1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
>> 2 menu "Kernel hacking"
2 3
3 config 16KSTACKS !! 4 config TRACE_IRQFLAGS_SUPPORT
4 bool "Use 16Kb for kernel stacks inste !! 5 bool
>> 6 default y
>> 7
>> 8 source "lib/Kconfig.debug"
>> 9
>> 10 config EARLY_PRINTK
>> 11 bool "Early printk" if EXPERT
>> 12 depends on SYS_HAS_EARLY_PRINTK
>> 13 default y
>> 14 help
>> 15 This option enables special console drivers which allow the kernel
>> 16 to print messages very early in the bootup process.
>> 17
>> 18 This is useful for kernel debugging when your machine crashes very
>> 19 early before the console code is initialized. For normal operation,
>> 20 it is not recommended because it looks ugly on some machines and
>> 21 doesn't cooperate with an X server. You should normally say N here,
>> 22 unless you want to debug such a crash.
>> 23
>> 24 config EARLY_PRINTK_8250
>> 25 bool
>> 26 depends on EARLY_PRINTK && USE_GENERIC_EARLY_PRINTK_8250
>> 27 default y
>> 28 help
>> 29 "8250/16550 and compatible serial early printk driver"
>> 30 If you say Y here, it will be possible to use a 8250/16550 serial
>> 31 port as the boot console.
>> 32
>> 33 config USE_GENERIC_EARLY_PRINTK_8250
>> 34 bool
>> 35
>> 36 config CMDLINE_BOOL
>> 37 bool "Built-in kernel command line"
>> 38 default n
>> 39 help
>> 40 For most systems, it is firmware or second stage bootloader that
>> 41 by default specifies the kernel command line options. However,
>> 42 it might be necessary or advantageous to either override the
>> 43 default kernel command line or add a few extra options to it.
>> 44 For such cases, this option allows you to hardcode your own
>> 45 command line options directly into the kernel. For that, you
>> 46 should choose 'Y' here, and fill in the extra boot arguments
>> 47 in CONFIG_CMDLINE.
>> 48
>> 49 The built-in options will be concatenated to the default command
>> 50 line if CMDLINE_OVERRIDE is set to 'N'. Otherwise, the default
>> 51 command line will be ignored and replaced by the built-in string.
>> 52
>> 53 Most MIPS systems will normally expect 'N' here and rely upon
>> 54 the command line from the firmware or the second-stage bootloader.
>> 55
>> 56 config CMDLINE
>> 57 string "Default kernel command string"
>> 58 depends on CMDLINE_BOOL
>> 59 default ""
>> 60 help
>> 61 On some platforms, there is currently no way for the boot loader to
>> 62 pass arguments to the kernel. For these platforms, and for the cases
>> 63 when you want to add some extra options to the command line or ignore
>> 64 the default command line, you can supply some command-line options at
>> 65 build time by entering them here. In other cases you can specify
>> 66 kernel args so that you don't have to set them up in board prom
>> 67 initialization routines.
>> 68
>> 69 For more information, see the CMDLINE_BOOL and CMDLINE_OVERRIDE
>> 70 options.
>> 71
>> 72 config CMDLINE_OVERRIDE
>> 73 bool "Built-in command line overrides firmware arguments"
>> 74 default n
>> 75 depends on CMDLINE_BOOL
>> 76 help
>> 77 By setting this option to 'Y' you will have your kernel ignore
>> 78 command line arguments from firmware or second stage bootloader.
>> 79 Instead, the built-in command line will be used exclusively.
>> 80
>> 81 Normally, you will choose 'N' here.
>> 82
>> 83 config SB1XXX_CORELIS
>> 84 bool "Corelis Debugger"
>> 85 depends on SIBYTE_SB1xxx_SOC
>> 86 select DEBUG_INFO if !COMPILE_TEST
>> 87 help
>> 88 Select compile flags that produce code that can be processed by the
>> 89 Corelis mksym utility and UDB Emulator.
>> 90
>> 91 config DEBUG_ZBOOT
>> 92 bool "Enable compressed kernel support debugging"
>> 93 depends on DEBUG_KERNEL && SYS_SUPPORTS_ZBOOT
>> 94 default n
>> 95 help
>> 96 If you want to add compressed kernel support to a new board, and the
>> 97 board supports uart16550 compatible serial port, please select
>> 98 SYS_SUPPORTS_ZBOOT_UART16550 for your board and enable this option to
>> 99 debug it.
>> 100
>> 101 If your board doesn't support uart16550 compatible serial port, you
>> 102 can try to select SYS_SUPPORTS_ZBOOT and use the other methods to
>> 103 debug it. for example, add a new serial port support just as
>> 104 arch/mips/boot/compressed/uart-16550.c does.
>> 105
>> 106 After the compressed kernel support works, please disable this option
>> 107 to reduce the kernel image size and speed up the booting procedure a
>> 108 little.
>> 109
>> 110 config SPINLOCK_TEST
>> 111 bool "Enable spinlock timing tests in debugfs"
>> 112 depends on DEBUG_FS
>> 113 default n
>> 114 help
>> 115 Add several files to the debugfs to test spinlock speed.
>> 116
>> 117 config SCACHE_DEBUGFS
>> 118 bool "L2 cache debugfs entries"
>> 119 depends on DEBUG_FS
>> 120 help
>> 121 Enable this to allow parts of the L2 cache configuration, such as
>> 122 whether or not prefetching is enabled, to be exposed to userland
>> 123 via debugfs.
>> 124
>> 125 If unsure, say N.
>> 126
>> 127 menuconfig MIPS_CPS_NS16550_BOOL
>> 128 bool "CPS SMP NS16550 UART output"
>> 129 depends on MIPS_CPS
5 help 130 help
6 If you say Y here the kernel will us !! 131 Output debug information via an ns16550 compatible UART if exceptions
7 kernel stack attached to each proces !! 132 occur early in the boot process of a secondary core.
8 This increases the resident kernel f !! 133
9 threads to run on the system and als !! 134 if MIPS_CPS_NS16550_BOOL
10 on the VM subsystem for higher order !! 135
>> 136 config MIPS_CPS_NS16550
>> 137 def_bool MIPS_CPS_NS16550_BASE != 0
>> 138
>> 139 config MIPS_CPS_NS16550_BASE
>> 140 hex "UART Base Address"
>> 141 default 0x1b0003f8 if MIPS_MALTA
>> 142 default 0
>> 143 help
>> 144 The base address of the ns16550 compatible UART on which to output
>> 145 debug information from the early stages of core startup.
>> 146
>> 147 This is only used if non-zero.
>> 148
>> 149 config MIPS_CPS_NS16550_SHIFT
>> 150 int "UART Register Shift"
>> 151 default 0
>> 152 help
>> 153 The number of bits to shift ns16550 register indices by in order to
>> 154 form their addresses. That is, log base 2 of the span between
>> 155 adjacent ns16550 registers in the system.
>> 156
>> 157 endif # MIPS_CPS_NS16550_BOOL
>> 158
>> 159 endmenu
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