xref: /openbmc/linux/arch/x86/kernel/head32.c (revision 95e9fd10)
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/apic.h>
18 #include <asm/io_apic.h>
19 #include <asm/bios_ebda.h>
20 #include <asm/tlbflush.h>
21 
22 static void __init i386_default_early_setup(void)
23 {
24 	/* Initialize 32bit specific setup functions */
25 	x86_init.resources.reserve_resources = i386_reserve_resources;
26 	x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
27 
28 	reserve_ebda_region();
29 }
30 
31 void __init i386_start_kernel(void)
32 {
33 	memblock_reserve(__pa_symbol(&_text),
34 			 __pa_symbol(&__bss_stop) - __pa_symbol(&_text));
35 
36 #ifdef CONFIG_BLK_DEV_INITRD
37 	/* Reserve INITRD */
38 	if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
39 		/* Assume only end is not page aligned */
40 		u64 ramdisk_image = boot_params.hdr.ramdisk_image;
41 		u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
42 		u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
43 		memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
44 	}
45 #endif
46 
47 	/* Call the subarch specific early setup function */
48 	switch (boot_params.hdr.hardware_subarch) {
49 	case X86_SUBARCH_MRST:
50 		x86_mrst_early_setup();
51 		break;
52 	case X86_SUBARCH_CE4100:
53 		x86_ce4100_early_setup();
54 		break;
55 	default:
56 		i386_default_early_setup();
57 		break;
58 	}
59 
60 	/*
61 	 * At this point everything still needed from the boot loader
62 	 * or BIOS or kernel text should be early reserved or marked not
63 	 * RAM in e820. All other memory is free game.
64 	 */
65 
66 	start_kernel();
67 }
68