Some old GNU assemblers, such as v2.14 (ELDK 3.1.1), v2.16 (ELDK 4.1.0),
warns illegal global symbol references by bal (and jal also) instruction.
This does not happen with the latest binutils v2.18.
Here's an example on gth2_config:
mips_4KC-gcc -D__ASSEMBLY__ -g -Os -D__KERNEL__ -DTEXT_BASE=0x90000000 -I/home/skuribay/devel/u-boot.git/include -fno-builtin -ffreestanding -nostdinc -isy
stem /opt/eldk311/usr/bin/../lib/gcc-lib/mips-linux/3.3.3/include -pipe -DCONFIG_MIPS -D__MIPS__ -G 0 -mabicalls -fpic -pipe -msoft-float -march=4kc -mtune=4k
c -EB -c -o cache.o cache.S
cache.S: Assembler messages:
cache.S:243: Warning: Pretending global symbol used as branch target is local.
cache.S:250: Warning: Pretending global symbol used as branch target is local.
In principle, gas might be sensitive to global symbol references in PIC
code because they should be processed through GOT (global offset table).
But if `bal' instruction is used, it results in PC-based offset jump.
This is the cause of this warning.
In practice, we know it doesn't matter whether PC-based reference or GOT-
based. As for this case, both will work before/after relocation. But let's
fix the code.
This patch explicitly sets up a target address, then jump there.
Here's an example of disassembled code with/without this patch.
90000668: 1485ffef bne a0,a1,90000628 <mips_cache_reset+0x20>
9000066c: ac80fffc sw zero,-4(a0)
90000670: 01402821 move a1,t2
-90000674: 0411ffba bal 90000560 <mips_init_icache>
-90000678: 01803021 move a2,t4
-9000067c: 01602821 move a1,t3
-90000680: 0411ffcc bal 900005b4 <mips_init_dcache>
-90000684: 01a03021 move a2,t5
-90000688: 03000008 jr t8
-9000068c: 00000000 nop
+90000674: 01803021 move a2,t4
+90000678: 8f8f83ec lw t7,-31764(gp)
+9000067c: 01e0f809 jalr t7
+90000680: 00000000 nop
+90000684: 01602821 move a1,t3
+90000688: 01a03021 move a2,t5
+9000068c: 8f8f81e0 lw t7,-32288(gp)
+90000690: 01e0f809 jalr t7
+90000694: 00000000 nop
+90000698: 03000008 jr t8
+9000069c: 00000000 nop
Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Current assembler codes are inconsistent in the way of register jump
instruction usage; some use jr, some use j. Of course GNU as allows both
usages, but as can be expected from `Jump Register' the mnemonic `jr' is
more intuitive than `j'. For example, Linux doesn't have `j <reg>' usage
at all.
Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Currently we do 1) Index_Store_Tag_I, 2) Fill and 3) Index_Store_Tag_I
again per a loop for I-cache initialization. But according to 'See MIPS
Run', we're encouraged to use three separate loops rather than combining
them *for both I- and D-cache*. This patch tries to fix this.
In accordance with fixing above, mips_init_[id]cache are separated from
mips_cache_reset(), and rewrite cache loops are completely rewritten with
useful macros.
Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
This patch replaces the current function definitions with NESTED, LEAF
and END macro. They specify some more additional information about the
function; an alignment of symbol, type of symbol, stack frame usage, etc.
These information explicitly tells the assembler and the debugger about
the types of code we want to generate.
Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
The initial intension of having mips_cache_lock() was to use the cache
as memory for temporary stack use so that a C environment can be set up
as early as possible.
But now mips_cache_lock() follow lowlevel_init(). We've already have the
real memory initilaized at this point, therefore we could/should use it.
No reason to lock at all.
Other problems:
Cache locking is not consistent across MIPS implementaions. Some imple-
mentations don't support locking at all. The style of locking varies -
some support per line locking, others per way, etc. Some parts use bits
in status registers instead of cache ops. Current mips_cache_lock() is
not necessarily general-purpose.
And this is worthy of special mention; once U-Boot/MIPS locks the lines,
they are never get unlocked, so the code relies on whatever gets loaded
after U-Boot to re-initialize the cache and clear the locks. We're sup-
posed to have CFG_INIT_RAM_LOCK and unlock_ram_in_cache() implemented,
but leave the situation as it is for a long time.
For these reasons, I proposed the removal of mips_cache_lock() from the
global start-up code.
This patch adds CFG_INIT_RAM_LOCK_MIPS to make existing users aware that
*things have changed*. If he wants the same behavior as before, he needs
to have CFG_INIT_RAM_LOCK_MIPS in his config file.
If we don't have any regression report through several releases, then
we'll remove codes entirely.
Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Acked-by: Andrew Dyer <amdyer@gmail.com>
- Add support for Altera FPGA ACEX1K
* Patches by Thomas Lange, 09 Oct 2003:
- Endian swap ATA identity for all big endian CPUs, not just PPC
- MIPS only: New option CONFIG_MEMSIZE_IN_BYTES for passing memsize
args to linux
- add support for dbau1x00 board (MIPS32)
- remove trailing white space, trailing empty lines, C++ comments, etc.
- split cmd_boot.c (separate cmd_bdinfo.c and cmd_load.c)
* Patches by Kenneth Johansson, 25 Jun 2003:
- major rework of command structure
(work done mostly by Michal Cendrowski and Joakim Kristiansen)
Add IDMA example code (tested on 8260 only)
* Add support for Purple Board (MIPS64 5Kc)
* Add support for MIPS64 5Kc CPUs
* Fix missing setting of "loadaddr" and "bootfile" on ARM and MIPS
* Patch by Denis Peter, 04 Apr 2003:
- update MIP405-4 board
* Patches by Denis Peter, 03 April 2003:
- fix PCI IRQs on MPL boards
- fix two more un-relocated pointer problems
* Fix behaviour of "run" command:
- print error message iv variable does not exist
- terminate processing of arguments in case of error
* Patches by Peter Figuli, 10 Mar 2003
- Add support for BTUART on PXA platform
- Add support for WEP EP250 (PXA) board
* Fix flash problems on INCA-IP; add tool to allow bruning images to
flash using a BDI2000
* Implement fix for I2C Edge Conditions problem for all boards that
use the bit-banging driver (common/soft_i2c.c)
* Add patches by Robert Schwebel, 31 Mar 2003:
- csb226 board: bring in sync with innokom/memsetup.S
- csb226 board: fix MDREFR handling
- misc doc fixes / extensions
- innokom board: cleanup, MDREFR fix in memsetup.S, config update
- add BOOT_PROGRESS to armlinux.c
Peter Tyser
Jean-Christophe PLAGNIOL-VILLARD
Shinya Kuribayashi
wdenk