1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch/alpha/boot/bootpz.c 4 * 5 * Copyright (C) 1997 Jay Estabrook 6 * 7 * This file is used for creating a compressed BOOTP file for the 8 * Linux/AXP kernel 9 * 10 * based significantly on the arch/alpha/boot/main.c of Linus Torvalds 11 * and the decompression code from MILO. 12 */ 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/string.h> 16 #include <generated/utsrelease.h> 17 #include <linux/mm.h> 18 19 #include <asm/console.h> 20 #include <asm/hwrpb.h> 21 #include <asm/pgtable.h> 22 #include <asm/io.h> 23 24 #include <stdarg.h> 25 26 #include "kzsize.h" 27 28 /* FIXME FIXME FIXME */ 29 #define MALLOC_AREA_SIZE 0x200000 /* 2MB for now */ 30 /* FIXME FIXME FIXME */ 31 32 33 /* 34 WARNING NOTE 35 36 It is very possible that turning on additional messages may cause 37 kernel image corruption due to stack usage to do the printing. 38 39 */ 40 41 #undef DEBUG_CHECK_RANGE 42 #undef DEBUG_ADDRESSES 43 #undef DEBUG_LAST_STEPS 44 45 extern unsigned long switch_to_osf_pal(unsigned long nr, 46 struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa, 47 unsigned long *vptb); 48 49 extern int decompress_kernel(void* destination, void *source, 50 size_t ksize, size_t kzsize); 51 52 extern void move_stack(unsigned long new_stack); 53 54 struct hwrpb_struct *hwrpb = INIT_HWRPB; 55 static struct pcb_struct pcb_va[1]; 56 57 /* 58 * Find a physical address of a virtual object.. 59 * 60 * This is easy using the virtual page table address. 61 */ 62 #define VPTB ((unsigned long *) 0x200000000) 63 64 static inline unsigned long 65 find_pa(unsigned long address) 66 { 67 unsigned long result; 68 69 result = VPTB[address >> 13]; 70 result >>= 32; 71 result <<= 13; 72 result |= address & 0x1fff; 73 return result; 74 } 75 76 int 77 check_range(unsigned long vstart, unsigned long vend, 78 unsigned long kstart, unsigned long kend) 79 { 80 unsigned long vaddr, kaddr; 81 82 #ifdef DEBUG_CHECK_RANGE 83 srm_printk("check_range: V[0x%lx:0x%lx] K[0x%lx:0x%lx]\n", 84 vstart, vend, kstart, kend); 85 #endif 86 /* do some range checking for detecting an overlap... */ 87 for (vaddr = vstart; vaddr <= vend; vaddr += PAGE_SIZE) 88 { 89 kaddr = (find_pa(vaddr) | PAGE_OFFSET); 90 if (kaddr >= kstart && kaddr <= kend) 91 { 92 #ifdef DEBUG_CHECK_RANGE 93 srm_printk("OVERLAP: vaddr 0x%lx kaddr 0x%lx" 94 " [0x%lx:0x%lx]\n", 95 vaddr, kaddr, kstart, kend); 96 #endif 97 return 1; 98 } 99 } 100 return 0; 101 } 102 103 /* 104 * This function moves into OSF/1 pal-code, and has a temporary 105 * PCB for that. The kernel proper should replace this PCB with 106 * the real one as soon as possible. 107 * 108 * The page table muckery in here depends on the fact that the boot 109 * code has the L1 page table identity-map itself in the second PTE 110 * in the L1 page table. Thus the L1-page is virtually addressable 111 * itself (through three levels) at virtual address 0x200802000. 112 */ 113 114 #define L1 ((unsigned long *) 0x200802000) 115 116 void 117 pal_init(void) 118 { 119 unsigned long i, rev; 120 struct percpu_struct * percpu; 121 struct pcb_struct * pcb_pa; 122 123 /* Create the dummy PCB. */ 124 pcb_va->ksp = 0; 125 pcb_va->usp = 0; 126 pcb_va->ptbr = L1[1] >> 32; 127 pcb_va->asn = 0; 128 pcb_va->pcc = 0; 129 pcb_va->unique = 0; 130 pcb_va->flags = 1; 131 pcb_va->res1 = 0; 132 pcb_va->res2 = 0; 133 pcb_pa = (struct pcb_struct *)find_pa((unsigned long)pcb_va); 134 135 /* 136 * a0 = 2 (OSF) 137 * a1 = return address, but we give the asm the vaddr of the PCB 138 * a2 = physical addr of PCB 139 * a3 = new virtual page table pointer 140 * a4 = KSP (but the asm sets it) 141 */ 142 srm_printk("Switching to OSF PAL-code... "); 143 144 i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB); 145 if (i) { 146 srm_printk("failed, code %ld\n", i); 147 __halt(); 148 } 149 150 percpu = (struct percpu_struct *) 151 (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB); 152 rev = percpu->pal_revision = percpu->palcode_avail[2]; 153 154 srm_printk("OK (rev %lx)\n", rev); 155 156 tbia(); /* do it directly in case we are SMP */ 157 } 158 159 /* 160 * Start the kernel. 