xref: /openbmc/linux/arch/x86/kernel/head32.c (revision 8ac727c1)
1 /*
2  *  linux/arch/i386/kernel/head32.c -- prepare to run common code
3  *
4  *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
5  *  Copyright (C) 2007 Eric Biederman <ebiederm@xmission.com>
6  */
7 
8 #include <linux/init.h>
9 #include <linux/start_kernel.h>
10 #include <linux/mm.h>
11 #include <linux/memblock.h>
12 
13 #include <asm/setup.h>
14 #include <asm/sections.h>
15 #include <asm/e820.h>
16 #include <asm/page.h>
17 #include <asm/trampoline.h>
18 #include <asm/apic.h>
19 #include <asm/io_apic.h>
20 #include <asm/bios_ebda.h>
21 #include <asm/tlbflush.h>
22 
23 static void __init i386_default_early_setup(void)
24 {
25 	/* Initialize 32bit specific setup functions */
26 	x86_init.resources.probe_roms = probe_roms;
27 	x86_init.resources.reserve_resources = i386_reserve_resources;
28 	x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
29 
30 	reserve_ebda_region();
31 }
32 
33 void __init i386_start_kernel(void)
34 {
35 	memblock_init();
36 
37 #ifdef CONFIG_X86_TRAMPOLINE
38 	/*
39 	 * But first pinch a few for the stack/trampoline stuff
40 	 * FIXME: Don't need the extra page at 4K, but need to fix
41 	 * trampoline before removing it. (see the GDT stuff)
42 	 */
43 	memblock_x86_reserve_range(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
44 #endif
45 
46 	memblock_x86_reserve_range(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");
47 
48 #ifdef CONFIG_BLK_DEV_INITRD
49 	/* Reserve INITRD */
50 	if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
51 		/* Assume only end is not page aligned */
52 		u64 ramdisk_image = boot_params.hdr.ramdisk_image;
53 		u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
54 		u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
55 		memblock_x86_reserve_range(ramdisk_image, ramdisk_end, "RAMDISK");
56 	}
57 #endif
58 
59 	/* Call the subarch specific early setup function */
60 	switch (boot_params.hdr.hardware_subarch) {
61 	case X86_SUBARCH_MRST:
62 		x86_mrst_early_setup();
63 		break;
64 	case X86_SUBARCH_CE4100:
65 		x86_ce4100_early_setup();
66 		break;
67 	default:
68 		i386_default_early_setup();
69 		break;
70 	}
71 
72 	/*
73 	 * At this point everything still needed from the boot loader
74 	 * or BIOS or kernel text should be early reserved or marked not
75 	 * RAM in e820. All other memory is free game.
76 	 */
77 
78 	start_kernel();
79 }
80