Linux Kernel  3.7.1
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main.c
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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/slab.h>
10 #include <linux/string.h>
11 #include <generated/utsrelease.h>
12 #include <linux/mm.h>
13 
14 #include <asm/console.h>
15 #include <asm/hwrpb.h>
16 #include <asm/pgtable.h>
17 
18 #include <stdarg.h>
19 
20 #include "ksize.h"
21 
22 extern int vsprintf(char *, const char *, va_list);
23 extern unsigned long switch_to_osf_pal(unsigned long nr,
24  struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
25  unsigned long *vptb);
27 static struct pcb_struct pcb_va[1];
28 
29 /*
30  * Find a physical address of a virtual object..
31  *
32  * This is easy using the virtual page table address.
33  */
34 
35 static inline void *
36 find_pa(unsigned long *vptb, void *ptr)
37 {
38  unsigned long address = (unsigned long) ptr;
39  unsigned long result;
40 
41  result = vptb[address >> 13];
42  result >>= 32;
43  result <<= 13;
44  result |= address & 0x1fff;
45  return (void *) result;
46 }
47 
48 /*
49  * This function moves into OSF/1 pal-code, and has a temporary
50  * PCB for that. The kernel proper should replace this PCB with
51  * the real one as soon as possible.
52  *
53  * The page table muckery in here depends on the fact that the boot
54  * code has the L1 page table identity-map itself in the second PTE
55  * in the L1 page table. Thus the L1-page is virtually addressable
56  * itself (through three levels) at virtual address 0x200802000.
57  */
58 
59 #define VPTB ((unsigned long *) 0x200000000)
60 #define L1 ((unsigned long *) 0x200802000)
61 
62 void
63 pal_init(void)
64 {
65  unsigned long i, rev;
66  struct percpu_struct * percpu;
67  struct pcb_struct * pcb_pa;
68 
69  /* Create the dummy PCB. */
70  pcb_va->ksp = 0;
71  pcb_va->usp = 0;
72  pcb_va->ptbr = L1[1] >> 32;
73  pcb_va->asn = 0;
74  pcb_va->pcc = 0;
75  pcb_va->unique = 0;
76  pcb_va->flags = 1;
77  pcb_va->res1 = 0;
78  pcb_va->res2 = 0;
79  pcb_pa = find_pa(VPTB, pcb_va);
80 
81  /*
82  * a0 = 2 (OSF)
83  * a1 = return address, but we give the asm the vaddr of the PCB
84  * a2 = physical addr of PCB
85  * a3 = new virtual page table pointer
86  * a4 = KSP (but the asm sets it)
87  */
88  srm_printk("Switching to OSF PAL-code .. ");
89 
90  i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
91  if (i) {
92  srm_printk("failed, code %ld\n", i);
93  __halt();
94  }
95 
96  percpu = (struct percpu_struct *)
97  (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
98  rev = percpu->pal_revision = percpu->palcode_avail[2];
99 
100  srm_printk("Ok (rev %lx)\n", rev);
101 
102  tbia(); /* do it directly in case we are SMP */
103 }
104 
105 static inline long openboot(void)
106 {
107  char bootdev[256];
108  long result;
109 
110  result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);
111  if (result < 0)
112  return result;
113  return callback_open(bootdev, result & 255);
114 }
115 
116 static inline long close(long dev)
117 {
118  return callback_close(dev);
119 }
120 
121 static inline long load(long dev, unsigned long addr, unsigned long count)
122 {
123  char bootfile[256];
124  extern char _end;
125  long result, boot_size = &_end - (char *) BOOT_ADDR;
126 
127  result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);
128  if (result < 0)
129  return result;
130  result &= 255;
131  bootfile[result] = '\0';
132  if (result)
133  srm_printk("Boot file specification (%s) not implemented\n",
134  bootfile);
135  return callback_read(dev, count, (void *)addr, boot_size/512 + 1);
136 }
137 
138 /*
139  * Start the kernel.
140  */
141 static void runkernel(void)
142 {
143  __asm__ __volatile__(
144  "bis %1,%1,$30\n\t"
145  "bis %0,%0,$26\n\t"
146  "ret ($26)"
147  : /* no outputs: it doesn't even return */
148  : "r" (START_ADDR),
149  "r" (PAGE_SIZE + INIT_STACK));
150 }
151 
152 void start_kernel(void)
153 {
154  long i;
155  long dev;
156  int nbytes;
157  char envval[256];
158 
159  srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
160  if (INIT_HWRPB->pagesize != 8192) {
161  srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);
162  return;
163  }
164  pal_init();
165  dev = openboot();
166  if (dev < 0) {
167  srm_printk("Unable to open boot device: %016lx\n", dev);
168  return;
169  }
170  dev &= 0xffffffff;
171  srm_printk("Loading vmlinux ...");
172  i = load(dev, START_ADDR, KERNEL_SIZE);
173  close(dev);
174  if (i != KERNEL_SIZE) {
175  srm_printk("Failed (%lx)\n", i);
176  return;
177  }
178 
179  nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
180  if (nbytes < 0) {
181  nbytes = 0;
182  }
183  envval[nbytes] = '\0';
184  strcpy((char*)ZERO_PGE, envval);
185 
186  srm_printk(" Ok\nNow booting the kernel\n");
187  runkernel();
188  for (i = 0 ; i < 0x100000000 ; i++)
189  /* nothing */;
190  __halt();
191 }