161 */ 162 static inline void 163 runkernel(void) 164 { 165 __asm__ __volatile__( 166 "bis %0,%0,$27\n\t" 167 "jmp ($27)" 168 : /* no outputs: it doesn't even return */ 169 : "r" (START_ADDR)); 170 } 171 172 /* Must record the SP (it is virtual) on entry, so we can make sure 173 not to overwrite it during movement or decompression. */ 174 unsigned long SP_on_entry; 175 176 /* Calculate the kernel image address based on the end of the BOOTP 177 bootstrapper (ie this program). 178 */ 179 extern char _end; 180 #define KERNEL_ORIGIN \ 181 ((((unsigned long)&_end) + 511) & ~511) 182 183 /* Round address to next higher page boundary. */ 184 #define NEXT_PAGE(a) (((a) | (PAGE_SIZE - 1)) + 1) 185 186 #ifdef INITRD_IMAGE_SIZE 187 # define REAL_INITRD_SIZE INITRD_IMAGE_SIZE 188 #else 189 # define REAL_INITRD_SIZE 0 190 #endif 191 192 /* Defines from include/asm-alpha/system.h 193 194 BOOT_ADDR Virtual address at which the consoles loads 195 the BOOTP image. 196 197 KERNEL_START KSEG address at which the kernel is built to run, 198 which includes some initial data pages before the 199 code. 200 201 START_ADDR KSEG address of the entry point of kernel code. 202 203 ZERO_PGE KSEG address of page full of zeroes, but 204 upon entry to kerne cvan be expected 205 to hold the parameter list and possible 206 INTRD information. 207 208 These are used in the local defines below. 209 */ 210 211 212 /* Virtual addresses for the BOOTP image. Note that this includes the 213 bootstrapper code as well as the compressed kernel image, and 214 possibly the INITRD image. 215 216 Oh, and do NOT forget the STACK, which appears to be placed virtually 217 beyond the end of the loaded image. 218 */ 219 #define V_BOOT_IMAGE_START BOOT_ADDR 220 #define V_BOOT_IMAGE_END SP_on_entry 221 222 /* Virtual addresses for just the bootstrapper part of the BOOTP image. */ 223 #define V_BOOTSTRAPPER_START BOOT_ADDR 224 #define V_BOOTSTRAPPER_END KERNEL_ORIGIN 225 226 /* Virtual addresses for just the data part of the BOOTP 227 image. This may also include the INITRD image, but always 228 includes the STACK. 229 */ 230 #define V_DATA_START KERNEL_ORIGIN 231 #define V_INITRD_START (KERNEL_ORIGIN + KERNEL_Z_SIZE) 232 #define V_INTRD_END (V_INITRD_START + REAL_INITRD_SIZE) 233 #define V_DATA_END V_BOOT_IMAGE_END 234 235 /* KSEG addresses for the uncompressed kernel. 236 237 Note that the end address includes workspace for the decompression. 238 Note also that the DATA_START address is ZERO_PGE, to which we write 239 just before jumping to the kernel image at START_ADDR. 240 */ 241 #define K_KERNEL_DATA_START ZERO_PGE 242 #define K_KERNEL_IMAGE_START START_ADDR 243 #define K_KERNEL_IMAGE_END (START_ADDR + KERNEL_SIZE) 244 245 /* Define to where we may have to decompress the kernel image, before 246 we move it to the final position, in case of overlap. This will be 247 above the final position of the kernel. 248 249 Regardless of overlap, we move the INITRD image to the end of this 250 copy area, because there needs to be a buffer area after the kernel 251 for "bootmem" anyway. 