1# SPDX-License-Identifier: GPL-2.0 2menu "Kernel hacking" 3 4config TRACE_IRQFLAGS_SUPPORT 5 bool 6 default y 7 8source "lib/Kconfig.debug" 9 10config 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 24config 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 33config USE_GENERIC_EARLY_PRINTK_8250 34 bool 35 36config 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 56config 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 72config 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 83config 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 91config 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 110config 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 117config 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 127menuconfig MIPS_CPS_NS16550_BOOL 128 bool "CPS SMP NS16550 UART output" 129 depends on MIPS_CPS 130 help 131 Output debug information via an ns16550 compatible UART if exceptions 132 occur early in the boot process of a secondary core. 133 134if MIPS_CPS_NS16550_BOOL 135 136config MIPS_CPS_NS16550 137 def_bool MIPS_CPS_NS16550_BASE != 0 138 139config 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 149config 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 157endif # MIPS_CPS_NS16550_BOOL 158 159endmenu 160