Follow Linux commit 10b62a2f785a (".gitignore: move *.dtb and *.dtb.S
patterns to the top-level .gitignore").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Synopsys DesignWare ARC EM Development Kit (ARC EMDK) is
an FPGA-based development platform from Synopsys aimed to speed-up
development of software for ARC EM cores and entire subsystems based on
ARC EM like Data Fusion, Secure and Sensor & Control subsystems.

U-Boot is supposed to be used as a primary bootloader on EMDK allowing
users to easily load and start their application from micro-SD card.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

As it is stated in LD manual [1] the second entry in OUTPUT_FORMAT
corresponds to "-EB" command-line option which for us is "elf32-bigarc".

[1] https://sourceware.org/binutils/docs/ld/Format-Commands.html#Format-Commands

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

This will allow for board-specific implementation of reset.
Default version will just stop execution with help of BRK instruction.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

For quite some time we have a GCC's built-in which inserts BRK
instruction so let's use it instead of simple insertion of in-line
assembly.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

This is useful for cases when U-Boot image is put in ROM and
reset vector points to 0 where the very beginnign of the image reside.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

We used to have the one and only linker script for all ARC boards
and so we relied on a particular order of symbols there.

Because of that we used __ivt_end as the marker of the end of all the
code which won't be true any longer if we move .ivt section to any other
place. That said we'd better check for each section separately.

A couple of other improvements:
 1. There's no point to include the marker of section end in interested
    range because its address is beyond the section, i.e. we should
    compare with "<" but not "<=".

 2. .ivt section for ARCv2 cores is just an array of 32-bit ints and
    they are not swapped even on little-endia cores while in case of
    ARCompact cores .ivt contains valid code so swapping is required.

 3. Just in case add check for ARC600 which is also ARCompact
    and its .ivt is normal code.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Fixes commit fac4790491f6 ("arc: Eliminate unused code and data with GCC's garbage collector"),
see [1].

Since in case of ARCv2 .ivt only contains addrresses of
interrupt/exception handlers linker doesn't understand that this section
actually make a lot of sense and decides to get rid of it if we use
"--gc-sections".

And KEEP does exactly this, see [2].

[1] http://git.denx.de/?p=u-boot.git;a=commit;h=fac4790491f69b29755d92db2cad508849573ff7
[2] https://sourceware.org/binutils/docs/ld/Input-Section-Keep.html#Input-Section-Keep

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

We don't care much about I$ line length really as there're
no per-line ops on I$ instead we only do full invalidation of it
on occasion of relocation and right before jumping to the OS.

Also as compared to Linux kernel where we don't support different
lengths of I$ and D$ lines in U-Boot we have to deal with such an
exotic configs if the target board is not supposed to run Linux kernel.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

The debug UART is intended for use very early in U-Boot to debug
problems before serial drivers are up.

Call debug_uart_init right before board_init_f.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>