Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / x86 / boot / main.c

diff --git a/kernel/arch/x86/boot/main.c b/kernel/arch/x86/boot/main.c
new file mode 100644 (file)
index 0000000..fd6c9f2
--- /dev/null
+++ b/kernel/arch/x86/boot/main.c
@@ -0,0 +1,185 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright (C) 1991, 1992 Linus Torvalds
+ *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Main module for the real-mode kernel code
+ */
+
+#include "boot.h"
+#include "string.h"
+
+struct boot_params boot_params __attribute__((aligned(16)));
+
+char *HEAP = _end;
+char *heap_end = _end;         /* Default end of heap = no heap */
+
+/*
+ * Copy the header into the boot parameter block.  Since this
+ * screws up the old-style command line protocol, adjust by
+ * filling in the new-style command line pointer instead.
+ */
+
+static void copy_boot_params(void)
+{
+       struct old_cmdline {
+               u16 cl_magic;
+               u16 cl_offset;
+       };
+       const struct old_cmdline * const oldcmd =
+               (const struct old_cmdline *)OLD_CL_ADDRESS;
+
+       BUILD_BUG_ON(sizeof boot_params != 4096);
+       memcpy(&boot_params.hdr, &hdr, sizeof hdr);
+
+       if (!boot_params.hdr.cmd_line_ptr &&
+           oldcmd->cl_magic == OLD_CL_MAGIC) {
+               /* Old-style command line protocol. */
+               u16 cmdline_seg;
+
+               /* Figure out if the command line falls in the region
+                  of memory that an old kernel would have copied up
+                  to 0x90000... */
+               if (oldcmd->cl_offset < boot_params.hdr.setup_move_size)
+                       cmdline_seg = ds();
+               else
+                       cmdline_seg = 0x9000;
+
+               boot_params.hdr.cmd_line_ptr =
+                       (cmdline_seg << 4) + oldcmd->cl_offset;
+       }
+}
+
+/*
+ * Query the keyboard lock status as given by the BIOS, and
+ * set the keyboard repeat rate to maximum.  Unclear why the latter
+ * is done here; this might be possible to kill off as stale code.
+ */
+static void keyboard_init(void)
+{
+       struct biosregs ireg, oreg;
+       initregs(&ireg);
+
+       ireg.ah = 0x02;         /* Get keyboard status */
+       intcall(0x16, &ireg, &oreg);
+       boot_params.kbd_status = oreg.al;
+
+       ireg.ax = 0x0305;       /* Set keyboard repeat rate */
+       intcall(0x16, &ireg, NULL);
+}
+
+/*
+ * Get Intel SpeedStep (IST) information.
+ */
+static void query_ist(void)
+{
+       struct biosregs ireg, oreg;
+
+       /* Some older BIOSes apparently crash on this call, so filter
+          it from machines too old to have SpeedStep at all. */
+       if (cpu.level < 6)
+               return;
+
+       initregs(&ireg);
+       ireg.ax  = 0xe980;       /* IST Support */
+       ireg.edx = 0x47534943;   /* Request value */
+       intcall(0x15, &ireg, &oreg);
+
+       boot_params.ist_info.signature  = oreg.eax;
+       boot_params.ist_info.command    = oreg.ebx;
+       boot_params.ist_info.event      = oreg.ecx;
+       boot_params.ist_info.perf_level = oreg.edx;
+}
+
+/*
+ * Tell the BIOS what CPU mode we intend to run in.
+ */
+static void set_bios_mode(void)
+{
+#ifdef CONFIG_X86_64
+       struct biosregs ireg;
+
+       initregs(&ireg);
+       ireg.ax = 0xec00;
+       ireg.bx = 2;
+       intcall(0x15, &ireg, NULL);
+#endif
+}
+
+static void init_heap(void)
+{
+       char *stack_end;
+
+       if (boot_params.hdr.loadflags & CAN_USE_HEAP) {
+               asm("leal %P1(%%esp),%0"
+                   : "=r" (stack_end) : "i" (-STACK_SIZE));
+
+               heap_end = (char *)
+                       ((size_t)boot_params.hdr.heap_end_ptr + 0x200);
+               if (heap_end > stack_end)
+                       heap_end = stack_end;
+       } else {
+               /* Boot protocol 2.00 only, no heap available */
+               puts("WARNING: Ancient bootloader, some functionality "
+                    "may be limited!\n");
+       }
+}
+
+void main(void)
+{
+       /* First, copy the boot header into the "zeropage" */
+       copy_boot_params();
+
+       /* Initialize the early-boot console */
+       console_init();
+       if (cmdline_find_option_bool("debug"))
+               puts("early console in setup code\n");
+
+       /* End of heap check */
+       init_heap();
+
+       /* Make sure we have all the proper CPU support */
+       if (validate_cpu()) {
+               puts("Unable to boot - please use a kernel appropriate "
+                    "for your CPU.\n");
+               die();
+       }
+
+       /* Tell the BIOS what CPU mode we intend to run in. */
+       set_bios_mode();
+
+       /* Detect memory layout */
+       detect_memory();
+
+       /* Set keyboard repeat rate (why?) and query the lock flags */
+       keyboard_init();
+
+       /* Query MCA information */
+       query_mca();
+
+       /* Query Intel SpeedStep (IST) information */
+       query_ist();
+
+       /* Query APM information */
+#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
+       query_apm_bios();
+#endif
+
+       /* Query EDD information */
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+       query_edd();
+#endif
+
+       /* Set the video mode */
+       set_video();
+
+       /* Do the last things and invoke protected mode */
+       go_to_protected_mode();
+}