arch/alpha/boot/main.c

/* */
This source file includes following definitions.
printk
find_pa
pal_init
openboot
close
load
runkernel
start_kernel
   1 /*
   2  * arch/alpha/boot/main.c
   3  *
   4  * Copyright (C) 1994, 1995 Linus Torvalds
   5  *
   6  * This file is the bootloader for the Linux/AXP kernel
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/string.h>
  10 #include <linux/version.h>
  11 #include <linux/mm.h>
  12 
  13 #include <asm/system.h>
  14 #include <asm/console.h>
  15 #include <asm/hwrpb.h>
  16 #include <asm/pgtable.h>
  17 
  18 #include <stdarg.h>
  19 
  20 extern int vsprintf(char *, const char *, va_list);
  21 extern unsigned long switch_to_osf_pal(unsigned long nr,
  22         struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
  23         unsigned long vptb, unsigned long *kstk);
  24 
  25 int printk(const char * fmt, ...)
     /*  */
  26 {
  27         va_list args;
  28         int i, j, written, remaining, num_nl;
  29         static char buf[1024];
  30         char * str;
  31 
  32         va_start(args, fmt);
  33         i = vsprintf(buf, fmt, args);
  34         va_end(args);
  35 
  36         /* expand \n into \r\n: */
  37 
  38         num_nl = 0;
  39         for (j = 0; j < i; ++j) {
  40             if (buf[j] == '\n')
  41                 ++num_nl;
  42         }
  43         remaining = i + num_nl;
  44         for (j = i - 1; j >= 0; --j) {
  45             buf[j + num_nl] = buf[j];
  46             if (buf[j] == '\n') {
  47                 --num_nl;
  48                 buf[j + num_nl] = '\r';
  49             }
  50         }
  51 
  52         str = buf;
  53         do {
  54             written = puts(str, remaining);
  55             remaining -= written;
  56             str += written;
  57         } while (remaining > 0);
  58         return i;
  59 }
  60 
  61 #define hwrpb (*INIT_HWRPB)
  62 
  63 /*
  64  * Find a physical address of a virtual object..
  65  *
  66  * This is easy using the virtual page table address.
  67  */
  68 struct pcb_struct * find_pa(unsigned long *vptb, struct pcb_struct * pcb)
     /*  */
  69 {
  70         unsigned long address = (unsigned long) pcb;
  71         unsigned long result;
  72 
  73         result = vptb[address >> 13];
  74         result >>= 32;
  75         result <<= 13;
  76         result |= address & 0x1fff;
  77         return (struct pcb_struct *) result;
  78 }       
  79 
  80 /*
  81  * This function moves into OSF/1 pal-code, and has a temporary
  82  * PCB for that. The kernel proper should replace this PCB with
  83  * the real one as soon as possible.
  84  *
  85  * The page table muckery in here depends on the fact that the boot
  86  * code has the L1 page table identity-map itself in the second PTE
  87  * in the L1 page table. Thus the L1-page is virtually addressable
  88  * itself (through three levels) at virtual address 0x200802000.
  89  *
  90  * As we don't want it there anyway, we also move the L1 self-map
  91  * up as high as we can, so that the last entry in the L1 page table
  92  * maps the page tables.
  93  *
  94  * As a result, the OSF/1 pal-code will instead use a virtual page table
  95  * map located at 0xffffffe00000000.
