x86: initial fixmap support (b1c931e3) · Commits · 戴 / test

arch/i386/kernel/head.S

+8 −0

Original line number	Diff line number	Diff line
		@@ -168,6 +168,12 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
		.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
		@@ -507,6 +513,8 @@ ENTRY(_stext)
		.section ".bss.page_aligned","w"
		ENTRY(swapper_pg_dir)
		.fill 1024,4,0
		ENTRY(swapper_pg_pmd)
		.fill 1024,4,0
		ENTRY(empty_zero_page)
		.fill 4096,1,0

+14 −1

Original line number	Diff line number	Diff line
		@@ -73,7 +73,11 @@ startup_64:
		addq %rbp, init_level4_pgt + (511*8)(%rip)

		addq %rbp, level3_ident_pgt + 0(%rip)

		addq %rbp, level3_kernel_pgt + (510*8)(%rip)
		addq %rbp, level3_kernel_pgt + (511*8)(%rip)

		addq %rbp, level2_fixmap_pgt + (506*8)(%rip)

		/* Add an Identity mapping if I am above 1G */
		leaq _text(%rip), %rdi
		@@ -314,7 +318,16 @@ NEXT_PAGE(level3_kernel_pgt)
		.fill 510,8,0
		/* (2^48-(2102410241024)-((2^39)511))/(2^30) = 510 */
		.quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE
		.fill 1,8,0
		.quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE

		NEXT_PAGE(level2_fixmap_pgt)
		.fill 506,8,0
		.quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE
		/* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */
		.fill 5,8,0

		NEXT_PAGE(level1_fixmap_pgt)
		.fill 512,8,0

		NEXT_PAGE(level2_ident_pgt)
		/* Since I easily can, map the first 1G.