2 # For a description of the syntax of this configuration file,
3 # see Linux's Documentation/kbuild/kconfig-language.txt.
5 mainmenu "Akaros/$SRCARCH Kernel Configuration"
7 # This is info, not a setable option. Must make ARCH=arch to change.
16 Say yes to build a 64-bit kernel, amd64 / x86_64, riscv64, etc.
18 source "kern/arch/$SRCARCH/Kconfig"
20 source "kern/src/net/Kconfig"
22 source "kern/drivers/Kconfig"
30 KFS is an initramfs bundled into the kernel, and contains your root
35 string "KFS/Initramfs paths"
38 Space separated list of paths to directories to bundle into KFS. This
39 will be your root filesystem.
43 string "KFS CPIO helper"
46 This binary (relative to the root directory) will be run before
47 bundling the KFS Paths into the CPIO.
50 bool "Ext2 filesystem"
53 Build in support for ext2. Extremely experimental, and only works with
54 a block device image, which will be mounted at /mnt. If you select
55 this, you must specify a block device.
59 string "Ext2 image file"
60 default mnt/ext2fs.img
62 This file needs to be an ext2 image (file that looks like a block
63 device). You should be able to mount this file in your host OS. It
64 will be bundled into the kernel and mounted at /mnt.
68 menu "Memory Management"
74 Turns on internal support for page coloring. When turned off, the page
75 allocator acts like there is only one color. Hasn't been used in a few
79 depends on PAGE_COLORING
80 bool "Boxboro-specific page coloring"
87 menu "Kernel Debugging"
89 menu "Per-cpu Tracers"
95 Turns on KMSG tracing, using the per-cpu ring buffer (holds about 256
96 events). You can access this from the monitor via "trace pcpui". Turn
97 this off for a slight performance improvement on every KMSG (and every
102 depends on SPINLOCK_DEBUG
105 Turns on lock tracing, using the per-cpu ring buffer. This records the
106 a timestamp and lock address, in an over-write tracing style (meaning
107 it'll clobber older events). If you have locking issues, this may give
108 you clues as to which locks were grabbed recently.
112 config SPINLOCK_DEBUG
113 bool "Spinlock debugging"
116 Turns on debugging, which tracks the last time a lock was acquired and
117 detects improper lock acquisition based on IRQ levels (e.g. using
118 spin_lock() in IRQ context). This will slow down all lock
122 bool "Seqlock debugging"
125 Provides asserts to detect seqlock errors. This will allow a malicious
126 userspace to trigger a panic in the kernel.
128 config SEMAPHORE_DEBUG
129 bool "Semaphore debugging"
132 Turns on debugging, which tracks the last time and location that a
133 semaphore was downed, and provides a linked list of all semaphores that
134 have waiters. This will slow down all semaphore ups and downs.
140 When idling, the kernel will reset the stack of its kernel thread to
141 the top of the stack, abandoning its context. This is useful so we do
142 not run off the end of our stacks, but makes backtracing difficult.
144 config KTHREAD_POISON
145 bool "Kthread Poison Canary"
148 Kthreads will use a bit of storage at the bottom of the stack to track
149 the state of the kthread. This is useful to catch various bugs with
150 kthreading, such as launching the same kthread twice concurrently.
153 bool "Disables symmetric multithreading"
156 Disables hyperthreading by telling the kernel to never give out even
157 numbered cores to MCPs. This does not check to see if the threads are
158 in fact siblings, or if the target machine is hyperthreaded.
160 config PRINTK_NO_BACKSPACE
161 bool "Printk with no backspace"
164 One of the serial devices I was using a while back had issues printing
165 backspaces. This was an old hack to deal with that.
169 menu "Misc/Old Options"
172 bool "Asynchronous remote syscalls"
175 Code to run a syscall-server on a core. A process can submit syscalls
176 and get the results asynchronously. Hasn't been used in years. Say
177 'n' unless you want to play around.
179 # SPARC auto-selects this
184 Old school I/O was through a remote machine. Not sure if anyone uses
191 Like the appserver, serial I/O was an old attempt to process I/O on a
192 remote machine across the serial port.
198 Have the kernel boot only a single core. Can be useful for debugging,
199 but hasn't been used in years.
205 This was an old joke. Say 'n', since we can't simply #include <bsd>.