[coreboot-gerrit] Patch set updated for coreboot: 0deabe2 console: Squelch console output from AP CPUs in romstage
Kyösti Mälkki (kyosti.malkki@gmail.com)
gerrit at coreboot.org
Tue Aug 13 15:48:37 CEST 2013
Kyösti Mälkki (kyosti.malkki at gmail.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3854
-gerrit
commit 0deabe2e57e3f13fcc46654bf5af30627cea1a12
Author: Kyösti Mälkki <kyosti.malkki at gmail.com>
Date: Mon Aug 12 23:29:57 2013 +0300
console: Squelch console output from AP CPUs in romstage
Add Kconfig option SQUELCH_EARLY_SMP and have it enabled by
default.
Console drivers have unpredictable results if multiple threads
attempt to share same resources without spinlock. Serial UARTs
have not had huge problems, only distorted output, but those
relying on cache-as-ram (CBMEM and usbdebug) may require this.
Change-Id: I7f406fdea7b6dc6a341c4da2fab56f7b7ff568b4
Signed-off-by: Kyösti Mälkki <kyosti.malkki at gmail.com>
---
src/arch/x86/lib/romstage_console.c | 9 ++++++++-
src/console/Kconfig | 12 ++++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/src/arch/x86/lib/romstage_console.c b/src/arch/x86/lib/romstage_console.c
index 2e743ad..1c3141c 100644
--- a/src/arch/x86/lib/romstage_console.c
+++ b/src/arch/x86/lib/romstage_console.c
@@ -31,7 +31,9 @@
#if CONFIG_SPKMODEM
#include <console/spkmodem.h>
#endif
-
+#if CONFIG_SQUELCH_EARLY_SMP
+#include <cpu/x86/lapic.h>
+#endif
void console_tx_byte(unsigned char byte)
{
@@ -86,6 +88,11 @@ int do_printk(int msg_level, const char *fmt, ...)
return 0;
}
+#if CONFIG_SQUELCH_EARLY_SMP
+ if (!boot_cpu())
+ return 0;
+#endif
+
va_start(args, fmt);
i = vtxprintf(console_tx_byte, fmt, args);
va_end(args);
diff --git a/src/console/Kconfig b/src/console/Kconfig
index 1d050f7..c5e5f28 100644
--- a/src/console/Kconfig
+++ b/src/console/Kconfig
@@ -14,6 +14,18 @@ config EARLY_CONSOLE
help
Use console during early (pre-RAM) boot stages
+config SQUELCH_EARLY_SMP
+ bool "Squelch AP CPUs from early console."
+ default y
+ depends on EARLY_CONSOLE
+ help
+ When selected only the BSP CPU will output to early console.
+
+ Console drivers have unpredictable behaviour if multiple threads
+ attempt to share the same resources without a spinlock.
+
+ If unsure, say Y.
+
config CONSOLE_SERIAL
bool "Serial port console output"
default y
More information about the coreboot-gerrit
mailing list