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Dear All,
I'm trying to tracking the .lst file as the below. but I'm confused what is the current pc value?
Fron here, 0x010002b4: 4902 .I LDR r1,[pc,#8] ; [0x10002c0] = 0x20000000
Does [0x10002c0] mean the current 'pc' value or should I have to consider that value already calculated by #8?
What exactly does 0x10002c0 mean?
... SystemInit 0x010002b4: 4902 .I LDR r1,[pc,#8] ; [0x10002c0] = 0x20000000 0x010002b6: 4801 .H LDR r0,[pc,#4] ; [0x10002bc] = 0x2faf080 0x010002b8: 6008 .' STR r0,[r1,#0] 0x010002ba: 4770 pG BX lr $d 0x010002bc: 02faf080 .... DCD 50000000 0x010002c0: 20000000 ... DCD 536870912 $t
Thanks in advance.
You need to post it as for source code:
www.danlhenry.com/.../keil_code.png
Oh.. of course yes.
Here is the code, Especially I don't know what does [0x10002c0] mean at the below.
SystemInit 0x010002b4: 4902 .I LDR r1,[pc,#8] ; [0x10002c0] = 0x20000000
RESET __Vectors 0x01000000: 20000208 ... DCD 536871432 0x01000004: 010002c5 .... DCD 16777925 0x01000008: 010002cd .... DCD 16777933 0x0100000c: 010002cf .... DCD 16777935 0x01000010: 010002d1 .... DCD 16777937 0x01000014: 010002d3 .... DCD 16777939 0x01000018: 010002d5 .... DCD 16777941 __main_after_scatterload _main_clock _main_cpp_init _main_init 0x010000c8: 4800 .H LDR r0,[pc,#0] ; [0x10000cc] = 0x10001bf 0x010000ca: 4700 .G BX r0 $d 0x010000cc: 010001bf .... DCD 16777663 .ARM.Collect$$$$00002712 __lit__00000000 __rt_final_cpp __rt_final_exit 0x010000d0: 20000208 ... DCD 536871432 $t .emb_text FlashLoader_ASM 0x010000d4: 2000 . MOVS r0,#0 0x010000de: 0000 .. MOVS r0,r0 .text UartStdOutInit 0x010000e0: 4848 HH LDR r0,[pc,#288] ; [0x1000204] = 0x010000fe: 4770 pG BX lr 0x010001ba: 6021 !' STR r1,[r4,#0] 0x010001bc: e7fe .. B 0x10001bc ; FlashLoader + 160 main 0x010001be: 4811 .H LDR r0,[pc,#68] ; [0x1000204] = 0x40006000 0x010001c0: b510 .. PUSH {r4,lr} 0x010001c2: 2110 .! MOVS r1,#0x10 0x010001c4: 6101 .a STR r1,[r0,#0x10] 0x010001c6: 2141 A! MOVS r1,#0x41 0x010002a8: 0000000a .... DCD 10 $t .text SystemCoreClockUpdate 0x010002ac: 4904 .I LDR r1,[pc,#16] ; [0x10002c0] = 0x20000000 0x010002ae: 4803 .H LDR r0,[pc,#12] ; [0x10002bc] = 0x2faf080 0x010002b0: 6008 .' STR r0,[r1,#0] 0x010002b2: 4770 pG BX lr SystemInit 0x010002b4: 4902 .I LDR r1,[pc,#8] ; [0x10002c0] = 0x20000000 0x010002b6: 4801 .H LDR r0,[pc,#4] ; [0x10002bc] = 0x2faf080 0x010002b8: 6008 .' STR r0,[r1,#0] 0x010002ba: 4770 pG BX lr $d 0x010002bc: 02faf080 .... DCD 50000000 0x010002c0: 20000000 ... DCD 536870912 $t .text Reset_Handler 0x010002c4: 4806 .H LDR r0,[pc,#24] ; [0x10002e0] = 0x10002b5 0x010002c6: 4780 .G BLX r0 0x010002c8: 4806 .H LDR r0,[pc,#24] ; [0x10002e4] = 0x10000c1 0x010002ca: 4700 .G BX r0
I want to add one more question. Where is the __rt_entry ?, Especially I want to know where exactly to start jump to main() function from startup code.
It is the computed address of PC+8 which then holds the literal 0x20000000 The literal pool being placed outside of the executing code If using assembler, perhaps take a course on it
Thanks so much letting me know it,
never mind the below question.
Now I'm trying to understand the startup.s code of Cortex CM3 with assembly code also. I come across the "Application Note 107 - ARM Infocenter", it say that booting sequence goes to __main then __rt_entry sequence. and automatically after __rt_entry, main is called. so far I get it.
But problem is that I can't grep "__rt_entry" in the source files. So I asked this question also.
Once I'll try again to understand the startup.s code.
Thanks.
The linker builds structures describing the load regions and initialization in the form of copying and zeroing regions of RAM. It also pulls in library code to perform these run time start up tasks, whether it is the scatter loader, or decompression routines for the statics. Some of these things will not be provided to you in source code form.