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1da177e4 LT |
1 | /* |
2 | * arch/alpha/boot/bootp.c | |
3 | * | |
4 | * Copyright (C) 1997 Jay Estabrook | |
5 | * | |
6 | * This file is used for creating a bootp file for the Linux/AXP kernel | |
7 | * | |
8 | * based significantly on the arch/alpha/boot/main.c of Linus Torvalds | |
9 | */ | |
10 | #include <linux/kernel.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
1da177e4 | 12 | #include <linux/string.h> |
273b281f | 13 | #include <generated/utsrelease.h> |
1da177e4 LT |
14 | #include <linux/mm.h> |
15 | ||
1da177e4 LT |
16 | #include <asm/console.h> |
17 | #include <asm/hwrpb.h> | |
18 | #include <asm/pgtable.h> | |
19 | #include <asm/io.h> | |
20 | ||
21 | #include <stdarg.h> | |
22 | ||
23 | #include "ksize.h" | |
24 | ||
25 | extern unsigned long switch_to_osf_pal(unsigned long nr, | |
26 | struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa, | |
27 | unsigned long *vptb); | |
28 | ||
29 | extern void move_stack(unsigned long new_stack); | |
30 | ||
31 | struct hwrpb_struct *hwrpb = INIT_HWRPB; | |
32 | static struct pcb_struct pcb_va[1]; | |
33 | ||
34 | /* | |
35 | * Find a physical address of a virtual object.. | |
36 | * | |
37 | * This is easy using the virtual page table address. | |
38 | */ | |
39 | ||
40 | static inline void * | |
41 | find_pa(unsigned long *vptb, void *ptr) | |
42 | { | |
43 | unsigned long address = (unsigned long) ptr; | |
44 | unsigned long result; | |
45 | ||
46 | result = vptb[address >> 13]; | |
47 | result >>= 32; | |
48 | result <<= 13; | |
49 | result |= address & 0x1fff; | |
50 | return (void *) result; | |
51 | } | |
52 | ||
53 | /* | |
54 | * This function moves into OSF/1 pal-code, and has a temporary | |
55 | * PCB for that. The kernel proper should replace this PCB with | |
56 | * the real one as soon as possible. | |
57 | * | |
58 | * The page table muckery in here depends on the fact that the boot | |
59 | * code has the L1 page table identity-map itself in the second PTE | |
60 | * in the L1 page table. Thus the L1-page is virtually addressable | |
61 | * itself (through three levels) at virtual address 0x200802000. | |
62 | */ | |
63 | ||
64 | #define VPTB ((unsigned long *) 0x200000000) | |
65 | #define L1 ((unsigned long *) 0x200802000) | |
66 | ||
67 | void | |
68 | pal_init(void) | |
69 | { | |
70 | unsigned long i, rev; | |
71 | struct percpu_struct * percpu; | |
72 | struct pcb_struct * pcb_pa; | |
73 | ||
74 | /* Create the dummy PCB. */ | |
75 | pcb_va->ksp = 0; | |
76 | pcb_va->usp = 0; | |
77 | pcb_va->ptbr = L1[1] >> 32; | |
78 | pcb_va->asn = 0; | |
79 | pcb_va->pcc = 0; | |
80 | pcb_va->unique = 0; | |
81 | pcb_va->flags = 1; | |
82 | pcb_va->res1 = 0; | |
83 | pcb_va->res2 = 0; | |
84 | pcb_pa = find_pa(VPTB, pcb_va); | |
85 | ||
86 | /* | |
87 | * a0 = 2 (OSF) | |
88 | * a1 = return address, but we give the asm the vaddr of the PCB | |
89 | * a2 = physical addr of PCB | |
90 | * a3 = new virtual page table pointer | |
91 | * a4 = KSP (but the asm sets it) | |
92 | */ | |
93 | srm_printk("Switching to OSF PAL-code .. "); | |
94 | ||
95 | i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB); | |
96 | if (i) { | |
97 | srm_printk("failed, code %ld\n", i); | |
98 | __halt(); | |
99 | } | |
100 | ||
101 | percpu = (struct percpu_struct *) | |
102 | (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB); | |
103 | rev = percpu->pal_revision = percpu->palcode_avail[2]; | |
104 | ||
105 | srm_printk("Ok (rev %lx)\n", rev); | |
106 | ||
107 | tbia(); /* do it directly in case we are SMP */ | |
108 | } | |
109 | ||
110 | static inline void | |
111 | load(unsigned long dst, unsigned long src, unsigned long count) | |
112 | { | |
113 | memcpy((void *)dst, (void *)src, count); | |
