I'm using:
yagarto-bu-2.23.1_gcc-4.7.2-c-c++_nl-1.20.0_gdb-7.5.1_eabi_20121222
and it is working well with a project containing dozens of source files.
Then I add the following source files:
FooClass.h
1 | class FooClass {
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2 | public:
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3 | FooClass(){};
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4 | static FooFrame m_fooFrame;
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5 | };
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FooClass.cpp
1 | #include "FooClass.h"
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2 | FooFrame FooClass::m_fooFrame;
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Here's the file for the static member:
FooFrame.h
1 | class FooFrame {
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2 | public:
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3 | FooFrame(){};
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4 | };
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No need for FooFrame.cpp
Trivial right? Well, the result is that static vars are erroneously
shifted in memory by 4 bytes.
Here's the map file. These vars reside at __data_start and are copied
there from ROM by the startup code. Adding FooClass doesn't alter these
vars at the beginning. That's all fine and dandy.
1 | 0x40000200 0x1 src\UserIO.o
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2 | 0x40000200 UserIO::m_dummySystemStatus
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3 | *fill* 0x40000201 0x3
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4 | .data._ZN3SAL15m_uart0BaudRateE
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5 | 0x40000204 0x4 src\SAL.o
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6 | 0x40000204 SAL::m_uart0BaudRate
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7 | .data._ZN3SAL15m_uart1BaudRateE
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8 | 0x40000208 0x4 src\SAL.o
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9 | 0x40000208 SAL::m_uart1BaudRate
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This is the happy memory of the ARM7 before adding FooClass:
1 | 40000200 01000000 80250000 80250000 01010100
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This is correct. You can see m_dummySystemStatus, and the two baud rates
(9600 baud becomes 0x80250000 :-). Great!
Now lets add FooClass to the project and look at memory:
1 | 40000200 FFFFFFFF 01000000 80250000 80250000
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What the heck? You can see that the static members have been moved by 1
word (4 bytes) and any code that uses them crashes in a pile.
I'm using James P. Lynch's linker script (modified for the LPC2148):
1 | /* Author: James P. Lynch */ /* identify the Entry Point */
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2 |
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3 | ENTRY(_startup)
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4 | /* specify the LPC2148 memory areas */
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5 |
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6 | MEMORY
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7 | {
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8 | flash : ORIGIN = 0, LENGTH = 512K /* FLASH ROM */
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9 | ram_isp_low(A) : ORIGIN = 0x40000120, LENGTH = 223 /* variables used by Philips ISP bootloader */
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10 | ram : ORIGIN = 0x40000200, LENGTH = 32224 /* free RAM area */
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11 | ram_isp_high(A) : ORIGIN = 0x40007FE0, LENGTH = 32 /* variables used by Philips ISP bootloader */
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12 | }
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13 |
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14 |
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15 | /* define a global symbol _stack_end */
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16 |
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17 | _stack_end = 0x40007EDC;
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18 |
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19 | /* now define the output sections */
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20 |
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21 | SECTIONS
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22 | {
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23 | . = 0; /* set location counter to address zero */
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24 |
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25 | startup : {
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26 | *(.startup)
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27 | . = ALIGN(0x4);
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28 | } >flash /* the startup code goes into FLASH */
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29 |
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30 |
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31 |
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32 | .text : {
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33 | CREATE_OBJECT_SYMBOLS
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34 | *(.text .text.* .gnu.linkonce.t.*)
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35 | *(.plt)
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36 | *(.gnu.warning)
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37 | *(.glue_7t) *(.glue_7)
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38 |
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39 | . = ALIGN (4);
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40 | /* These are for static constructors and destructors under ELF */
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41 | KEEP (*crtbegin.o(.ctors))
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42 | KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
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43 | KEEP (*(SORT(.ctors.*)))
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44 | KEEP (*crtend.o(.ctors))
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45 | KEEP (*crtbegin.o(.dtors))
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46 | KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
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47 | KEEP (*(SORT(.dtors.*)))
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48 | KEEP (*crtend.o(.dtors))
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49 |
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50 | *(.rodata .rodata.* .gnu.linkonce.r.*)
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51 |
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52 | *(.ARM.extab* .gnu.linkonce.armextab.*)
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53 | *(.gcc_except_table)
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54 | *(.eh_frame_hdr)
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55 | *(.eh_frame)
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56 |
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57 | *(.init)
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58 | *(.fini)
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59 |
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60 | PROVIDE_HIDDEN (__preinit_array_start = .);
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61 | KEEP (*(.preinit_array))
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62 | PROVIDE_HIDDEN (__preinit_array_end = .);
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63 | PROVIDE_HIDDEN (__init_array_start = .);
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64 | KEEP (*(SORT(.init_array.*)))
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65 | KEEP (*(.init_array))
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66 | PROVIDE_HIDDEN (__init_array_end = .);
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67 | PROVIDE_HIDDEN (__fini_array_start = .);
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68 | KEEP (*(.fini_array))
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69 | KEEP (*(SORT(.fini_array.*)))
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70 | PROVIDE_HIDDEN (__fini_array_end = .);
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71 | } >flash
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72 |
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73 | /* .ARM.exidx is sorted, so has to go in its own output section. */
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74 | .ARM.exidx : {
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75 | __exidx_start = .;
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76 | *(.ARM.exidx* .gnu.linkonce.armexidx.*)
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77 | __exidx_end = .;
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78 | } >flash
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79 | _etext = .;
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80 |
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81 |
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82 |
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83 | .data : {
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84 | __data_load = LOADADDR (.data);
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85 | __data_start = .;
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86 | KEEP(*(.jcr))
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87 | *(.got.plt) *(.got)
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88 | *(.shdata)
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89 | *(.data .data.* .gnu.linkonce.d.*)
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90 | . = ALIGN (4);
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91 | _edata = .;
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92 | } >ram AT >flash
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93 |
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94 | .bss : {
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95 | __bss_start__ = . ;
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96 | *(.shbss)
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97 | *(.bss .bss.* .gnu.linkonce.b.*)
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98 | *(COMMON)
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99 | . = ALIGN (4);
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100 | __bss_end__ = .;
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101 | } >ram
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102 |
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103 | }
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104 | _end = .; /* define a global symbol marking the end of application RAM */
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So my question is, can you help me identify where I'm going wrong?
Thank you!
David
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