global pointer relative offset

From your post, I take it that you are trying to use microwindows.

The problem is likely to be down to a pointer being accessed using gp relative addressing when it should be using absolute addressing. A simple workaround is to add the option: -G0 to the compiler flags, although it would be better for code performance to try and track down the underlying cause of the problem.

Thanks for your help,

Yes I try to compile the eCos library with microwindows

But the modification of the debug or optimization options produce the same message

Modification of the size of some network buffers also

With the “Build Microwindows eCos support” selected only the library compilation is ok, But adding the “Build complete eCos+Microwindows application” I don’t have success.

I use the default options with the net package

Which source file is the problem in? From the code line you've presented it looks like a mouse driver. Chances are you're not going to use that particular driver, and so you could drop it from the build.

Did you try using the -G0 compiler option? Did that get you further?

Yes I tried this compiler option -g0

Also I tried to remove all the data of my mouse driver, I preserved only the device structure. And now I get the same message in an other module

« …….. ecos_install/lib/extras.o(.text.smsc_lan91cxx_init+0x30): In function `smsc_lan91cxx_init':

: global pointer relative offset 34352 at address 0x008ad9a8 out of range -32678 to 32767 «

In this case I built first the ecos library with « Microwindows eCos support selected » and then I compiled and linked my application to this library and I got the previous message.

If I build with “Build complete eCos+Microwindows application” I have the message during the library building.

nios2-elf-gcc -c -I/cygdrive/c/alt_projects/ecos_menu/ecos_install/include -I/cygdrive/c/altera/kits/nios2/components/ecos/ecos-current/packages/services/gfx/mw/current -I/cygdrive/c/altera/kits/nios2/components/ecos/ecos-current/packages/services/gfx/mw/current/src -I/cygdrive/c/altera/kits/nios2/components/ecos/ecos-current/packages/services/gfx/mw/current/tests -I. -finline-limit=7000 -g0 -O2 -ffunction-sections -fdata-sections -fno-rtti -fno-exceptions -DSYSTEM_BUS_WIDTH=32 -mno-hw-mul -mno-hw-div -I/cygdrive/c/alt_projects/ecos_menu/ecos_install/include/microwin -D__ECOS=1 -DMSDOS=0 -DELKS=0 -D__rtems__=0 -D_MINIX=0 -DNOTYET=0 -DUNIX=1 -DHAVE_FILEIO -DHAVE_BMP_SUPPORT=1 -DHAVE_PNM_SUPPORT=1 -DHAVE_XPM_SUPPORT=1 -DxHAVE_JPEG_SUPPORT=1 -DHAVESELECT=1 -o /cygdrive/c/alt_projects/ecos_menu/ecos_install/lib/ecos_app.o /cygdrive/c/altera/kits/nios2/components/ecos/ecos-current/packages/services/gfx/mw/current/src/ecos/ecos_app.c

cc1: warning: command line option "-fno-rtti" is valid for C++/ObjC++ but not for C

nios2-elf-gcc -g -nostdlib -Wl,--gc-sections -Wl,-static -mno-hw-mul -mno-hw-div -L/cygdrive/c/alt_projects/ecos_menu/ecos_install/lib -Ttarget.ld -o /cygdrive/c/alt_projects/ecos_menu/ecos_install/bin/ecos_mw.elf /cygdrive/c/alt_projects/ecos_menu/ecos_install/lib/ecos_app.o

/cygdrive/c/alt_projects/ecos_menu/ecos_install/lib/ecos_app.o(.text.cyg_user_start+0x1c): In function `cyg_user_start':

: global pointer relative offset 34348 at address 0x008700d4 out of range -32678 to 32767

I use the default options with the net package and -G0

As I understand now, some data of the .bss area are pointed with the gp + offset and the gp is constant, so this area must be lower than 0x10000.

It doesn't look like the -G0 option is really being used here. This option stops the compiler using gp relative addressing, and so should make it impossible to get the error you're showing.

Looking at the make output that you've included, the -G0 seems to be missing (Note this is -G0 and not -g0).

Make sure that you've really saved the change to the project, and try doing "generate build tree" and build "Clean" from the "Build" menu in configtool to make sure that you flush out any old settings.

Thanks very much,

Yes, I did a misunderstanding between –g0 and –G0.

With –G0 I am able to compile now the eCos library and my application.

I understand this option is only temporarily and will allow me to find which module is disturbing my working.

Thanks again.

Again me

The blocking point seems the location or the size of the MW table "__MW_APP_TAB__"

I modified the STACKSIZE in the ecos_mw_app.h, and I am able to compile without –G0

Here below an extract of the readelf file sorted by address.

The _MW_APP_TAB_ area is located in the area pointed by gp

The previous value of STACKSIZE was 65536 I modified in 15000 for this test.

