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/*
* aboot.c
*
* This file is part of aboot, the SRM bootloader for Linux/Alpha
* Copyright (C) 1996 Linus Torvalds, David Mosberger, and Michael Schwingen.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/a.out.h>
#include <linux/elf.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/console.h>
#include <asm/hwrpb.h>
#include <asm/system.h>
#include <alloca.h>
#include <aboot.h>
#include <config.h>
#include <cons.h>
#include <setjmp.h>
#include <utils.h>
#define PASTE(x) #x
#define VERSION(maj,min) PASTE(maj) "." PASTE(min)
#ifndef elf_check_arch
# define elf_check_arch(e) 1
#endif
struct bootfs * bfs = 0; /* filesystem to boot from */
char * dest_addr = 0;
long bytes_to_copy = 0;
long text_offset = 0;
jmp_buf jump_buffer;
char kernel_args[256] = "";
unsigned long start_addr = START_ADDR;
char * bss_start = 0;
long bss_size = 0; /* size of bss */
static unsigned long entry_addr = START_ADDR;
#ifdef DEBUG
void wait_key (void)
{
while (cons_getchar() != 13) /* skip */;
}
void
test_key (void)
{
int c;
do {
c = cons_getchar();
if (c != 0) printf("%d ",c);
} while (c != 13);
}
#endif /* DEBUG */
/*
* The decompression code calls this function after decompressing the
* first block of the object file. The first block must contain all
* the relevant header information.
*/
long
first_block (const char *buf, long blocksize)
{
struct exec *aout;
struct elfhdr *elf;
struct elf_phdr *phdr;
aout = (struct exec *) buf;
elf = (struct elfhdr *) buf;
if (elf->e_ident[0] == 0x7f
&& strncmp(elf->e_ident + 1, "ELF", 3) == 0)
{
/* looks like an ELF binary: */
if (elf->e_type != ET_EXEC) {
printf("aboot: not an executable ELF file\n");
return -1;
}
if (!elf_check_arch(elf->e_machine)) {
printf("aboot: ELF executable not for this machine\n");
return -1;
}
if (elf->e_phnum != 1) {
printf("aboot: expected 1, not %d program headers\n",
elf->e_phnum);
return -1;
}
if (elf->e_phoff + sizeof(*phdr) > (unsigned) blocksize) {
printf("aboot: "
"ELF program header not in first block (%ld)\n",
(long) elf->e_phoff);
return -1;
}
phdr = (struct elf_phdr *) (buf + elf->e_phoff);
entry_addr = elf->e_entry;
start_addr = phdr->p_vaddr;
text_offset = phdr->p_offset;
bytes_to_copy = phdr->p_filesz;
bss_size = phdr->p_memsz - phdr->p_filesz;
} else if (N_MAGIC(*aout) == OMAGIC) {
/* looks like an ECOFF binary: */
entry_addr = aout->a_entry;
start_addr = N_TXTADDR(*aout);
text_offset = N_TXTOFF(*aout);
bytes_to_copy = aout->a_text + aout->a_data;
bss_size = aout->a_bss;
} else {
printf("aboot: unexpected object file format %lo\n",
N_MAGIC(*aout));
return -1;
}
if (start_addr < 0xfffffc0000000000UL
|| entry_addr < start_addr
|| entry_addr >= start_addr + bytes_to_copy)
{
printf("aboot: bad program header "
"(start=%lx, entry=%lx, size=%lx)\n",
start_addr, entry_addr, bytes_to_copy);
return -1;
}
dest_addr = (char *) start_addr;
bss_start = dest_addr + bytes_to_copy;
return 0;
}
/*
* Start the kernel.
*/
static void
run_kernel(void)
{
__asm__ __volatile__(
"bis %1,%1,$30\n\t"
"bis %0,%0,$26\n\t"
"ret ($26)"
: /* no outputs: it doesn't even return */
: "r" (entry_addr),
"r" (PAGE_SIZE + INIT_STACK));
}
/*
* Head transfers control to this function. Don't call it main() to avoid
* gcc doing magic initialization things that we don't want.
*/
void
main_ (void)
{
extern long load_kernel (void);
long i, result;
cons_init();
printf("aboot: Linux/Alpha SRM bootloader version "
VERSION(ABOOT_MAJOR, ABOOT_MINOR) "\n");
if (INIT_HWRPB->pagesize != 8192) {
printf("aboot: expected 8kB pages, got %ldkB\n",
INIT_HWRPB->pagesize >> 10);
return;
}
pal_init();
result = load_kernel();
if (result < 0) {
printf("aboot: load failed (%lx)\n", result);
return;
}
strcpy((char*)ZERO_PGE, kernel_args);
printf("aboot: ok, now starting the kernel...\n");
run_kernel();
printf("aboot: kernel returned unexpectedly. Halting slowly...\n");
for (i = 0 ; i < 0x100000000 ; i++)
/* nothing */;
halt();
}
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