[U-Boot] MIPS cpu has problem detecting CFI

[Andrew Dyer]

On Mon, Oct 12, 2009 at 10:10 AM,  <myuboot at fastmail.fm> wrote:
> Thanks for 1) and 2).
> For 3), both results show GP register is modified.
> the result of ${CROSS_COMPILE}objdump --source cpu.o is:
>
> void flush_cache(ulong start_addr, ulong size)
> {
>  7c:   3c1c0000        lui     gp,0x0
>  80:   279c0000        addiu   gp,gp,0
>  84:   0399e021        addu    gp,gp,t9

It looks like the code expects t9 to have the gp value.  I need to get
my setup up to -current and do a build test with eldk to help much
more (we don't do much mips anymore here, so my setup is a bit behind
the times).

>        unsigned long lsize = CONFIG_SYS_CACHELINE_SIZE;
>        unsigned long addr = start_addr & ~(lsize - 1);
>  88:   2403fff0        li      v1,-16
>  8c:   00831024        and     v0,a0,v1
>        unsigned long aend = (start_addr + size - 1) & ~(lsize - 1);
>  90:   2484ffff        addiu   a0,a0,-1
>  94:   00852021        addu    a0,a0,a1
>  98:   00831824        and     v1,a0,v1
>
>        while (1) {
>                cache_op(Hit_Writeback_Inv_D, addr);
>  9c:   bc550000        cache   0x15,0(v0)
>                cache_op(Hit_Invalidate_I, addr);
>  a0:   bc500000        cache   0x10,0(v0)
>                if (addr == aend)
>  a4:   1443fffd        bne     v0,v1,9c <flush_cache+0x20>
>  a8:   24420010        addiu   v0,v0,16
>                        break;
>                addr += lsize;
>        }
> #if defined(CONFIG_TNETVxxxx)
>        invalidate_dcache();
>  ac:   8f990000        lw      t9,0(gp)
>  b0:   03200008        jr      t9
>  b4:   00000000        nop
>
> 000000b8 <do_reset>:
> void __attribute__((weak)) _machine_restart(void)
> {
> }
>

> For 4), I generated the toolchain by myself using buildroot 2009.08.
> Using built-in specs. And the result of gcc -v is:
> Target: mips-linux-uclibc
> Configured with:
> /home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/gcc-4.4.1/configure
> --prefix=/usr --build=i386-pc-linux-gnu --host=i386-pc-linux-gnu
> --target=mips-linux-uclibc --enable-languages=c
> --with-sysroot=/home/root123/sources/buildroot-2009.08-k/build_mips/staging_dir
> --with-build-time-tools=/home/root123/sources/buildroot-2009.08-k/build_mips/staging_dir/usr/mips-linux-uclibc/bin
> --disable-__cxa_atexit --enable-target-optspace --with-gnu-ld
> --disable-libssp --disable-tls --enable-shared
> --with-gmp=/home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/gmp
> --with-mpfr=/home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/mpfr
> --disable-nls --enable-threads --disable-multilib
> --disable-decimal-float --with-float=soft --with-abi=32
> --with-tune=mips32 : (reconfigured)
> /home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/gcc-4.4.1/configure
> --prefix=/usr --build=i386-pc-linux-gnu --host=i386-pc-linux-gnu
> --target=mips-linux-uclibc --enable-languages=c
> --with-sysroot=/home/root123/sources/buildroot-2009.08-k/build_mips/staging_dir
> --with-build-time-tools=/home/root123/sources/buildroot-2009.08-k/build_mips/staging_dir/usr/mips-linux-uclibc/bin
> --disable-__cxa_atexit --enable-target-optspace --with-gnu-ld
> --disable-libssp --disable-tls --enable-shared
> --with-gmp=/home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/gmp
> --with-mpfr=/home/root123/sources/buildroot-2009.08-k/toolchain_build_mips/mpfr
> --disable-nls --enable-threads --disable-multilib
> --disable-decimal-float --with-float=soft --with-abi=32
> --with-tune=mips32
> Thread model: posix
> gcc version 4.4.1 (GCC)
>
> For most of the flags above, they are automatically added by buildroot.
> Please let me know if there is anything wrong with the setting.
>

nothing stands out, but I'm not a gcc expert.

> 4) I am not familiar with ELDK. It seems to be able to create toolchain
> quickly. I will give it a try. How is the toolchain created by ELDK
> different from buildroot or openembedded?

It comes with a prebuilt toolchain.  I believe the compiler version is
a bit older than what you are running (looks like 4.2.2 from the web
page).