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