OEMAddressTable 内存映射表是怎么被wince使用的（作者：wogoyixikexie@gliet）

作者：wogoyixikexie@gliet

;------------------------------------------------------------------------------

;

; File: memory_cfg.inc

;

; This file is used to define g_oalAddressTable. This table is passed to

; KernelStart to estabilish physical to virtual memory mapping. This table

; is used also in IOMEM OAL module to map between physical and virtual

; memory addresses via OALPAtoVA/OALVAtoPA functions.

;

;------------------------------------------------------------------------------

; Export Definition

EXPORT g_oalAddressTable[DATA]

;------------------------------------------------------------------------------

;

; TABLE FORMAT

; cached address, physical address, size

;------------------------------------------------------------------------------

g_oalAddressTable

DCD 0x80000000, 0x30000000, 64 ; 32 MB DRAM BANK 6

DCD 0x84000000, 0x10000000, 32 ; nGCS2: PCMCIA/PCCARD

DCD 0x86000000, 0x18000000, 32 ; 32 MB SROM(SRAM/ROM) BANK 3

DCD 0x88000000, 0x20000000, 32 ; 32 MB SROM(SRAM/ROM) BANK 4

DCD 0x8A000000, 0x28000000, 32 ; 32 MB SROM(SRAM/ROM) BANK 5

DCD 0x8C000000, 0x08000000, 32 ; 32 MB SROM(SRAM/ROM) BANK 1

DCD 0x90800000, 0x48000000, 1 ; Memory control register

DCD 0x90900000, 0x49000000, 1 ; USB Host register

DCD 0x90A00000, 0x4A000000, 1 ; Interrupt Control register

DCD 0x90B00000, 0x4B000000, 1 ; DMA control register

DCD 0x90C00000, 0x4C000000, 1 ; Clock & Power register

DCD 0x90D00000, 0x4D000000, 1 ; LCD control register

DCD 0x90E00000, 0x4E000000, 1 ; NAND flash control register

DCD 0x90F00000, 0x4F000000, 1 ; Camera control register

DCD 0x91000000, 0x50000000, 1 ; UART control register

DCD 0x91100000, 0x51000000, 1 ; PWM timer register

DCD 0x91200000, 0x52000000, 1 ; USB device register

DCD 0x91300000, 0x53000000, 1 ; Watchdog Timer register

DCD 0x91400000, 0x54000000, 1 ; IIC control register

DCD 0x91500000, 0x55000000, 1 ; IIS control register

DCD 0x91600000, 0x56000000, 1 ; I/O Port register

DCD 0x91700000, 0x57000000, 1 ; RTC control register

DCD 0x91800000, 0x58000000, 1 ; A/D convert register

DCD 0x91900000, 0x59000000, 1 ; SPI register

DCD 0x91A00000, 0x5A000000, 1 ; SD Interface register

DCD 0x92000000, 0x00000000, 32 ; 32 MB SROM(SRAM/ROM) BANK 0

DCD 0x00000000, 0x00000000, 0 ; end of table

;------------------------------------------------------------------------------

END

以前，一直不知道这个表是怎么回事，刚才偶然的机会，看见了调用他的函数

C:/WINCE500/PLATFORM/COMMON/SRC/ARM/COMMON/MEMORY/memory.c

//------------------------------------------------------------------------------

//

// File: memory.c

// 从这个代码看出ARM虚拟内存和物理内存的关系

// Memory interface routines.

//

#include <windows.h>

#include <oal_log.h>

#include <oal_memory.h>

typedef struct {

UINT32 CA; // cached virtual address

UINT32 PA; // physical address

UINT32 size; // size, in MB bytes

} OAL_ADDRESS_TABLE, *POAL_ADDRESS_TABLE;

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

//

// Function: OALPAtoVA

//

// Converts a physical address (PA) to a virtual address (VA). This routine

// uses the OEMAddressTable defined in the platform.

//

VOID* OALPAtoVA(UINT32 pa, BOOL cached)

{

OAL_ADDRESS_TABLE *pTable = g_oalAddressTable;

VOID *va = NULL;

OALMSG(OAL_MEMORY&&OAL_FUNC, (L"+OALPAtoVA(0x%x, %d)/r/n", pa, cached));

// Search the table for address range

while (pTable->size != 0) {

if (

pa >= pTable->PA &&

pa <= (pTable->PA + (pTable->size << 20) - 1)

) break; // match found 找到表中相近的内存

pTable++;

}

// If address table entry is valid compute the VA

if (pTable->size != 0) {

va = (VOID *)(pTable->CA + (pa - pTable->PA));

// If VA is uncached, set the uncached bit

if (!cached) (UINT32)va |= OAL_MEMORY_CACHE_BIT;

}

// Indicate the virtual address

OALMSG(OAL_MEMORY&&OAL_FUNC, (L"-OALPAtoVA(va = 0x%08x)/r/n", va));

return va;

}

//------------------------------------------------------------------------------

//

// Function: OALVAtoPA

//

// Converts a virtual address (VA) to a physical address (PA). This routine

// uses the OEMAddressTable defined in the platform.

//

UINT32 OALVAtoPA(VOID *pVA)

{

OAL_ADDRESS_TABLE *pTable = g_oalAddressTable;

UINT32 va = (UINT32)pVA;

UINT32 pa = 0;

OALMSG(OAL_MEMORY&&OAL_FUNC, (L"+OALVAtoPA(0x%08x)/r/n", pVA));

// Virtual address must be in CACHED or UNCACHED regions.虚拟内存范围

if (va < 0x80000000 || va >= 0xC0000000) {

OALMSG(OAL_ERROR, (

L"ERROR:OALVAtoPA: invalid virtual address 0x%08x/r/n", pVA

));

goto cleanUp;

}

// Address must be cached, as entries in OEMAddressTable are cached address.

va = va&~OAL_MEMORY_CACHE_BIT;

// Search the table for address range

while (pTable->size != 0) {

if (va >= pTable->CA && va <= pTable->CA + (pTable->size << 20) - 1) {

break;

}

pTable++;

}

// If address table entry is valid compute the PA

if (pTable->size != 0) pa = pTable->PA + va - pTable->CA;

cleanUp:

// Indicate physical address

OALMSG(OAL_MEMORY&&OAL_FUNC, (L"-OALVAtoPA(pa = 0x%x)/r/n", pa));

return pa;

}

//------------------------------------------------------------------------------

//从这两个函数可以看出，这个表只是为了容易修改而已，其实手动访问虚拟内存也是可

//的。至于访问GPIO 的那种访问留到有机会再说了。good luck 今天收获不小。



转载请标明:作者wogoyixikexie@gliet.桂林电子科技大学一系科协。如有错误，希望能够留言指出。