some newbie questions
Joel Sherrill
joel.sherrill at OARcorp.com
Wed Feb 18 18:53:46 UTC 2004
Ed Sutter wrote:
> Seb,
> You can't call something with printf() in it at this level.
> Think about it...
> The guts of printf() requires console IO to be working.
> Console IO is likely handled by the serial port device
> driver in RTEMS. Since we're side-stepping the whole
> RTOS startup here, printf() will certainly not work.
But printk probably will if you have a stack and the
BSP output char hook filled it.
--joel
> Ed
>
> sebastian ssmoller wrote:
>
>>hi,
>>using an "independent" function is of cause a good idea :)
>>calling this funct does NOT cause the board to hang - so this is one step
>>into the right direction :)
>>
>>i wasnt able yet to get the value of the variable - i have to read some
>>docs about the monitor first.
>>
>>but what i did is, i only include a printf (which causes to inlcude and use
>>lots of other stuff of course). calling the funct again caused a bus error.
>>next pc points into the fstat function ...
>>
>>this let me believe that my linkcmds file is not correct. so possibly u
>>could have a look at it ?
>>
>>====== linkcmds from intro (which works) =========
>>//
>>// This linker command file was created by Introl-CODE.
>>//
>>
>>// Library modules used by this program
>>
>>// Program memory groups
>>group ROM rom itemalign 2 origin 0x0700 maxsize 0x10000-0x0700;
>> section .vectors data;
>>
>> section .start0 text;
>> section .start1 text;
>> section .start2 text;
>> section .start3 text;
>> section .start4 text;
>> section .start5 text;
>> section .start6 text;
>> section .start7 text;
>> section .start8 text;
>> section .start9 text;
>> section .startX text;
>> section .startZ text;
>>
>> section ROM.const data = .const .strings;
>> section ROM.text text = .text;
>>
>> section .init;
>>group ROM;
>>
>>set __ROMstart = 0x0700;
>>set __ROMend = 0x10000;
>>set __ROMsize = 0x10000-0x0700;
>>
>>group RAM ram bss itemalign 2 origin 0x10000 maxsize 0x50000-0x10000;
>> section .bss comms;
>> section .data data copiedfrom .init;
>> section .retm comm;
>> section .heap expand minsize 0;
>> section .stack minsize 0;
>>
>> section RAM.ubss = .ubss;
>>group RAM;
>>
>>set __RAMstart = 0x10000;
>>set __RAMend = 0x50000;
>>set __RAMsize = 0x50000-0x10000;
>>
>>group IO io bss origin 0xFFF000 maxsize 0x1000000-0xFFF000;
>> section .chip;
>>group IO;
>>
>>set __IOstart = 0xFFF000;
>>set __IOend = 0x1000000;
>>set __IOsize = 0x1000000-0xFFF000;
>>
>>// Link time variable definitions
>>set __ramstart = startof(.bss);
>>set __ramend = endof(.bss);
>>set __heapstart = startof(.heap);
>>set __heapend = endof(.heap);
>>set __stackstart = startof(.stack);
>>set __stackend = endof(.stack);
>>set __initstart = startof(.init);
>>set __initend = endof(.init);
>>set __datastart = startof(.data);
>>set __dataend = endof(.data);
>>set __fastend = endof(.start1);
>>set __chipstart = startof(.chip);
>>
>>readline; // Read files from the command line
>>
>>end;
>>
>>============ linkcmds intro end ==================
>>
>>============ linkcmds from rtems (with memory values changed) ========
>>/*
>> * This file contains GNU linker directives for a generic MC68360 board.
>> * Variations in memory size and allocation can be made by
>> * overriding some values with linker command-line arguments.
>> *
>> * Saskatchewan Accelerator Laboratory
>> * University of Saskatchewan
>> * Saskatoon, Saskatchewan, CANADA
>> * eric at skatter.usask.ca
>> *
>> * linkcmds,v 1.20 2003/01/20 20:19:44 joel Exp
>> */
>>
>>/*
>>OUTPUT_FORMAT("srec");
>>*/
>>
>>/*
>> * Declare some sizes.
>> * A heap size of 0 means `use all available memory for the heap'.
>> */
>>_RamBase = DEFINED(_RamBase) ? _RamBase : 0x10000;
>>_RamSize = DEFINED(_RamSize) ? _RamSize : 0x50000-0x10000;
>>_HeapSize = DEFINED(_HeapSize) ? _HeapSize : 0x0;
>>_StackSize = DEFINED(_StackSize) ? _StackSize : 0x1000;
>>
>>/*
>> * Declare on-board memory.
>> */
>>MEMORY {
>> rom : ORIGIN = 0x0700, LENGTH = 0x10000 - 0x0700
>> ram : ORIGIN = 0x10000, LENGTH = 0x50000 - 0x10000
>> dpram : ORIGIN = 0xFFC00001, LENGTH = 0xFFC02000 - 0xFFC00000
>>}
>>
>>/*
>> * Load objects
>> */
>>SECTIONS {
>> /*
>> * Boot PROM
>> */
>> rom : {
>> _RomBase = .;
>> } >rom
>>
>> /*
>> * Dynamic RAM
>> */
>> ram : {
>> _RamBase = .;
>> } >ram
>>
>> /*
>> * Text, data and bss segments
>> */
>> .text : {
>> *(.text)
>>
>> /*
>> * C++ constructors/destructors
>> */
>> *(.gnu.linkonce.t.*)
>>
>> /*
>> * Initialization and finalization code.
