When writing code, for example during relocation, we ensure that the
icache has a coherent view of the new instructions with a call to
flush_cache(). This handles the bulk of the work to ensure the new
instructions will execute as expected, however it does not ensure that
the CPU pipeline doesn't already contain instructions taken from a stale
view of the affected memory. This could theoretically be a problem for
relocation, but in practice typically isn't because we sync caches for
enough code after the entry point of the newly written code that by the
time the CPU pipeline might possibly fetch any of it we'll have long ago
written it back & invalidated any stale icache entries. This is however
a problem for shorter regions of code.
In preparation for later patches which write shorter segments of code,
ensure any instruction hazards are cleared by flush_cache() by
introducing & using a new instruction_hazard_barrier() function which
makes use of the jr.hb instruction to clear the hazard.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: u-boot@lists.denx.de
Add exception handlers for generic and EJTAG exceptions. Most of
the assembly code is imported from Linux kernel and adapted to U-Boot.
The exception vector table will be reserved above the stack before
U-Boot is relocated. The exception handlers will be installed and
activated after relocation in the initr_traps hook function.
Generic exceptions are handled by showing a CPU register dump similar
to Linux kernel. For example:
malta # md 1
00000001:
Ooops:
$ 0 : 00000000 00000000 00000009 00000004
$ 4 : 8ff7e108 00000000 0000003a 00000000
$ 8 : 00000008 00000001 8ff7cd18 00000004
$12 : 00000002 00000000 00000005 0000003a
$16 : 00000004 00000040 00000001 00000001
$20 : 00000000 8fff53c0 00000008 00000004
$24 : ffffffff 8ffdea44
$28 : 90001650 8ff7cd00 00000004 8ffe6818
Hi : 00000000
Lo : 00000004
epc : 8ffe6848 (text bfc28848)
ra : 8ffe6818 (text bfc28818)
Status: 00000006
Cause : 00000410 (ExcCode 04)
BadVA : 8ff9e928
PrId : 00019300
### ERROR ### Please RESET the board ###
EJTAG exceptions are checked for SDBBP and delegated to the SDBBP handler
if necessary. Otherwise the debug mode will simply be exited. The SDBBP
handler currently prints the contents of registers c0_depc and c0_debug.
This could be extended in the future to handle semi-hosting according to
the MIPS UHI specification.
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Tested-by: Paul Burton <paul.burton@imgtec.com>
The kernel changed it a long time ago. Also this is now broken
on gcc-5.x.
Reported-by: Andy Kennedy <andy.kennedy@adtran.com>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Linux Kernel abolished include/linux/config.h long time ago.
(around version v2.6.18..v2.6.19)
We don't need to provide Linux copatibility any more.
This commit deletes include/linux/config.h
and fixes source files not to include this.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
This helps to clean up the include/ directory so that it only contains
non-architecture-specific headers and also matches Linux's directory
layout which many U-Boot developers are already familiar with.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
