2015-04-06 11:03:12

by Alexander Kuleshov

[permalink] [raw]
Subject: [PATCH RFC] x86/boot, earlyprintk: do not compile early_setup_console if !CONFIG_EARLY_PRINTK

There is the call of the console_init() function in the arch/x86/boot/main.c
which tries to find 'earlyprintk' option in the kernel command line. This
function called every time regardless of the CONFIG_EARLY_PRINTK, but we
no need in it if CONFIG_EARLY_PRINTK is not set.

Signed-off-by: Alexander Kuleshov <[email protected]>
---
arch/x86/boot/Makefile | 6 +++---
arch/x86/boot/boot.h | 6 ++++++
arch/x86/boot/early_serial_console.c | 2 ++
arch/x86/boot/tty.c | 6 ++++--
4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 57bbf2f..e21ebc8 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -23,10 +23,10 @@ targets += fdimage fdimage144 fdimage288 image.iso mtools.conf
subdir- := compressed

setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o
-setup-y += early_serial_console.o edd.o header.o main.o mca.o memory.o
-setup-y += pm.o pmjump.o printf.o regs.o string.o tty.o video.o
-setup-y += video-mode.o version.o
+setup-y += edd.o header.o main.o mca.o memory.o pm.o pmjump.o printf.o
+setup-y += regs.o string.o tty.o video.o video-mode.o version.o
setup-$(CONFIG_X86_APM_BOOT) += apm.o
+setup-$(CONFIG_EARLY_PRINTK) += early_serial_console.o

# The link order of the video-*.o modules can matter. In particular,
# video-vga.o *must* be listed first, followed by video-vesa.o.
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index bd49ec6..5c353d2 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -297,9 +297,15 @@ static inline int cmdline_find_option_bool(const char *option)
int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr);
int validate_cpu(void);

+#ifdef CONFIG_EARLY_PRINTK
/* early_serial_console.c */
extern int early_serial_base;
void console_init(void);
+#else
+static const int early_serial_base;
+static inline void console_init(void)
+{ }
+#endif

/* edd.c */
void query_edd(void);
diff --git a/arch/x86/boot/early_serial_console.c b/arch/x86/boot/early_serial_console.c
index 45a0768..5c8e9f8 100644
--- a/arch/x86/boot/early_serial_console.c
+++ b/arch/x86/boot/early_serial_console.c
@@ -1,5 +1,7 @@
#include "boot.h"

+int early_serial_base;
+
#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */

#define DLAB 0x80
diff --git a/arch/x86/boot/tty.c b/arch/x86/boot/tty.c
index def2451..b5bd9d7 100644
--- a/arch/x86/boot/tty.c
+++ b/arch/x86/boot/tty.c
@@ -15,8 +15,6 @@

#include "boot.h"

-int early_serial_base;
-
#define XMTRDY 0x20

#define TXR 0 /* Transmit register (WRITE) */
@@ -27,6 +25,7 @@ int early_serial_base;
* error during initialization.
*/

+#ifdef CONFIG_EARLY_PRINTK
static void __attribute__((section(".inittext"))) serial_putchar(int ch)
{
unsigned timeout = 0xffff;
@@ -36,6 +35,7 @@ static void __attribute__((section(".inittext"))) serial_putchar(int ch)

outb(ch, early_serial_base + TXR);
}
+#endif

static void __attribute__((section(".inittext"))) bios_putchar(int ch)
{
@@ -56,8 +56,10 @@ void __attribute__((section(".inittext"))) putchar(int ch)

bios_putchar(ch);

+#ifdef CONFIG_EARLY_PRINTK
if (early_serial_base != 0)
serial_putchar(ch);
+#endif
}

void __attribute__((section(".inittext"))) puts(const char *str)
--
2.3.3.611.g09038fc.dirty