首先说明一下芯片内存情况：片内flash地址为0x00000000,大小为256K,片内sram为0x20000000,大小为64K.
现在想把代码放到SRAM运行，下面给出分散加载文件和编译时的map输出
FLASH 0x00000000 0x00010000
{
RESET 0x00000000 0x00010000
{
*.o (RESET, +First)
}
RO +0x20000000 0x00010000
{
* (+RO)
}
RW +0 0x00010000
{
* (+RW)
}
ZI +0 0x00010000
{
* (+ZI)
}
}
map输出：
================================================================================
Memory Map of the image
Image Entry point : 0x0000006f
Load Region FLASH (Base: 0x00000000, Size: 0x00000d70, Max: 0x00010000, ABSOLUTE)
Execution Region RESET (Base: 0x00000000, Size: 0x000000d8, Max: 0x00010000, ABSOLUTE)
Base Addr Size Type Attr Idx E Section Name Object
0x00000000 0x000000b8 Code RO 159 * RESET bl_startup_rvmdk.o
0x000000b8 0x0000000a Ven RO 178 Veneer$$Code anon$$obj.o
0x000000c2 0x0000000a Ven RO 179 Veneer$$Code anon$$obj.o
0x000000cc 0x0000000a Ven RO 180 Veneer$$Code anon$$obj.o
Execution Region RO (Base: 0x200000d8, Size: 0x00000c34, Max: 0x00010000, ABSOLUTE)
Base Addr Size Type Attr Idx E Section Name Object
0x200000d8 0x00000048 Code RO 28 .text bl_check.o
0x20000120 0x00000b90 Code RO 55 .text bl_enet.o
0x20000cb0 0x00000024 Code RO 171 .text memcpya.o(mc_w.l)
0x20000cd4 0x00000026 Code RO 173 .text memseta.o(mc_w.l)
0x20000cfa 0x0000000a Ven RO 181 Veneer$$Code anon$$obj.o
0x20000d04 0x00000006 Data RO 57 .constdata bl_enet.o
Execution Region RW (Base: 0x20000d0c, Size: 0x00000064, Max: 0x00010000, ABSOLUTE)
Base Addr Size Type Attr Idx E Section Name Object
0x20000d0c 0x00000064 Data RW 56 .data bl_enet.o
Execution Region ZI (Base: 0x20000d70, Size: 0x0000041c, Max: 0x00010000, ABSOLUTE)
Base Addr Size Type Attr Idx E Section Name Object
0x20000d70 0x0000035c Zero RW 58 .bss bl_enet.o
0x200010cc 0x000000c0 Zero RW 158 .bss bl_startup_rvmdk.o
================================================================================
一开机就开始运行如下这段代码
ProcessorInit
;
; Copy the code image from flash to SRAM.
;
movs r0, #0x00000000
ldr r1, =0x20000000
import ||Image$$ZI$$Base||
ldr r2, =||Image$$ZI$$Base||
copy_loop
ldr r3, [r0], #4
str r3, [r1], #4
cmp r1, r2
blt copy_loop
;
; Zero fill the .bss section.
;
movs r0, #0x00000000
import ||Image$$ZI$$Limit||
ldr r2, =||Image$$ZI$$Limit||
zero_loop
str r0, [r1], #4
cmp r1, r2
blt zero_loop
;
; Set the vector table pointer to the beginning of SRAM.
;
ldr r0, =0xe000ed08
ldr r1, =0x20000000
str r1, [r0]
orr lr, lr, #0x20000000
bx lr
在执行这段代码的时候，发现||Image$$ZI$$Limit||的值和||Image$$ZI$$Base||居然是一样的，都为0x20000d70。根据map的输出，这两个值不应该相等啊？
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