  96  */
  97 #define pcb_va ((struct pcb_struct *) 0x20000000)
  98 #define old_vptb (0x0000000200000000UL)
  99 #define new_vptb (0xfffffffe00000000UL)
 100 void pal_init(void)
     /*  */
 101 {
 102         unsigned long i, rev, sum;
 103         unsigned long *L1, *l;
 104         struct percpu_struct * percpu;
 105         struct pcb_struct * pcb_pa;
 106 
 107         /* Find the level 1 page table and duplicate it in high memory */
 108         L1 = (unsigned long *) 0x200802000UL; /* (1<<33 | 1<<23 | 1<<13) */
 109         L1[1023] = L1[1];
 110 
 111         percpu = (struct percpu_struct *) (hwrpb.processor_offset + (unsigned long) &hwrpb),
 112                 
 113         pcb_va->ksp = 0;
 114         pcb_va->usp = 0;
 115         pcb_va->ptbr = L1[1] >> 32;
 116         pcb_va->asn = 0;
 117         pcb_va->pcc = 0;
 118         pcb_va->unique = 0;
 119         pcb_va->flags = 1;
 120         pcb_pa = find_pa((unsigned long *) old_vptb, pcb_va);
 121         printk("Switching to OSF PAL-code .. ");
 122         /*
 123          * a0 = 2 (OSF)
 124          * a1 = return address, but we give the asm the virtual addr of the PCB
 125          * a2 = physical addr of PCB
 126          * a3 = new virtual page table pointer
 127          * a4 = KSP (but we give it 0, asm sets it)
 128          */
 129         i = switch_to_osf_pal(
 130                 2,
 131                 pcb_va,
 132                 pcb_pa,
 133                 new_vptb,
 134                 0);
 135         if (i) {
 136                 printk("failed, code %ld\n", i);
 137                 halt();
 138         }
 139         rev = percpu->pal_revision = percpu->palcode_avail[2];
 140 
 141         hwrpb.vptb = new_vptb;
 142 
 143         /* update checksum: */
 144         sum = 0;
 145         for (l = (unsigned long *) &hwrpb; l < (unsigned long *) &hwrpb.chksum; ++l)
 146                 sum += *l;
 147         hwrpb.chksum = sum;
 148 
 149         printk("Ok (rev %lx)\n", rev);
 150         /* remove the old virtual page-table mapping */
 151         L1[1] = 0;
 152         flush_tlb_all();
 153 }
 154 
 155 extern int _end;
 156 
 157 static inline long openboot(void)
     /*  */
 158 {
 159         char bootdev[256];
 160         long result;
 161 
 162         result = dispatch(CCB_GET_ENV, ENV_BOOTED_DEV, bootdev, 255);
 163         if (result < 0)
 164                 return result;
 165         return dispatch(CCB_OPEN, bootdev, result & 255);
 166 }
 167 
 168 static inline long close(long dev)
     /*  */
 169 {
 170         return dispatch(CCB_CLOSE, dev);
 171 }
 172 
 173 static inline long load(long dev, unsigned long addr, unsigned long count)
     /*  */
 174 {
 175         char bootfile[256];
 176         long result;
 177 
 178         result = dispatch(CCB_GET_ENV, ENV_BOOTED_FILE, bootfile, 255);
 179         if (result < 0)
 180                 return result;
 181         result &= 255;
 182         bootfile[result] = '\0';
 183         if (result)
 184                 printk("Boot file specification (%s) not implemented\n", bootfile);
 185         return dispatch(CCB_READ, dev, count, addr, BOOT_SIZE/512 + 1);
 186 }
 187 
 188 /*
 189  * Start the kernel.
 190  */
 191 static void runkernel(void)
     /*  */
 192 {
 193         __asm__ __volatile__(
 194                 "bis %1,%1,$30\n\t"
 195                 "bis %0,%0,$26\n\t"
 196                 "ret ($26)"
 197                 : /* no outputs: it doesn't even return */
 198                 : "r" (START_ADDR),
 199                   "r" (PAGE_SIZE + INIT_STACK));
 200 }
 201 
 202 void start_kernel(void)
     /*  */
 203 {
 204         long i;
 205         long dev;
 206         int nbytes;
 207         char envval[256];
 208 
 209         printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
 210         if (hwrpb.pagesize != 8192) {
 211                 printk("Expected 8kB pages, got %ldkB\n", hwrpb.pagesize >> 10);
 212                 return;
 213         }
 214         pal_init();
 215         dev = openboot();
 216         if (dev < 0) {
 217                 printk("Unable to open boot device: %016lx\n", dev);
 218                 return;
 219         }
 220         dev &= 0xffffffff;
 221         printk("Loading vmlinux ...");
 222         i = load(dev, START_ADDR, START_SIZE);
 223         close(dev);
 224         if (i != START_SIZE) {
 225                 printk("Failed (%lx)\n", i);
 226                 return;
 227         }
 228 
 229         nbytes = dispatch(CCB_GET_ENV, ENV_BOOTED_OSFLAGS,
 230                           envval, sizeof(envval));
 231         if (nbytes > 0) {
 232                 envval[nbytes] = '\0';
 233                 strcpy((char*)ZERO_PAGE, envval);
 234         }
 235 
 236         printk(" Ok\nNow booting the kernel\n");
 237         runkernel();
 238         for (i = 0 ; i < 0x100000000 ; i++)
 239                 /* nothing */;
 240         halt();
 241 }
/* */
root/arch/alpha/boot/main.c

DEFINITIONS
