Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/alpha/boot/main.c
4 *
5 * Copyright (C) 1994, 1995 Linus Torvalds
6 *
7 * This file is the bootloader for the Linux/AXP kernel
8 */
9#include <linux/kernel.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12#include <generated/utsrelease.h>
13#include <linux/mm.h>
14
15#include <asm/console.h>
16#include <asm/hwrpb.h>
17#include <asm/pgtable.h>
18
19#include <stdarg.h>
20
21#include "ksize.h"
22
23extern unsigned long switch_to_osf_pal(unsigned long nr,
24 struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
25 unsigned long *vptb);
26struct hwrpb_struct *hwrpb = INIT_HWRPB;
27static 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
35static inline void *
36find_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
62void
63pal_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
105static 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
116static inline long close(long dev)
117{
118 return callback_close(dev);
119}
120
121static 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 */
141static 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
152void 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}