• P
    MIPS: Remove compact branch policy Kconfig entries · b03c1e3b
    Paul Burton 提交于
    Commit c1a0e9bc ("MIPS: Allow compact branch policy to be changed")
    added Kconfig entries allowing for the compact branch policy used by the
    compiler for MIPSr6 kernels to be specified. This can be useful for
    debugging, particularly in systems where compact branches have recently
    been introduced.
    
    Unfortunately mainline gcc 5.x supports MIPSr6 but not the
    -mcompact-branches compiler flag, leading to MIPSr6 kernels failing to
    build with gcc 5.x with errors such as:
    
      mipsel-linux-gnu-gcc: error: unrecognized command line option '-mcompact-branches=optimal'
      make[2]: *** [kernel/bounds.s] Error 1
    
    Fixing this by hiding the Kconfig entry behind another seems to be more
    hassle than it's worth, as MIPSr6 & compact branches have been around
    for a while now and if policy does need to be set for debug it can be
    done easily enough with KCFLAGS. Therefore remove the compact branch
    policy Kconfig entries & their handling in the Makefile.
    
    This reverts commit c1a0e9bc ("MIPS: Allow compact branch policy to
    be changed").
    Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
    Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
    Fixes: c1a0e9bc ("MIPS: Allow compact branch policy to be changed")
    Cc: stable <stable@vger.kernel.org> # v4.4+
    Cc: linux-mips@linux-mips.org
    Patchwork: https://patchwork.linux-mips.org/patch/14241/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
    b03c1e3b
Kconfig.debug 4.9 KB
menu "Kernel hacking"

config TRACE_IRQFLAGS_SUPPORT
	bool
	default y

source "lib/Kconfig.debug"

config EARLY_PRINTK
	bool "Early printk" if EXPERT
	depends on SYS_HAS_EARLY_PRINTK
	default y
	help
	  This option enables special console drivers which allow the kernel
	  to print messages very early in the bootup process.

	  This is useful for kernel debugging when your machine crashes very
	  early before the console code is initialized. For normal operation,
	  it is not recommended because it looks ugly on some machines and
	  doesn't cooperate with an X server. You should normally say N here,
	  unless you want to debug such a crash.

config EARLY_PRINTK_8250
	bool
	depends on EARLY_PRINTK && USE_GENERIC_EARLY_PRINTK_8250
	default y
	help
	  "8250/16550 and compatible serial early printk driver"
	  If you say Y here, it will be possible to use a 8250/16550 serial
	  port as the boot console.

config USE_GENERIC_EARLY_PRINTK_8250
	bool

config CMDLINE_BOOL
	bool "Built-in kernel command line"
	default n
	help
	  For most systems, it is firmware or second stage bootloader that
	  by default specifies the kernel command line options.  However,
	  it might be necessary or advantageous to either override the
	  default kernel command line or add a few extra options to it.
	  For such cases, this option allows you to hardcode your own
	  command line options directly into the kernel.  For that, you
	  should choose 'Y' here, and fill in the extra boot arguments
	  in CONFIG_CMDLINE.

	  The built-in options will be concatenated to the default command
	  line if CMDLINE_OVERRIDE is set to 'N'. Otherwise, the default
	  command line will be ignored and replaced by the built-in string.

	  Most MIPS systems will normally expect 'N' here and rely upon
	  the command line from the firmware or the second-stage bootloader.

config CMDLINE
	string "Default kernel command string"
	depends on CMDLINE_BOOL
	default ""
	help
	  On some platforms, there is currently no way for the boot loader to
	  pass arguments to the kernel.  For these platforms, and for the cases
	  when you want to add some extra options to the command line or ignore
	  the default command line, you can supply some command-line options at
	  build time by entering them here.  In other cases you can specify
	  kernel args so that you don't have to set them up in board prom
	  initialization routines.

	  For more information, see the CMDLINE_BOOL and CMDLINE_OVERRIDE
	  options.

config CMDLINE_OVERRIDE
	bool "Built-in command line overrides firmware arguments"
	default n
	depends on CMDLINE_BOOL
	help
	  By setting this option to 'Y' you will have your kernel ignore
	  command line arguments from firmware or second stage bootloader.
	  Instead, the built-in command line will be used exclusively.

	  Normally, you will choose 'N' here.

config SB1XXX_CORELIS
	bool "Corelis Debugger"
	depends on SIBYTE_SB1xxx_SOC
	select DEBUG_INFO
	help
	  Select compile flags that produce code that can be processed by the
	  Corelis mksym utility and UDB Emulator.

config DEBUG_ZBOOT
	bool "Enable compressed kernel support debugging"
	depends on DEBUG_KERNEL && SYS_SUPPORTS_ZBOOT
	default n
	help
	  If you want to add compressed kernel support to a new board, and the
	  board supports uart16550 compatible serial port, please select
	  SYS_SUPPORTS_ZBOOT_UART16550 for your board and enable this option to
	  debug it.

	  If your board doesn't support uart16550 compatible serial port, you
	  can try to select SYS_SUPPORTS_ZBOOT and use the other methods to
	  debug it. for example, add a new serial port support just as
	  arch/mips/boot/compressed/uart-16550.c does.

	  After the compressed kernel support works, please disable this option
	  to reduce the kernel image size and speed up the booting procedure a
	  little.

config SPINLOCK_TEST
	bool "Enable spinlock timing tests in debugfs"
	depends on DEBUG_FS
	default n
	help
	  Add several files to the debugfs to test spinlock speed.

config SCACHE_DEBUGFS
	bool "L2 cache debugfs entries"
	depends on DEBUG_FS
	help
	  Enable this to allow parts of the L2 cache configuration, such as
	  whether or not prefetching is enabled, to be exposed to userland
	  via debugfs.

	  If unsure, say N.

menuconfig MIPS_CPS_NS16550
	bool "CPS SMP NS16550 UART output"
	depends on MIPS_CPS
	help
	  Output debug information via an ns16550 compatible UART if exceptions
	  occur early in the boot process of a secondary core.

if MIPS_CPS_NS16550

config MIPS_CPS_NS16550_BASE
	hex "UART Base Address"
	default 0x1b0003f8 if MIPS_MALTA
	help
	  The base address of the ns16550 compatible UART on which to output
	  debug information from the early stages of core startup.

config MIPS_CPS_NS16550_SHIFT
	int "UART Register Shift"
	default 0 if MIPS_MALTA
	help
	  The number of bits to shift ns16550 register indices by in order to
	  form their addresses. That is, log base 2 of the span between
	  adjacent ns16550 registers in the system.

endif # MIPS_CPS_NS16550

endmenu
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