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/*
* bootstub 32 bit entry setting routings
* Copyright (C) 2008, Alek Du <alek.du@intel.com> Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include "types.h"
#include "bootstub.h"
#include "bootparam.h"
#include "spi-uart.h"
#define bs_printk(x) { if (! *(int *)SPI_UART_SUPPRESSION) bs_spi_printk(x);}
struct gdt_ptr {
u16 len;
u32 ptr;
} __attribute__((packed));
static void setup_gdt(void)
{
static const u64 boot_gdt[] __attribute__((aligned(16))) = {
/* CS: code, read/execute, 4 GB, base 0 */
[GDT_ENTRY_BOOT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
/* DS: data, read/write, 4 GB, base 0 */
[GDT_ENTRY_BOOT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
};
static struct gdt_ptr gdt;
gdt.len = sizeof(boot_gdt)-1;
gdt.ptr = (u32)&boot_gdt;
asm volatile("lgdtl %0" : : "m" (gdt));
}
static void setup_idt(void)
{
static const struct gdt_ptr null_idt = {0, 0};
asm volatile("lidtl %0" : : "m" (null_idt));
}
static void *memcpy(void *dest, const void *src, size_t count)
{
char *tmp = dest;
const char *s = src;
while (count--)
*tmp++ = *s++;
return dest;
}
static void *memset(void *s, int c, size_t count)
{
char *xs = s;
while (count--)
*xs++ = c;
return s;
}
static size_t strnlen(const char *s, size_t maxlen)
{
const char *es = s;
while (*es && maxlen) {
es++;
maxlen--;
}
return (es - s);
}
static void setup_boot_params(struct boot_params *bp, struct setup_header *sh)
{
memset(bp, 0, sizeof (struct boot_params));
bp->screen_info.orig_video_mode = 0;
bp->screen_info.orig_video_lines = 0;
bp->screen_info.orig_video_cols = 0;
bp->alt_mem_k = 128*1024; // hard coded 128M mem here, since SFI will override it
memcpy(&bp->hdr, sh, sizeof (struct setup_header));
bp->hdr.cmd_line_ptr = CMDLINE_OFFSET;
bp->hdr.cmdline_size = strnlen((const char *)CMDLINE_OFFSET,256);
bp->hdr.type_of_loader = 0xff; //bootstub is unknown bootloader for kernel :)
bp->hdr.ramdisk_size = *(u32 *)INITRD_SIZE_OFFSET;
bp->hdr.ramdisk_image = (bp->alt_mem_k*1024 - bp->hdr.ramdisk_size) & 0xFFFFF000;
bp->hdr.hardware_subarch = X86_SUBARCH_MRST;
memcpy((u8*)bp->hdr.ramdisk_image, (u8 *)BZIMAGE_OFFSET + *(u32 *)BZIMAGE_SIZE_OFFSET, bp->hdr.ramdisk_size);
}
static int get_32bit_entry(unsigned char *ptr)
{
while (1){
if (*(u32 *)ptr == SETUP_SIGNATURE && *(u32 *)(ptr+4) == 0)
break;
ptr++;
}
ptr+=4;
return (((unsigned int)ptr+511)/512)*512;
}
int bootstub(void)
{
setup_idt();
setup_gdt();
bs_printk("Bootstub Version: 0.4 ...\n");
setup_boot_params((struct boot_params *)BOOT_PARAMS_OFFSET,
(struct setup_header *)SETUP_HEADER_OFFSET);
return get_32bit_entry((unsigned char *)BZIMAGE_OFFSET);
}
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