000, (INVALID_DESCRIPTOR)        , dwAddress);
//        dwAddress=CreateSectionEntry(0x10000000, 0xF0000000, (SECTION_HEADER | UNCACHED) , dwAddress); 

		//dwAddress should be dwPageStart+0x400 here.
		*(DWORD*)dwPageStart= (dwAddress) |COURSE_PAGETABLE;

		//the first 1M bytes takes EBOOT codes, RAM and DRIVER GLOBAL,so create two level page table for these area.
        dwAddress=CreateCourseEntry(  PHYSICAL_ADDR_SDRAM_MAIN, 0x00040000, 
			                                                (SMALL_PAGE | UNCACHED)     , dwAddress); // 0x00000000, 0x0003FFFF
        dwAddress=CreateCourseEntry(  PHYSICAL_ADDR_SDRAM_MAIN+0x00040000, 0x00C00000, 
			                                                (SMALL_PAGE | WRITE_BACK) , dwAddress); // 0x00000000, 0x000FFFFF
}