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
e76fe57447e88916 ("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: d0380e6c3c0f6edb ("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>

diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index c449e7c1b20ff5b5e338df5baed2d0299feeef94..8bcd6c1431a95be92dffe917d1b17c6503f0a082 100644 (file)
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -22,6 +22,17 @@ config STACK_DEBUG
          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