Commit 076f9776 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86: make early printk selectable on 64-bit as well 



Enable CONFIG_EMBEDDED to select CONFIG_EARLY_PRINTK on 64-bit as well.

saves ~2K:

   text    data     bss     dec     hex filename
   7290283 3672091 1907848 12870222         c4624e vmlinux.before
   7288373 3671795 1907848 12868016         c459b0 vmlinux.after

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 8866cd9d

arch/x86/Kconfig.debug

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ config TRACE_IRQFLAGS_SUPPORT 
source "lib/Kconfig.debug"



config EARLY_PRINTK

	bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32

	bool "Early printk" if EMBEDDED

	default y

	help

	  Write kernel log output directly into the VGA buffer or to a serial

arch/x86/kernel/head64.c

+6 −1
Original line number Diff line number Diff line
@@ -58,8 +58,13 @@ void __init x86_64_start_kernel(char * real_mode_data) 
	/* Make NULL pointers segfault */

	zap_identity_mappings();



	for (i = 0; i < IDT_ENTRIES; i++)

	for (i = 0; i < IDT_ENTRIES; i++) {

#ifdef CONFIG_EARLY_PRINTK

		set_intr_gate(i, &early_idt_handlers[i]);

#else

		set_intr_gate(i, early_idt_handler);

#endif

	}

	load_idt((const struct desc_ptr *)&idt_descr);



	early_printk("Kernel alive\n");

arch/x86/kernel/head_64.S

+7 −0
Original line number Diff line number Diff line
@@ -267,6 +267,7 @@ init_rsp: 
bad_address:

	jmp bad_address



#ifdef CONFIG_EARLY_PRINTK

.macro early_idt_tramp first, last

	.ifgt \last-\first

	early_idt_tramp \first, \last-1
@@ -281,8 +282,10 @@ early_idt_handlers: 
	early_idt_tramp 64, 127

	early_idt_tramp 128, 191

	early_idt_tramp 192, 255

#endif



ENTRY(early_idt_handler)

#ifdef CONFIG_EARLY_PRINTK

	cmpl $2,early_recursion_flag(%rip)

	jz  1f

	incl early_recursion_flag(%rip)
@@ -311,8 +314,11 @@ ENTRY(early_idt_handler) 
	movq 8(%rsp),%rsi	# get rip again

	call __print_symbol

#endif

#endif /* EARLY_PRINTK */

1:	hlt

	jmp 1b



#ifdef CONFIG_EARLY_PRINTK

early_recursion_flag:

	.long 0
@@ -320,6 +326,7 @@ early_idt_msg: 
	.asciz "PANIC: early exception %02lx rip %lx:%lx error %lx cr2 %lx\n"

early_idt_ripmsg:

	.asciz "RIP %s\n"

#endif /* CONFIG_EARLY_PRINTK */



.balign PAGE_SIZE

include/asm-x86/kdebug.h

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ enum die_val { 
	DIE_PAGE_FAULT,

};



extern void early_printk(const char *fmt, ...) __attribute__((format(printf,1,2)));

extern void printk_address(unsigned long address);

extern void die(const char *,struct pt_regs *,long);

extern int __must_check __die(const char *, struct pt_regs *, long);

include/linux/kernel.h

+3 −0
Original line number Diff line number Diff line
@@ -194,6 +194,9 @@ static inline int log_buf_read(int idx) { return 0; } 
static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }

#endif



extern void __attribute__((format(printf, 1, 2)))

	early_printk(const char *fmt, ...);



unsigned long int_sqrt(unsigned long);



extern int printk_ratelimit(void);

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