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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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8fee13a48e
This enables the decompressor output to be seen on the serial console. Most of the code is shared with the regular boot code. We could add printf to the decompressor if needed, but currently there is no sufficiently compelling user. -v2: define BOOT_BOOT_H to avoid include boot.h -v3: early_serial_base need to be static in misc.c ? -v4: create seperate string.c printf.c cmdline.c early_serial_console.c after hpa's patch that allow global variables in compressed/misc stage -v5: remove printf.c related Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
179 lines
4.1 KiB
C
179 lines
4.1 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright 2007 rPath, Inc. - All Rights Reserved
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* Copyright 2009 Intel Corporation; author H. Peter Anvin
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*
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* This file is part of the Linux kernel, and is made available under
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* the terms of the GNU General Public License version 2.
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*
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* ----------------------------------------------------------------------- */
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/*
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* Main module for the real-mode kernel code
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*/
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#include "boot.h"
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struct boot_params boot_params __attribute__((aligned(16)));
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char *HEAP = _end;
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char *heap_end = _end; /* Default end of heap = no heap */
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/*
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* Copy the header into the boot parameter block. Since this
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* screws up the old-style command line protocol, adjust by
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* filling in the new-style command line pointer instead.
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*/
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static void copy_boot_params(void)
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{
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struct old_cmdline {
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u16 cl_magic;
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u16 cl_offset;
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};
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const struct old_cmdline * const oldcmd =
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(const struct old_cmdline *)OLD_CL_ADDRESS;
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BUILD_BUG_ON(sizeof boot_params != 4096);
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memcpy(&boot_params.hdr, &hdr, sizeof hdr);
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if (!boot_params.hdr.cmd_line_ptr &&
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oldcmd->cl_magic == OLD_CL_MAGIC) {
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/* Old-style command line protocol. */
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u16 cmdline_seg;
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/* Figure out if the command line falls in the region
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of memory that an old kernel would have copied up
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to 0x90000... */
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if (oldcmd->cl_offset < boot_params.hdr.setup_move_size)
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cmdline_seg = ds();
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else
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cmdline_seg = 0x9000;
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boot_params.hdr.cmd_line_ptr =
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(cmdline_seg << 4) + oldcmd->cl_offset;
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}
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}
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/*
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* Set the keyboard repeat rate to maximum. Unclear why this
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* is done here; this might be possible to kill off as stale code.
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*/
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static void keyboard_set_repeat(void)
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{
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struct biosregs ireg;
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initregs(&ireg);
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ireg.ax = 0x0305;
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intcall(0x16, &ireg, NULL);
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}
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/*
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* Get Intel SpeedStep (IST) information.
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*/
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static void query_ist(void)
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{
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struct biosregs ireg, oreg;
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/* Some older BIOSes apparently crash on this call, so filter
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it from machines too old to have SpeedStep at all. */
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if (cpu.level < 6)
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return;
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initregs(&ireg);
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ireg.ax = 0xe980; /* IST Support */
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ireg.edx = 0x47534943; /* Request value */
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intcall(0x15, &ireg, &oreg);
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boot_params.ist_info.signature = oreg.eax;
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boot_params.ist_info.command = oreg.ebx;
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boot_params.ist_info.event = oreg.ecx;
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boot_params.ist_info.perf_level = oreg.edx;
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}
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/*
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* Tell the BIOS what CPU mode we intend to run in.
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*/
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static void set_bios_mode(void)
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{
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#ifdef CONFIG_X86_64
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struct biosregs ireg;
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initregs(&ireg);
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ireg.ax = 0xec00;
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ireg.bx = 2;
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intcall(0x15, &ireg, NULL);
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#endif
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}
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static void init_heap(void)
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{
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char *stack_end;
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if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
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asm("leal %P1(%%esp),%0"
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: "=r" (stack_end) : "i" (-STACK_SIZE));
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heap_end = (char *)
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((size_t)boot_params.hdr.heap_end_ptr + 0x200);
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if (heap_end > stack_end)
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heap_end = stack_end;
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} else {
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/* Boot protocol 2.00 only, no heap available */
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puts("WARNING: Ancient bootloader, some functionality "
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"may be limited!\n");
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}
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}
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void main(void)
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{
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/* First, copy the boot header into the "zeropage" */
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copy_boot_params();
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/* Initialize the early-boot console */
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console_init();
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if (cmdline_find_option_bool("debug"))
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puts("early console in setup code\n");
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/* End of heap check */
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init_heap();
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/* Make sure we have all the proper CPU support */
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if (validate_cpu()) {
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puts("Unable to boot - please use a kernel appropriate "
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"for your CPU.\n");
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die();
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}
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/* Tell the BIOS what CPU mode we intend to run in. */
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set_bios_mode();
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/* Detect memory layout */
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detect_memory();
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/* Set keyboard repeat rate (why?) */
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keyboard_set_repeat();
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/* Query MCA information */
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query_mca();
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/* Query Intel SpeedStep (IST) information */
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query_ist();
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/* Query APM information */
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#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
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query_apm_bios();
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#endif
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/* Query EDD information */
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#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
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query_edd();
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#endif
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/* Set the video mode */
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set_video();
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/* Do the last things and invoke protected mode */
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go_to_protected_mode();
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}
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