114 | } | |
115 | ||
116 | /* | |
117 | * Start the kernel. | |
118 | */ | |
119 | static inline void | |
120 | runkernel(void) | |
121 | { | |
122 | __asm__ __volatile__( | |
123 | "bis %0,%0,$27\n\t" | |
124 | "jmp ($27)" | |
125 | : /* no outputs: it doesn't even return */ | |
126 | : "r" (START_ADDR)); | |
127 | } | |
128 | ||
129 | extern char _end; | |
130 | #define KERNEL_ORIGIN \ | |
131 | ((((unsigned long)&_end) + 511) & ~511) | |
132 | ||
133 | void | |
134 | start_kernel(void) | |
135 | { | |
136 | /* | |
137 | * Note that this crufty stuff with static and envval | |
138 | * and envbuf is because: | |
139 | * | |
140 | * 1. Frequently, the stack is short, and we don't want to overrun; | |
141 | * 2. Frequently the stack is where we are going to copy the kernel to; | |
142 | * 3. A certain SRM console required the GET_ENV output to stack. | |
143 | * ??? A comment in the aboot sources indicates that the GET_ENV | |
144 | * destination must be quadword aligned. Might this explain the | |
145 | * behaviour, rather than requiring output to the stack, which | |
146 | * seems rather far-fetched. | |
147 | */ | |
148 | static long nbytes; | |
149 | static char envval[256] __attribute__((aligned(8))); | |
150 | static unsigned long initrd_start; | |
151 | ||
152 | srm_printk("Linux/AXP bootp loader for Linux " UTS_RELEASE "\n"); | |
153 | if (INIT_HWRPB->pagesize != 8192) { | |
154 | srm_printk("Expected 8kB pages, got %ldkB\n", | |
155 | INIT_HWRPB->pagesize >> 10); | |
156 | return; | |
157 | } | |
158 | if (INIT_HWRPB->vptb != (unsigned long) VPTB) { | |
159 | srm_printk("Expected vptb at %p, got %p\n", | |
160 | VPTB, (void *)INIT_HWRPB->vptb); | |
161 | return; | |
162 | } | |
163 | pal_init(); | |
164 | ||
165 | /* The initrd must be page-aligned. See below for the | |
166 | cause of the magic number 5. */ | |
167 | initrd_start = ((START_ADDR + 5*KERNEL_SIZE + PAGE_SIZE) | | |
168 | (PAGE_SIZE-1)) + 1; | |
169 | #ifdef INITRD_IMAGE_SIZE | |
170 | srm_printk("Initrd positioned at %#lx\n", initrd_start); | |
171 | #endif | |
172 | ||
173 | /* | |
174 | * Move the stack to a safe place to ensure it won't be | |
175 | * overwritten by kernel image. | |
176 | */ | |
177 | move_stack(initrd_start - PAGE_SIZE); | |
178 | ||
179 | nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval)); | |
180 | if (nbytes < 0 || nbytes >= sizeof(envval)) { | |
181 | nbytes = 0; | |
182 | } | |
183 | envval[nbytes] = '\0'; | |
184 | srm_printk("Loading the kernel...'%s'\n", envval); | |
185 | ||
186 | /* NOTE: *no* callbacks or printouts from here on out!!! */ | |
187 | ||
188 | /* This is a hack, as some consoles seem to get virtual 20000000 (ie | |
189 | * where the SRM console puts the kernel bootp image) memory | |
190 | * overlapping physical memory where the kernel wants to be put, | |
191 | * which causes real problems when attempting to copy the former to | |
192 | * the latter... :-( | |
193 | * | |
194 | * So, we first move the kernel virtual-to-physical way above where | |
195 | * we physically want the kernel to end up, then copy it from there | |
196 | * to its final resting place... ;-} | |
197 | * | |
198 | * Sigh... */ | |
199 | ||
200 | #ifdef INITRD_IMAGE_SIZE | |
201 | load(initrd_start, KERNEL_ORIGIN+KERNEL_SIZE, INITRD_IMAGE_SIZE); | |
202 | #endif | |
203 | load(START_ADDR+(4*KERNEL_SIZE), KERNEL_ORIGIN, KERNEL_SIZE); | |
204 | load(START_ADDR, START_ADDR+(4*KERNEL_SIZE), KERNEL_SIZE); | |
205 | ||
206 | memset((char*)ZERO_PGE, 0, PAGE_SIZE); | |
207 | strcpy((char*)ZERO_PGE, envval); | |
208 | #ifdef INITRD_IMAGE_SIZE | |
209 | ((long *)(ZERO_PGE+256))[0] = initrd_start; | |
210 | ((long *)(ZERO_PGE+256))[1] = INITRD_IMAGE_SIZE; | |
211 | #endif | |
212 | ||
213 | runkernel(); | |
214 | } |