]>
git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - arch/x86/boot/main.c
1 /* -*- linux-c -*- ------------------------------------------------------- *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 * Copyright 2009 Intel Corporation; author H. Peter Anvin
7 * This file is part of the Linux kernel, and is made available under
8 * the terms of the GNU General Public License version 2.
10 * ----------------------------------------------------------------------- */
13 * Main module for the real-mode kernel code
19 struct boot_params boot_params
__attribute__((aligned(16)));
22 char *heap_end
= _end
; /* Default end of heap = no heap */
25 * Copy the header into the boot parameter block. Since this
26 * screws up the old-style command line protocol, adjust by
27 * filling in the new-style command line pointer instead.
30 static void copy_boot_params(void)
36 const struct old_cmdline
* const oldcmd
=
37 (const struct old_cmdline
*)OLD_CL_ADDRESS
;
39 BUILD_BUG_ON(sizeof boot_params
!= 4096);
40 memcpy(&boot_params
.hdr
, &hdr
, sizeof hdr
);
42 if (!boot_params
.hdr
.cmd_line_ptr
&&
43 oldcmd
->cl_magic
== OLD_CL_MAGIC
) {
44 /* Old-style command line protocol. */
47 /* Figure out if the command line falls in the region
48 of memory that an old kernel would have copied up
50 if (oldcmd
->cl_offset
< boot_params
.hdr
.setup_move_size
)
55 boot_params
.hdr
.cmd_line_ptr
=
56 (cmdline_seg
<< 4) + oldcmd
->cl_offset
;
61 * Query the keyboard lock status as given by the BIOS, and
62 * set the keyboard repeat rate to maximum. Unclear why the latter
63 * is done here; this might be possible to kill off as stale code.
65 static void keyboard_init(void)
67 struct biosregs ireg
, oreg
;
70 ireg
.ah
= 0x02; /* Get keyboard status */
71 intcall(0x16, &ireg
, &oreg
);
72 boot_params
.kbd_status
= oreg
.al
;
74 ireg
.ax
= 0x0305; /* Set keyboard repeat rate */
75 intcall(0x16, &ireg
, NULL
);
79 * Get Intel SpeedStep (IST) information.
81 static void query_ist(void)
83 struct biosregs ireg
, oreg
;
85 /* Some older BIOSes apparently crash on this call, so filter
86 it from machines too old to have SpeedStep at all. */
91 ireg
.ax
= 0xe980; /* IST Support */
92 ireg
.edx
= 0x47534943; /* Request value */
93 intcall(0x15, &ireg
, &oreg
);
95 boot_params
.ist_info
.signature
= oreg
.eax
;
96 boot_params
.ist_info
.command
= oreg
.ebx
;
97 boot_params
.ist_info
.event
= oreg
.ecx
;
98 boot_params
.ist_info
.perf_level
= oreg
.edx
;
102 * Tell the BIOS what CPU mode we intend to run in.
104 static void set_bios_mode(void)
107 struct biosregs ireg
;
112 intcall(0x15, &ireg
, NULL
);
116 static void init_heap(void)
120 if (boot_params
.hdr
.loadflags
& CAN_USE_HEAP
) {
121 asm("leal %P1(%%esp),%0"
122 : "=r" (stack_end
) : "i" (-STACK_SIZE
));
125 ((size_t)boot_params
.hdr
.heap_end_ptr
+ 0x200);
126 if (heap_end
> stack_end
)
127 heap_end
= stack_end
;
129 /* Boot protocol 2.00 only, no heap available */
130 puts("WARNING: Ancient bootloader, some functionality "
131 "may be limited!\n");
137 /* First, copy the boot header into the "zeropage" */
140 /* Initialize the early-boot console */
142 if (cmdline_find_option_bool("debug"))
143 puts("early console in setup code\n");
145 /* End of heap check */
148 /* Make sure we have all the proper CPU support */
149 if (validate_cpu()) {
150 puts("Unable to boot - please use a kernel appropriate "
155 /* Tell the BIOS what CPU mode we intend to run in. */
158 /* Detect memory layout */
161 /* Set keyboard repeat rate (why?) and query the lock flags */
164 /* Query MCA information */
167 /* Query Intel SpeedStep (IST) information */
170 /* Query APM information */
171 #if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
175 /* Query EDD information */
176 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
180 /* Set the video mode */
183 /* Do the last things and invoke protected mode */
184 go_to_protected_mode();