252 */ 253 #define K_COPY_IMAGE_START NEXT_PAGE(K_KERNEL_IMAGE_END) 254 /* Reserve one page below INITRD for the new stack. */ 255 #define K_INITRD_START \ 256 NEXT_PAGE(K_COPY_IMAGE_START + KERNEL_SIZE + PAGE_SIZE) 257 #define K_COPY_IMAGE_END \ 258 (K_INITRD_START + REAL_INITRD_SIZE + MALLOC_AREA_SIZE) 259 #define K_COPY_IMAGE_SIZE \ 260 NEXT_PAGE(K_COPY_IMAGE_END - K_COPY_IMAGE_START) 261 262 void 263 start_kernel(void) 264 { 265 int must_move = 0; 266 267 /* Initialize these for the decompression-in-place situation, 268 which is the smallest amount of work and most likely to 269 occur when using the normal START_ADDR of the kernel 270 (currently set to 16MB, to clear all console code. 271 */ 272 unsigned long uncompressed_image_start = K_KERNEL_IMAGE_START; 273 unsigned long uncompressed_image_end = K_KERNEL_IMAGE_END; 274 275 unsigned long initrd_image_start = K_INITRD_START; 276 277 /* 278 * Note that this crufty stuff with static and envval 279 * and envbuf is because: 280 * 281 * 1. Frequently, the stack is short, and we don't want to overrun; 282 * 2. Frequently the stack is where we are going to copy the kernel to; 283 * 3. A certain SRM console required the GET_ENV output to stack. 284 * ??? A comment in the aboot sources indicates that the GET_ENV 285 * destination must be quadword aligned. Might this explain the 286 * behaviour, rather than requiring output to the stack, which 287 * seems rather far-fetched. 288 */ 289 static long nbytes; 290 static char envval[256] __attribute__((aligned(8))); 291 register unsigned long asm_sp asm("30"); 292 293 SP_on_entry = asm_sp; 294 295 srm_printk("Linux/Alpha BOOTPZ Loader for Linux " UTS_RELEASE "\n"); 296 297 /* Validity check the HWRPB. */ 298 if (INIT_HWRPB->pagesize != 8192) { 299 srm_printk("Expected 8kB pages, got %ldkB\n", 300 INIT_HWRPB->pagesize >> 10); 301 return; 302 } 303 if (INIT_HWRPB->vptb != (unsigned long) VPTB) { 304 srm_printk("Expected vptb at %p, got %p\n", 305 VPTB, (void *)INIT_HWRPB->vptb); 306 return; 307 } 308 309 /* PALcode (re)initialization. */ 310 pal_init(); 311 312 /* Get the parameter list from the console environment variable. */ 313 nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval)); 314 if (nbytes < 0 || nbytes >= sizeof(envval)) { 315 nbytes = 0; 316 } 317 envval[nbytes] = '\0'; 318 319 #ifdef DEBUG_ADDRESSES 320 srm_printk("START_ADDR 0x%lx\n", START_ADDR); 321 srm_printk("KERNEL_ORIGIN 0x%lx\n", KERNEL_ORIGIN); 322 srm_printk("KERNEL_SIZE 0x%x\n", KERNEL_SIZE); 323 srm_printk("KERNEL_Z_SIZE 0x%x\n", KERNEL_Z_SIZE); 324 #endif 325 326 /* Since all the SRM consoles load the BOOTP image at virtual 327 * 0x20000000, we have to ensure that the physical memory 328 * pages occupied by that image do NOT overlap the physical 329 * address range where the kernel wants to be run. This 330 * causes real problems when attempting to cdecompress the 331 * former into the latter... :-( 332 * 333 * So, we may have to decompress/move the kernel/INITRD image 334 * virtual-to-physical someplace else first before moving 335 * kernel /INITRD to their final resting places... ;-} 336 * 337 * Sigh... 338 */ 339 340 /* First, check to see if the range of addresses occupied by 341 the bootstrapper part of the BOOTP image include any of the 342 physical pages into which the kernel will be placed for 343 execution. 344 345 We only need check on the final kernel image range, since we 346 will put the INITRD someplace that we can be sure is not 347 in conflict. 