Commit 17d57a92 authored Dec 01, 2007 by Eric W. Biederman Committed by Ingo Molnar Dec 03, 2007

x86: fix x86-32 early fixmap initialization.

pageexec@freemail.hu writes:

> i've just noticed that the chunk in i386/kernel/head.S ended up in a
> weird place, namely, it's not going to be executed as it's just after
> a 'jmp 3f' and before startup_32_smp, probably not what you intended.
> on a sidenote, the whole thing can be done in a single insn, like:
>
> movl $(swapper_pg_pmd - __PAGE_OFFSET + 0x067), (swapper_pg_dir -
> __PAGE_OFFSET+ 4092)

Thanks for the reminder I thought we had fixed this problem a while ago.

Needed to get fixed virtual address for USB debug and earlycon with mmio.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 0c1b2724

arch/x86/kernel/head_32.S

+6 −6

Original line number	Diff line number	Diff line
		@@ -193,6 +193,12 @@ default_entry:
		jb 10b
		movl %edi,(init_pg_tables_end - __PAGE_OFFSET)

		/* Do an early initialization of the fixmap area */
		movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
		movl $(swapper_pg_pmd - __PAGE_OFFSET), %eax
		addl $0x007, %eax /* 0x007 = PRESENT+RW+USER */
		movl %eax, 4092(%edx)

		xorl %ebx,%ebx /* This is the boot CPU (BSP) */
		jmp 3f
		/*
		@@ -208,12 +214,6 @@ default_entry:
		.section .init.text,"ax",@progbits
		#endif

		/* Do an early initialization of the fixmap area */
		movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
		movl $(swapper_pg_pmd - __PAGE_OFFSET), %eax
		addl $0x007, %eax /* 0x007 = PRESENT+RW+USER */
		movl %eax, 4092(%edx)

		#ifdef CONFIG_SMP
		ENTRY(startup_32_smp)
		cld