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); 26 struct hwrpb_struct *hwrpb = INIT_HWRPB; 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 } 192