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/system.h> 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 23 extern int vsprintf(char *, const char *, va_list); 24 extern unsigned long switch_to_osf_pal(unsigned long nr, 25 struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa, 26 unsigned long *vptb); 27 struct hwrpb_struct *hwrpb = INIT_HWRPB; 28 static struct pcb_struct pcb_va[1]; 29 30 /* 31 * Find a physical address of a virtual object.. 32 * 33 * This is easy using the virtual page table address. 34 */ 35 36 static inline void * 37 find_pa(unsigned long *vptb, void *ptr) 38 { 39 unsigned long address = (unsigned long) ptr; 40 unsigned long result; 41 42 result = vptb[address >> 13]; 43 result >>= 32; 44 result <<= 13; 45 result |= address & 0x1fff; 46 return (void *) result; 47 } 48 49 /* 50 * This function moves into OSF/1 pal-code, and has a temporary 51 * PCB for that. The kernel proper should replace this PCB with 52 * the real one as soon as possible. 53 * 54 * The page table muckery in here depends on the fact that the boot 55 * code has the L1 page table identity-map itself in the second PTE 56 * in the L1 page table. Thus the L1-page is virtually addressable 57 * itself (through three levels) at virtual address 0x200802000. 58 */ 59 60 #define VPTB ((unsigned long *) 0x200000000) 61 #define L1 ((unsigned long *) 0x200802000) 62 63 void 64 pal_init(void) 65 { 66 unsigned long i, rev; 67 struct percpu_struct * percpu; 68 struct pcb_struct * pcb_pa; 69 70 /* Create the dummy PCB. */ 71 pcb_va->ksp = 0; 72 pcb_va->usp = 0; 73 pcb_va->ptbr = L1[1] >> 32; 74 pcb_va->asn = 0; 75 pcb_va->pcc = 0; 76 pcb_va->unique = 0; 77 pcb_va->flags = 1; 78 pcb_va->res1 = 0; 79 pcb_va->res2 = 0; 80 pcb_pa = find_pa(VPTB, pcb_va); 81 82 /* 83 * a0 = 2 (OSF) 84 * a1 = return address, but we give the asm the vaddr of the PCB 85 * a2 = physical addr of PCB 86 * a3 = new virtual page table pointer 87 * a4 = KSP (but the asm sets it) 88 */ 89 srm_printk("Switching to OSF PAL-code .. "); 90 91 i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB); 92 if (i) { 93 srm_printk("failed, code %ld\n", i); 94 __halt(); 95 } 96 97 percpu = (struct percpu_struct *) 98 (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB); 99 rev = percpu->pal_revision = percpu->palcode_avail[2]; 100 101 srm_printk("Ok (rev %lx)\n", rev); 102 103 tbia(); /* do it directly in case we are SMP */ 104 } 105 106 static inline long openboot(void) 107 { 108 char bootdev[256]; 109 long result; 110 111 result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255); 112 if (result < 0) 113 return result; 114 return callback_open(bootdev, result & 255); 115 } 116 117 static inline long close(long dev) 118 { 119 return callback_close(dev); 120 } 121 122 static inline long load(long dev, unsigned long addr, unsigned long count) 123 { 124 char bootfile[256]; 125 extern char _end; 126 long result, boot_size = &_end - (char *) BOOT_ADDR; 127 128 result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255); 129 if (result < 0) 130 return result; 131 result &= 255; 132 bootfile[result] = '\0'; 133 if (result) 134 srm_printk("Boot file specification (%s) not implemented\n", 135 bootfile); 136 return callback_read(dev, count, (void *)addr, boot_size/512 + 1); 137 } 138 139 /* 140 * Start the kernel. 141 */ 142 static void runkernel(void) 143 { 144 __asm__ __volatile__( 145 "bis %1,%1,$30\n\t" 146 "bis %0,%0,$26\n\t" 147 "ret ($26)" 148 : /* no outputs: it doesn't even return */ 149 : "r" (START_ADDR), 150 "r" (PAGE_SIZE + INIT_STACK)); 151 } 152 153 void start_kernel(void) 154 { 155 long i; 156 long dev; 157 int nbytes; 158 char envval[256]; 159 160 srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n"); 161 if (INIT_HWRPB->pagesize != 8192) { 162 srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10); 163 return; 164 } 165 pal_init(); 166 dev = openboot(); 167 if (dev < 0) { 168 srm_printk("Unable to open boot device: %016lx\n", dev); 169 return; 170 } 171 dev &= 0xffffffff; 172 srm_printk("Loading vmlinux ..."); 173 i = load(dev, START_ADDR, KERNEL_SIZE); 174 close(dev); 175 if (i != KERNEL_SIZE) { 176 srm_printk("Failed (%lx)\n", i); 177 return; 178 } 179 180 nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval)); 181 if (nbytes < 0) { 182 nbytes = 0; 183 } 184 envval[nbytes] = '\0'; 185 strcpy((char*)ZERO_PGE, envval); 186 187 srm_printk(" Ok\nNow booting the kernel\n"); 188 runkernel(); 189 for (i = 0 ; i < 0x100000000 ; i++) 190 /* nothing */; 191 __halt(); 192 } 193