手机开发实战184——Scatter file介绍5

分散加载文件中定义如下：

    Exec_Sram  0x80000000  0x40000

    {

        * (sram)

    }

“PI” 属性使用示例：

LR_1 0x010000 PI                ; The first load region is at 0x010000.

{

    ER_RO +0                    ; The PI attribute is inherited from parent.

                                ; The default execution address is 0x010000, but the code can be moved.

    {

        *(+RO)                  ; All the RO sections go here.

    }

    ER_RW +0 ABSOLUTE           ; PI attribute is overridden by ABSOLUTE.

    {

        *(+RW)                  ; The RW sections are placed next. They cannot be moved.

    }

    ER_ZI +0                    ; ER_ZI region placed after ER_RW region.

    {

        *(+ZI)                  ; All the ZI sections are placed consecutively here.

    }

}

LR_1 0x010000                   ; The first load region is at 0x010000.

{

    ER_RO +0                    ; Default ABSOLUTE attribute is inherited from parent. The execution address

                                ; is 0x010000. The code and ro data cannot be moved.

    {

        *(+RO)                  ; All the RO sections go here.

    }

    ER_RW 0x018000 PI           ; PI attribute overrides ABSOLUTE

    {

        *(+RW)                  ; The RW sections are placed at 0x018000 and they can be moved.

    }

    ER_ZI +0                    ; ER_ZI region placed after ER_RW region.

    {

        *(+ZI)                  ; All the ZI sections are placed consecutively here.

    }

}

程序中对某区域地址等的引用方法：

Load$region_name$Base             Load address of the region.

Image$region_name$Base            Execution address of the region.

Image$region_name$Length          Execution region length in bytes (multiple of 4).

Image$region_name$Limit           Address of the byte beyond the end of the execution region.

Image$region_name$ZI$Base        Execution address of the ZI output section in this region.

Image$region_name$ZI$Length      Length of the ZI output section in bytes (multiple of 4).

Image$region_name$ZI$Limit       Address of the byte beyond the end of the ZI output sectionin the execution region.

SectionName$Base                   Input Address of the start of the consolidated section called SectionName.

SectionName$Limit                  Input Address of the byte beyond the end of the consolidated section called SectionName.

Load：          加载区，即存放地址；

Image：         执行区，即运行地址；

Base：          区首地址；

Limit：         区尾地址；

Length：        区长度；

region_name：   RO、RW、ZI、load_region_name、execution_region_name；

例如：

    “RAM1”区域的首地址：      Image$RAM1$Base

    上例中“sram”段首地址：    sram$Base

汇编引用示例：

  IMPORT |Load$Exec_RAM1$Base|              // Exec_RAM1 为“RW”段

  IMPORT |Image$Exec_RAM1$Base|

  IMPORT |Image$Exec_RAM1$Length|

  IMPORT |Image$Exec_RAM1$Limit|

  LDR  R0, =|Load$Exec_RAM1$Base|

  LDR  R1, =|Image$Exec_RAM1$Base|

  LDR  R2, =|Image$Exec_RAM1$Limit|

0

  CMP  R1,   R2

  LDRCC R3,   [R0], #4

  STRCC R3,   [R1], #4

  BCC  %b0

C 引用：

extern unsigned char Load$Exec_RAM1$Base;

extern unsigned char Image$Exec_RAM1$Base;

extern unsigned char Image$Exec_RAM1$Length;

void MoveRO(void)

{

 unsigned char * psrc, *pdst;

 unsigned int  count;

 count = (unsigned int)   &Image$Exec_RAM1$Length;

 psrc  = (unsigned char *)&Load$Exec_RAM1$Base;

 pdst  = (unsigned char *)&Image$Exec_RAM1$Base;

 while (count--) {

  *pdst++ = *psrc++;

 }

}