arch/ia64/hp/sim/boot/bootloader.c

   1 /*
   2  * arch/ia64/hp/sim/boot/bootloader.c
   3  *
   4  * Loads an ELF kernel.
   5  *
   6  * Copyright (C) 1998-2003 Hewlett-Packard Co
   7  *      David Mosberger-Tang <davidm@hpl.hp.com>
   8  *      Stephane Eranian <eranian@hpl.hp.com>
   9  *
  10  * 01/07/99 S.Eranian modified to pass command line arguments to kernel
  11  */
  12 struct task_struct;     /* forward declaration for elf.h */
  13
  14 #include <linux/elf.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17
  18 #include <asm/elf.h>
  19 #include <asm/intrinsics.h>
  20 #include <asm/pal.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/sal.h>
  23 #include <asm/system.h>
  24
  25 #include "ssc.h"
  26
  27 struct disk_req {
  28         unsigned long addr;
  29         unsigned len;
  30 };
  31
  32 struct disk_stat {
  33         int fd;
  34         unsigned count;
  35 };
  36
  37 extern void jmp_to_kernel (unsigned long bp, unsigned long e_entry);
  38 extern struct ia64_boot_param *sys_fw_init (const char *args, int arglen);
  39 extern void debug_break (void);
  40
  41 static void
  42 cons_write (const char *buf)
  43 {
  44         unsigned long ch;
  45
  46         while ((ch = *buf++) != '\0') {
  47                 ssc(ch, 0, 0, 0, SSC_PUTCHAR);
  48                 if (ch == '\n')
  49                   ssc('\r', 0, 0, 0, SSC_PUTCHAR);
  50         }
  51 }
  52
  53 #define MAX_ARGS 32
  54
  55 void
  56 start_bootloader (void)
  57 {
  58         static char mem[4096];
  59         static char buffer[1024];
  60         unsigned long off;
  61         int fd, i;
  62         struct disk_req req;
  63         struct disk_stat stat;
  64         struct elfhdr *elf;
  65         struct elf_phdr *elf_phdr;      /* program header */
  66         unsigned long e_entry, e_phoff, e_phnum;
  67         register struct ia64_boot_param *bp;
  68         char *kpath, *args;
  69         long arglen = 0;
  70
  71         ssc(0, 0, 0, 0, SSC_CONSOLE_INIT);
  72
  73         /*
  74          * S.Eranian: extract the commandline argument from the simulator
  75          *
  76          * The expected format is as follows:
  77          *
  78          *      kernelname args...
  79          *
  80          * Both are optional but you can't have the second one without the first.
  81          */
  82         arglen = ssc((long) buffer, 0, 0, 0, SSC_GET_ARGS);
  83
  84         kpath = "vmlinux";
  85         args = buffer;
  86         if (arglen > 0) {
  87                 kpath = buffer;
  88                 while (*args != ' ' && *args != '\0')
  89                         ++args, --arglen;
  90                 if (*args == ' ')
  91                         *args++ = '\0', --arglen;
  92         }
  93
  94         if (arglen <= 0) {
  95                 args = "";
  96                 arglen = 1;
  97         }
  98
  99         fd = ssc((long) kpath, 1, 0, 0, SSC_OPEN);
 100
 101         if (fd < 0) {
 102                 cons_write(kpath);
 103                 cons_write(": file not found, reboot now\n");
 104                 for(;;);
 105         }
 106         stat.fd = fd;
 107         off = 0;
 108
 109         req.len = sizeof(mem);
 110         req.addr = (long) mem;
 111         ssc(fd, 1, (long) &req, off, SSC_READ);
 112         ssc((long) &stat, 0, 0, 0, SSC_WAIT_COMPLETION);
 113
 114         elf = (struct elfhdr *) mem;
 115         if (elf->e_ident[0] == 0x7f && strncmp(elf->e_ident + 1, "ELF", 3) != 0) {
 116                 cons_write("not an ELF file\n");
 117                 return;
 118         }
 119         if (elf->e_type != ET_EXEC) {
 120                 cons_write("not an ELF executable\n");
 121                 return;
 122         }
 123         if (!elf_check_arch(elf)) {
 124                 cons_write("kernel not for this processor\n");
 125                 return;
 126         }
 127
 128         e_entry = elf->e_entry;
 129         e_phnum = elf->e_phnum;
 130         e_phoff = elf->e_phoff;
 131
 132         cons_write("loading ");
 133         cons_write(kpath);
 134         cons_write("...\n");
 135
 136         for (i = 0; i < e_phnum; ++i) {
 137                 req.len = sizeof(*elf_phdr);
 138                 req.addr = (long) mem;
 139                 ssc(fd, 1, (long) &req, e_phoff, SSC_READ);
 140                 ssc((long) &stat, 0, 0, 0, SSC_WAIT_COMPLETION);
 141                 if (stat.count != sizeof(*elf_phdr)) {
 142                         cons_write("failed to read phdr\n");
 143                         return;
 144                 }
 145                 e_phoff += sizeof(*elf_phdr);
 146
 147                 elf_phdr = (struct elf_phdr *) mem;
 148
 149                 if (elf_phdr->p_type != PT_LOAD)
 150                         continue;
 151
 152                 req.len = elf_phdr->p_filesz;
 153                 req.addr = __pa(elf_phdr->p_paddr);
 154                 ssc(fd, 1, (long) &req, elf_phdr->p_offset, SSC_READ);
 155                 ssc((long) &stat, 0, 0, 0, SSC_WAIT_COMPLETION);
 156                 memset((char *)__pa(elf_phdr->p_paddr) + elf_phdr->p_filesz, 0,
 157                        elf_phdr->p_memsz - elf_phdr->p_filesz);
 158         }
 159         ssc(fd, 0, 0, 0, SSC_CLOSE);
 160
 161         cons_write("starting kernel...\n");
 162
 163         /* fake an I/O base address: */
 164         ia64_setreg(_IA64_REG_AR_KR0, 0xffffc000000UL);
 165
 166         bp = sys_fw_init(args, arglen);
 167
 168         ssc(0, (long) kpath, 0, 0, SSC_LOAD_SYMBOLS);
 169
 170         debug_break();
 171         jmp_to_kernel((unsigned long) bp, e_entry);
 172
 173         cons_write("kernel returned!\n");
 174         ssc(-1, 0, 0, 0, SSC_EXIT);
 175 }