>> */
>> PROVIDE (_init = .);
>> *crti.o(.init)
>> *(.init)
>> *crtn.o(.init)
>> PROVIDE (_fini = .);
>> *crti.o(.fini)
>> *(.fini)
>> *crtn.o(.fini)
>>
>> /*
>> * Special FreeBSD sysctl sections.
>> */
>> . = ALIGN (16);
>> __start_set_sysctl_set = .;
>> *(set_sysctl_*);
>> __stop_set_sysctl_set = ABSOLUTE(.);
>> *(set_domain_*);
>> *(set_pseudo_*);
>>
>> /*
>> * C++ constructors/destructors
>> */
>> . = ALIGN (16);
>> *crtbegin.o(.ctors)
>> *(.ctors)
>> *crtend.o(.ctors)
>> *crtbegin.o(.dtors)
>> *(.dtors)
>> *crtend.o(.dtors)
>>
>> /*
>> * Exception frame info
>> */
>> . = ALIGN (16);
>> *(.eh_frame)
>>
>> /*
>> * Read-only data
>> */
>> . = ALIGN (16);
>> _rodata_start = . ;
>> *(.rodata*)
>> *(.gnu.linkonce.r*)
>>
>> . = ALIGN (16);
>> PROVIDE (etext = .);
>> } >ram
>> .data : {
>> _copy_start = .;
>> *(.data)
>> *(.gnu.linkonce.d*)
>> *(.gcc_except_table)
>> *(.jcr)
>> . = ALIGN (16);
>> PROVIDE (edata = .);
>> _copy_end = .;
>> } >ram
>> .bss : {
>> M68Kvec = .;
>> . += (256 * 4);
>> _clear_start = .;
>> *(.bss)
>> *(COMMON)
>> . = ALIGN (16);
>> PROVIDE (end = .);
>>
>> . += _StackSize;
>> . = ALIGN (16);
>> _stack_init = .;
>> _clear_end = .;
>>
>> _WorkspaceBase = .;
>> variable = .;
>> } >ram
>>
>> /*
>> * On-chip memory/peripherals
>> */
>> dpram : {
>> m360 = .;
>> . += (8 * 1024);
>> } >dpram
>>
>> /* Stabs debugging sections. */
>> .stab 0 : { *(.stab) }
>> .stabstr 0 : { *(.stabstr) }
>> .stab.excl 0 : { *(.stab.excl) }
>> .stab.exclstr 0 : { *(.stab.exclstr) }
>> .stab.index 0 : { *(.stab.index) }
>> .stab.indexstr 0 : { *(.stab.indexstr) }
>> .comment 0 : { *(.comment) }
>>
>> /* DWARF debug sections.
>> Symbols in the DWARF debugging sections are relative to the beginning
>> of the section so we begin them at 0. */
>> /* DWARF 1 */
>> .debug 0 : { *(.debug) }
>> .line 0 : { *(.line) }
>>
>> /* GNU DWARF 1 extensions */
>> .debug_srcinfo 0 : { *(.debug_srcinfo) }
>> .debug_sfnames 0 : { *(.debug_sfnames) }
>>
>> /* DWARF 1.1 and DWARF 2 */
>> .debug_aranges 0 : { *(.debug_aranges) }
>> .debug_pubnames 0 : { *(.debug_pubnames) }
>>
>> /* DWARF 2 */
>> .debug_info 0 : { *(.debug_info) }
>> .debug_abbrev 0 : { *(.debug_abbrev) }
>> .debug_line 0 : { *(.debug_line) }
>> .debug_frame 0 : { *(.debug_frame) }
>> .debug_str 0 : { *(.debug_str) }
>> .debug_loc 0 : { *(.debug_loc) }
>> .debug_macinfo 0 : { *(.debug_macinfo) }
>>
>> /* SGI/MIPS DWARF 2 extensions */
>> .debug_weaknames 0 : { *(.debug_weaknames) }
>> .debug_funcnames 0 : { *(.debug_funcnames) }
>> .debug_typenames 0 : { *(.debug_typenames) }
>> .debug_varnames 0 : { *(.debug_varnames) }
>> /* These must appear regardless of . */
>>}
>>============ linkcmds rtems end ==================
>>
>>i checked the "ca" (call) syntax again and i guess it is correct, cause it
>>works with introl code and when calling the unique_function
>>
>>many thx again
>>regards,
>>seb
>>
>>On Wed, 18 Feb 2004 12:14:30 -0500
>>Ed Sutter <els at emailbox.hdtv.lucent.com> wrote:
>>
>>
>>>Seb,
>>>Try starting with something simpler.
>>>Here's a few suggestions...
>>>
>>>In your application add a function and a variable..
>>>
>>>long unique_variable;
>>>
>>>long
>>>unique_function(void)
>>>{
>>> return(++unique_variable);
>>>}
>>>
>>>Then load your application and instead of calling the entrypoint,
>>>parse your symbol table and call this function's address. If this
>>>hangs, you have a more fundamental problem, if it doesn't hang
>>>the do some more investigation...
>>>If the "call" command that you have shows the return value of the
>>>function you called, then you should notice it incrementing.
>>>If the "call" command doesn't support that, then call the function
>>>and then display the variable using some other monitor command.
>>>
>>>Another thing to try would be to disassemble the the address of
>>>the application entrypoint and see if it makes sense.
>>>
>>>The point here is to test some of the stuff outside of RTEMS.
>>>Make sure your "call" command is working the way you think, etc...
>>>For example, maybe "call" gets confused if your address is not prefixed
>>>with "0x". Or, maybe it gets confused if yoru address IS prefixed
>>>with "0x".
>>>Get the idea? These things will just give you a confidence level
>>>(maybe good maybe not so good) in what you're doing.
>>>
>>>Ed
>>>
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