348 */ 349 if (check_range(V_BOOTSTRAPPER_START, V_BOOTSTRAPPER_END, 350 K_KERNEL_DATA_START, K_KERNEL_IMAGE_END)) 351 { 352 srm_printk("FATAL ERROR: overlap of bootstrapper code\n"); 353 __halt(); 354 } 355 356 /* Next, check to see if the range of addresses occupied by 357 the compressed kernel/INITRD/stack portion of the BOOTP 358 image include any of the physical pages into which the 359 decompressed kernel or the INITRD will be placed for 360 execution. 361 */ 362 if (check_range(V_DATA_START, V_DATA_END, 363 K_KERNEL_IMAGE_START, K_COPY_IMAGE_END)) 364 { 365 #ifdef DEBUG_ADDRESSES 366 srm_printk("OVERLAP: cannot decompress in place\n"); 367 #endif 368 uncompressed_image_start = K_COPY_IMAGE_START; 369 uncompressed_image_end = K_COPY_IMAGE_END; 370 must_move = 1; 371 372 /* Finally, check to see if the range of addresses 373 occupied by the compressed kernel/INITRD part of 374 the BOOTP image include any of the physical pages 375 into which that part is to be copied for 376 decompression. 377 */ 378 while (check_range(V_DATA_START, V_DATA_END, 379 uncompressed_image_start, 380 uncompressed_image_end)) 381 { 382 #if 0 383 uncompressed_image_start += K_COPY_IMAGE_SIZE; 384 uncompressed_image_end += K_COPY_IMAGE_SIZE; 385 initrd_image_start += K_COPY_IMAGE_SIZE; 386 #else 387 /* Keep as close as possible to end of BOOTP image. */ 388 uncompressed_image_start += PAGE_SIZE; 389 uncompressed_image_end += PAGE_SIZE; 390 initrd_image_start += PAGE_SIZE; 391 #endif 392 } 393 } 394 395 srm_printk("Starting to load the kernel with args '%s'\n", envval); 396 397 #ifdef DEBUG_ADDRESSES 398 srm_printk("Decompressing the kernel...\n" 399 "...from 0x%lx to 0x%lx size 0x%x\n", 400 V_DATA_START, 401 uncompressed_image_start, 402 KERNEL_SIZE); 403 #endif 404 decompress_kernel((void *)uncompressed_image_start, 405 (void *)V_DATA_START, 406 KERNEL_SIZE, KERNEL_Z_SIZE); 407 408 /* 409 * Now, move things to their final positions, if/as required. 410 */ 411 412 #ifdef INITRD_IMAGE_SIZE 413 414 /* First, we always move the INITRD image, if present. */ 415 #ifdef DEBUG_ADDRESSES 416 srm_printk("Moving the INITRD image...\n" 417 " from 0x%lx to 0x%lx size 0x%x\n", 418 V_INITRD_START, 419 initrd_image_start, 420 INITRD_IMAGE_SIZE); 421 #endif 422 memcpy((void *)initrd_image_start, (void *)V_INITRD_START, 423 INITRD_IMAGE_SIZE); 424 425 #endif /* INITRD_IMAGE_SIZE */ 426 427 /* Next, we may have to move the uncompressed kernel to the 428 final destination. 429 */ 430 if (must_move) { 431 #ifdef DEBUG_ADDRESSES 432 srm_printk("Moving the uncompressed kernel...\n" 433 "...from 0x%lx to 0x%lx size 0x%x\n", 434 uncompressed_image_start, 435 K_KERNEL_IMAGE_START, 436 (unsigned)KERNEL_SIZE); 437 #endif 438 /* 439 * Move the stack to a safe place to ensure it won't be 440 * overwritten by kernel image. 441 */ 442 move_stack(initrd_image_start - PAGE_SIZE); 443 444 memcpy((void *)K_KERNEL_IMAGE_START, 445 (void *)uncompressed_image_start, KERNEL_SIZE); 446 } 447 448 /* Clear the zero page, then move the argument list in. */ 449 #ifdef DEBUG_LAST_STEPS 450 srm_printk("Preparing ZERO_PGE...\n"); 451 #endif 452 memset((char*)ZERO_PGE, 0, PAGE_SIZE); 453 strcpy((char*)ZERO_PGE, envval); 454 455 #ifdef INITRD_IMAGE_SIZE 456 457 #ifdef DEBUG_LAST_STEPS 458 srm_printk("Preparing INITRD info...\n"); 459 #endif 460 /* Finally, set the INITRD paramenters for the kernel. */ 461 ((long *)(ZERO_PGE+256))[0] = initrd_image_start; 462 ((long *)(ZERO_PGE+256))[1] = INITRD_IMAGE_SIZE; 463 464 #endif /* INITRD_IMAGE_SIZE */ 465 466 #ifdef DEBUG_LAST_STEPS 467 srm_printk("Doing 'runkernel()'...\n"); 468 #endif 469 runkernel(); 470 } 471 472 /* dummy function, should never be called. */ 473 void *__kmalloc(size_t size, gfp_t flags) 474 { 475 return (void *)NULL; 476 } 477