1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Early boot support code for BootX bootloader
4  *
5  *  Copyright (C) 2005 Ben. Herrenschmidt (benh@kernel.crashing.org)
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/string.h>
10 #include <linux/init.h>
11 #include <generated/utsrelease.h>
12 #include <asm/sections.h>
13 #include <asm/prom.h>
14 #include <asm/page.h>
15 #include <asm/bootx.h>
16 #include <asm/btext.h>
17 #include <asm/io.h>
18 #include <asm/setup.h>
19 
20 #undef DEBUG
21 #define SET_BOOT_BAT
22 
23 #ifdef DEBUG
24 #define DBG(fmt...) do { bootx_printf(fmt); } while(0)
25 #else
26 #define DBG(fmt...) do { } while(0)
27 #endif
28 
29 extern void __start(unsigned long r3, unsigned long r4, unsigned long r5);
30 
31 static unsigned long __initdata bootx_dt_strbase;
32 static unsigned long __initdata bootx_dt_strend;
33 static unsigned long __initdata bootx_node_chosen;
34 static boot_infos_t * __initdata bootx_info;
35 static char __initdata bootx_disp_path[256];
36 
37 /* Is boot-info compatible ? */
38 #define BOOT_INFO_IS_COMPATIBLE(bi) \
39 	((bi)->compatible_version <= BOOT_INFO_VERSION)
40 #define BOOT_INFO_IS_V2_COMPATIBLE(bi)	((bi)->version >= 2)
41 #define BOOT_INFO_IS_V4_COMPATIBLE(bi)	((bi)->version >= 4)
42 
43 #ifdef CONFIG_BOOTX_TEXT
44 static void __init bootx_printf(const char *format, ...)
45 {
46 	const char *p, *q, *s;
47 	va_list args;
48 	unsigned long v;
49 
50 	va_start(args, format);
51 	for (p = format; *p != 0; p = q) {
52 		for (q = p; *q != 0 && *q != '\n' && *q != '%'; ++q)
53 			;
54 		if (q > p)
55 			btext_drawtext(p, q - p);
56 		if (*q == 0)
57 			break;
58 		if (*q == '\n') {
59 			++q;
60 			btext_flushline();
61 			btext_drawstring("\r\n");
62 			btext_flushline();
63 			continue;
64 		}
65 		++q;
66 		if (*q == 0)
67 			break;
68 		switch (*q) {
69 		case 's':
70 			++q;
71 			s = va_arg(args, const char *);
72 			if (s == NULL)
73 				s = "<NULL>";
74 			btext_drawstring(s);
75 			break;
76 		case 'x':
77 			++q;
78 			v = va_arg(args, unsigned long);
79 			btext_drawhex(v);
80 			break;
81 		}
82 	}
83 	va_end(args);
84 }
85 #else /* CONFIG_BOOTX_TEXT */
86 static void __init bootx_printf(const char *format, ...) {}
87 #endif /* CONFIG_BOOTX_TEXT */
88 
89 static void * __init bootx_early_getprop(unsigned long base,
90 					 unsigned long node,
91 					 char *prop)
92 {
93 	struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
94 	u32 *ppp = &np->properties;
95 
96 	while(*ppp) {
97 		struct bootx_dt_prop *pp =
98 			(struct bootx_dt_prop *)(base + *ppp);
99 
100 		if (strcmp((char *)((unsigned long)pp->name + base),
101 			   prop) == 0) {
102 			return (void *)((unsigned long)pp->value + base);
103 		}
104 		ppp = &pp->next;
105 	}
106 	return NULL;
107 }
108 
109 #define dt_push_token(token, mem) \
110 	do { \
111 		*(mem) = ALIGN(*(mem),4); \
112 		*((u32 *)*(mem)) = token; \
113 		*(mem) += 4; \
114 	} while(0)
115 
116 static unsigned long __init bootx_dt_find_string(char *str)
117 {
118 	char *s, *os;
