some newbie questions
Ed Sutter
els at emailbox.hdtv.lucent.com
Wed Feb 18 19:08:58 UTC 2004
This is true, however, even printk() requires some of the
basic initialization of the system's low level stuff
to complete (right?), and at this point, it sounds like all
bets are off. As of this morning, the location of the
entrypoint was an unknown, so it seems like best approach
at this point is to assume nothing.
Joel Sherrill wrote:
>
> 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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