bcm63xx/u-boot/arch/mips/lib/Makefile, branch master

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12Z

When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini

MIPS: Stop building position independent code

2017-07-25T18:44:00Z

U-Boot has up until now built with -fpic for the MIPS architecture, producing position independent code which uses indirection through a global offset table, making relocation fairly straightforward as it simply involves patching up GOT entries. Using -fpic does however have some downsides. The biggest of these is that generated code is bloated in various ways. For example, function calls are indirected through the GOT & the t9 register: 8f998064 lw t9,-32668(gp) 0320f809 jalr t9 Without -fpic the call is simply: 0f803f01 jal be00fc04 This is more compact & faster (due to the lack of the load & the dependency the jump has on its result). It is also easier to read & debug because the disassembly shows what function is being called, rather than just an offset from gp which would then have to be looked up in the ELF to discover the target function. Another disadvantage of -fpic is that each function begins with a sequence to calculate the value of the gp register, for example: 3c1c0004 lui gp,0x4 279c3384 addiu gp,gp,13188 0399e021 addu gp,gp,t9 Without using -fpic this sequence no longer appears at the start of each function, reducing code size considerably. This patch switches U-Boot from building with -fpic to building with -fno-pic, in order to gain the benefits described above. The cost of this is an extra step during the build process to extract relocation data from the ELF & write it into a new .rel section in a compact format, plus the added complexity of dealing with multiple types of relocation rather than the single type that applied to the GOT. The benefit is smaller, cleaner, more debuggable code. The relocate_code() function is reimplemented in C to handle the new relocation scheme, which also makes it easier to read & debug. Taking maltael_defconfig as an example the size of u-boot.bin built using the Codescape MIPS 2016.05-06 toolchain (gcc 4.9.2, binutils 2.24.90) shrinks from 254KiB to 224KiB. Signed-off-by: Paul Burton Cc: Daniel Schwierzeck Cc: u-boot@lists.denx.de Reviewed-by: Daniel Schwierzeck Tested-by: Daniel Schwierzeck

MIPS: add handling for generic and EJTAG exceptions

2016-11-30T15:12:17Z

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 Reviewed-by: Paul Burton Tested-by: Paul Burton

MIPS: reserve space for exception vectors

2016-11-30T15:11:46Z

In order to set own exception handlers, a table with the exception vectors must be built in DRAM and the CPU EBase register must be set to the base address of this table. Reserve the space above the stack and use gd->irq_sp as storage for the exception base address. Signed-off-by: Daniel Schwierzeck

MIPS: Support dynamic I/O port base address

2016-02-01T21:13:25Z

The existing mips_io_port_base variable isn't suitable for use early during boot since it will be stored in the .data section which may not be writable pre-relocation. Fix this by moving the I/O port base address into struct arch_global_data. In order to avoid adding this field for all targets, make this dependant upon a new Kconfig entry CONFIG_DYNAMIC_IO_PORT_BASE. Malta is the only board which sets a non-zero I/O port base, so select this option only for Malta. Signed-off-by: Paul Burton

MIPS: unify cache initialization code

2015-01-29T11:55:01Z

The mips32 & mips64 cache initialization code differs only in that the mips32 code supports reading the cache size from coprocessor 0 registers at runtime. Move the more developed mips32 version to a common arch/mips/lib/cache_init.S & remove the now-redundant mips64 version in order to reduce duplication. The temporary registers used are shuffled slightly in order to work for both mips32 & mips64 builds. The RA register is defined differently to suit mips32 & mips64, but will be removed by a later commit in the series after further cleanup. Signed-off-by: Paul Burton Cc: Daniel Schwierzeck

MIPS: unify cache maintenance functions

2015-01-29T11:55:00Z

Move the more developed mips32 version of the cache maintenance functions to a common arch/mips/lib/cache.c, in order to reduce duplication between mips32 & mips64. Signed-off-by: Paul Burton Cc: Daniel Schwierzeck

MIPS: remove board.c

2014-11-27T15:20:37Z

After all MIPS boards are switched to generic-board, the MIPS specific board.c can be removed. Signed-off-by: Daniel Schwierzeck

MIPS: allow use of generic board

2014-04-20T11:16:43Z

This patch allows MIPS boards to make use of generic board, replacing arch/mips/lib/board.c with common/board_{f,r}.c and struct bd_info with the asm-generic version. Signed-off-by: Paul Burton

MIPS: move mips_io_port_base out of board.c

2014-04-20T11:16:42Z

Move the definition of this variable out of arch/mips/lib/board.c in preparation for allowing use of generic board on MIPS, which will lead to this file not being compiled. Signed-off-by: Paul Burton