linux/arch/sh/Kconfig.debug
Geert Uytterhoeven 553f7ac78f sh: bios: Revive earlyprintk support
The SuperH BIOS earlyprintk code is protected by CONFIG_EARLY_PRINTK.
However, when this protection was added, it was missed that SuperH no
longer defines an EARLY_PRINTK config symbol since commit
e76fe57447 ("sh: Remove old early serial console code V2"), so
BIOS earlyprintk can no longer be used.

Fix this by reviving the EARLY_PRINTK config symbol.

Fixes: d0380e6c3c ("early_printk: consolidate random copies of identical code")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/c40972dfec3dcc6719808d5df388857360262878.1697708489.git.geert+renesas@glider.be
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2023-10-25 16:50:30 +02:00

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# SPDX-License-Identifier: GPL-2.0
config SH_STANDARD_BIOS
bool "Use LinuxSH standard BIOS"
help
Say Y here if your target has the gdb-sh-stub
package from www.m17n.org (or any conforming standard LinuxSH BIOS)
in FLASH or EPROM. The kernel will use standard BIOS calls during
boot for various housekeeping tasks (including calls to read and
write characters to a system console, get a MAC address from an
on-board Ethernet interface, and shut down the hardware). Note this
does not work with machines with an existing operating system in
mask ROM and no flash (WindowsCE machines fall in this category).
If unsure, say N.
config STACK_DEBUG
bool "Check for stack overflows"
depends on DEBUG_KERNEL && PRINTK
help
This option will cause messages to be printed if free stack space
drops below a certain limit. Saying Y here will add overhead to
every function call and will therefore incur a major
performance hit. Most users should say N.
config EARLY_PRINTK
bool "Early printk"
depends on SH_STANDARD_BIOS
help
Say Y here to redirect kernel printk messages to the serial port
used by the SH-IPL bootloader, starting very early in the boot
process and ending when the kernel's serial console is initialised.
This option is only useful while porting the kernel to a new machine,
when the kernel may crash or hang before the serial console is
initialised. If unsure, say N.
config 4KSTACKS
bool "Use 4Kb for kernel stacks instead of 8Kb"
depends on DEBUG_KERNEL && (MMU || BROKEN) && !PAGE_SIZE_64KB
help
If you say Y here the kernel will use a 4Kb stacksize for the
kernel stack attached to each process/thread. This facilitates
running more threads on a system and also reduces the pressure
on the VM subsystem for higher order allocations. This option
will also use IRQ stacks to compensate for the reduced stackspace.
config IRQSTACKS
bool "Use separate kernel stacks when processing interrupts"
depends on DEBUG_KERNEL && BROKEN
help
If you say Y here the kernel will use separate kernel stacks
for handling hard and soft interrupts. This can help avoid
overflowing the process kernel stacks.
config DUMP_CODE
bool "Show disassembly of nearby code in register dumps"
depends on DEBUG_KERNEL
default y if DEBUG_BUGVERBOSE
default n
help
This prints out a code trace of the instructions leading up to
the faulting instruction as a debugging aid. As this does grow
the kernel in size a bit, most users will want to say N here.
Those looking for more verbose debugging output should say Y.
config DWARF_UNWINDER
bool "Enable the DWARF unwinder for stacktraces"
depends on DEBUG_KERNEL
select FRAME_POINTER
default n
help
Enabling this option will make stacktraces more accurate, at
the cost of an increase in overall kernel size.
config SH_NO_BSS_INIT
bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)"
depends on DEBUG_KERNEL
default n
help
If running in painfully slow environments, such as an RTL
simulation or from remote memory via SHdebug, where the memory
can already be guaranteed to ber zeroed on boot, say Y.
For all other cases, say N. If this option seems perplexing, or
you aren't sure, say N.
config MCOUNT
def_bool y
depends on STACK_DEBUG || FUNCTION_TRACER