What is the best way now ? to modify the STACKSIZE or to modify the location of "__MW_APP_TAB__"

Num Value Size Type Bind Vis Ndx Name

---------------------------------------------------------------

925 008685d4 2 OBJECT LOCAL DEFAULT 6 id

926 008685d8 4 OBJECT LOCAL DEFAULT 6 domainname

933 008685dc 4 OBJECT LOCAL DEFAULT 6 init.1

1686 008685e0 4 OBJECT GLOBAL DEFAULT 6 clipregion

953 008685e4 4 OBJECT LOCAL DEFAULT 6 nextimageid

1795 008685e8 4 OBJECT GLOBAL DEFAULT 6 gr_mode

2234 008685ec 6 OBJECT GLOBAL DEFAULT 6 mwstdpal1

1015 008685f4 4 OBJECT LOCAL DEFAULT 6 timerlist

1264 008685f8 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x50000000mb

1945 008685f8 0 OBJECT GLOBAL DEFAULT 6 __NET_INIT_TAB__

1675 00868604 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x60000000de

2168 00868610 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x70000000if

2474 0086861c 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x84000000in

2254 00868628 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x88000000do

2040 00868634 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x88000001do

1588 00868640 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x88000001do

2439 0086864c 12 OBJECT GLOBAL DEFAULT 6 _net_init_tab0x88000002ro

1217 00868658 15260 OBJECT GLOBAL DEFAULT 6 _mw_app_ECOS_MW_NANOX_PRI

1228 00868658 0 OBJECT GLOBAL DEFAULT 6 __NET_INIT_TAB_END__

1510 00868658 0 OBJECT GLOBAL DEFAULT 6 __MW_APP_TAB__

1199 0086c1f4 15260 OBJECT GLOBAL DEFAULT 6 _mw_app_ECOS_MW_NANOX_PRI

1127 0086fd90 0 OBJECT GLOBAL DEFAULT 6 __DEVTAB__

1153 0086fd90 0 OBJECT GLOBAL DEFAULT 6 __MW_APP_TAB_END__

1884 0086fd90 28 OBJECT GLOBAL DEFAULT 6 uart1_io

1385 0086fdac 28 OBJECT GLOBAL DEFAULT 6 jtag_uart_io

2172 0086fdc8 28 OBJECT GLOBAL DEFAULT 6 lcd_display_io

2291 0086fde4 28 OBJECT GLOBAL DEFAULT 6 tty_io_diag

2016 0086fe00 28 OBJECT GLOBAL DEFAULT 6 haldiag_io0

2150 0086fe1c 0 OBJECT GLOBAL DEFAULT 6 __DEVTAB_END__

2242 0086fe1c 64 OBJECT GLOBAL DEFAULT 6 dev_fste

2451 0086fe1c 0 OBJECT GLOBAL DEFAULT 6 cyg_fstab

1272 0086fe5c 0 OBJECT GLOBAL DEFAULT 6 cyg_mtab

1810 0086fe5c 28 OBJECT GLOBAL DEFAULT 6 dev_mte

2396 0086fe5c 0 OBJECT GLOBAL DEFAULT 6 cyg_fstab_end

1131 0086fe78 224 OBJECT GLOBAL DEFAULT 6 cyg_mtab_extra

2019 0086ff58 16 OBJECT GLOBAL DEFAULT 6 lan91c111_netdev

2137 0086ff58 0 OBJECT GLOBAL DEFAULT 6 cyg_mtab_end

2313 0086ff58 0 OBJECT GLOBAL DEFAULT 6 __NETDEVTAB__

1194 0086ff68 0 OBJECT GLOBAL DEFAULT 6 cyg_nstab

1609 0086ff68 28 OBJECT GLOBAL DEFAULT 6 cyg_bsd_nste

2122 0086ff68 0 OBJECT GLOBAL DEFAULT 6 __NETDEVTAB_END__

7 0086ff84 0 SECTION LOCAL DEFAULT 7

1804 0086ff84 0 OBJECT GLOBAL DEFAULT 6 cyg_nstab_end

1991 0086ff84 4 OBJECT GLOBAL DEFAULT 7 startup_thread

1995 0086ff84 0 NOTYPE GLOBAL DEFAULT ABS __bss_start

2260 0086ff84 0 NOTYPE GLOBAL DEFAULT ABS _edata

65 0086ff88 4 OBJECT LOCAL DEFAULT 7 lan91cxx_interrupt_handle

102 0086ff8c 4 OBJECT LOCAL DEFAULT 7 _no_data

113 0086ff90 1 OBJECT LOCAL DEFAULT 7 fileio_initializer

2469 0086ff94 4 OBJECT GLOBAL DEFAULT 7 idle_thread_loops

2430 0086ff98 8 OBJECT GLOBAL DEFAULT 7 _ZN10Cyg_Thread17exceptio

1166 0086ffa0 4 OBJECT GLOBAL DEFAULT 7 _ZN13Cyg_Interrupt8dsr_li

--------------------

1017 008702b0 8 OBJECT LOCAL DEFAULT 7 current_time

1029 008702b8 4 OBJECT LOCAL DEFAULT 7 cyg_libc_atexit_handlers_

40 008702bc 15000 OBJECT LOCAL DEFAULT 7 startup_stack

1330 00870324 0 NOTYPE GLOBAL DEFAULT ABS _gp

1248 00873d54 240 OBJECT GLOBAL DEFAULT 7 startup_thread_obj

66 00873e44 28 OBJECT LOCAL DEFAULT 7 lan91cxx_interrupt

Thanks again Monkeyboy

The instructions that you provided, move the ecos table out of the area pointed by gp and its remains in the rwdata.

But the memory footprint is not optimized.

We have always some big arrays (=65796) in the rwdata which are normally preserved in Flash. For embedded system with a small flash is not a good point.

It seems it is due to the _mw_app_entry structure declared in the ecos_mw_app.h

The first fields are initialized and must be preserved in Flash but the last field stack[STACKSIZE] should be in bss (with STACKSIZE=65536). This structure should be perhaps split in two parts.