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++;
 }
}