119 
120 	s = os = (char *)bootx_dt_strbase;
121 	s += 4;
122 	while (s <  (char *)bootx_dt_strend) {
123 		if (strcmp(s, str) == 0)
124 			return s - os;
125 		s += strlen(s) + 1;
126 	}
127 	return 0;
128 }
129 
130 static void __init bootx_dt_add_prop(char *name, void *data, int size,
131 				  unsigned long *mem_end)
132 {
133 	unsigned long soff = bootx_dt_find_string(name);
134 	if (data == NULL)
135 		size = 0;
136 	if (soff == 0) {
137 		bootx_printf("WARNING: Can't find string index for <%s>\n",
138 			     name);
139 		return;
140 	}
141 	if (size > 0x20000) {
142 		bootx_printf("WARNING: ignoring large property ");
143 		bootx_printf("%s length 0x%x\n", name, size);
144 		return;
145 	}
146 	dt_push_token(OF_DT_PROP, mem_end);
147 	dt_push_token(size, mem_end);
148 	dt_push_token(soff, mem_end);
149 
150 	/* push property content */
151 	if (size && data) {
152 		memcpy((void *)*mem_end, data, size);
153 		*mem_end = ALIGN(*mem_end + size, 4);
154 	}
155 }
156 
157 static void __init bootx_add_chosen_props(unsigned long base,
158 					  unsigned long *mem_end)
159 {
160 	u32 val;
161 
162 	bootx_dt_add_prop("linux,bootx", NULL, 0, mem_end);
163 
164 	if (bootx_info->kernelParamsOffset) {
165 		char *args = (char *)((unsigned long)bootx_info) +
166 			bootx_info->kernelParamsOffset;
167 		bootx_dt_add_prop("bootargs", args, strlen(args) + 1, mem_end);
168 	}
169 	if (bootx_info->ramDisk) {
170 		val = ((unsigned long)bootx_info) + bootx_info->ramDisk;
171 		bootx_dt_add_prop("linux,initrd-start", &val, 4, mem_end);
172 		val += bootx_info->ramDiskSize;
173 		bootx_dt_add_prop("linux,initrd-end", &val, 4, mem_end);
174 	}
175 	if (strlen(bootx_disp_path))
176 		bootx_dt_add_prop("linux,stdout-path", bootx_disp_path,
177 				  strlen(bootx_disp_path) + 1, mem_end);
178 }
179 
180 static void __init bootx_add_display_props(unsigned long base,
181 					   unsigned long *mem_end,
182 					   int has_real_node)
183 {
184 	boot_infos_t *bi = bootx_info;
185 	u32 tmp;
186 
187 	if (has_real_node) {
188 		bootx_dt_add_prop("linux,boot-display", NULL, 0, mem_end);
189 		bootx_dt_add_prop("linux,opened", NULL, 0, mem_end);
190 	} else
191 		bootx_dt_add_prop("linux,bootx-noscreen", NULL, 0, mem_end);
192 
193 	tmp = bi->dispDeviceDepth;
194 	bootx_dt_add_prop("linux,bootx-depth", &tmp, 4, mem_end);
195 	tmp = bi->dispDeviceRect[2] - bi->dispDeviceRect[0];
196 	bootx_dt_add_prop("linux,bootx-width", &tmp, 4, mem_end);
197 	tmp = bi->dispDeviceRect[3] - bi->dispDeviceRect[1];
198 	bootx_dt_add_prop("linux,bootx-height", &tmp, 4, mem_end);
199 	tmp = bi->dispDeviceRowBytes;
200 	bootx_dt_add_prop("linux,bootx-linebytes", &tmp, 4, mem_end);
201 	tmp = (u32)bi->dispDeviceBase;
202 	if (tmp == 0)
203 		tmp = (u32)bi->logicalDisplayBase;
204 	tmp += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
205 	tmp += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
206 	bootx_dt_add_prop("linux,bootx-addr", &tmp, 4, mem_end);
207 }
208 
209 static void __init bootx_dt_add_string(char *s, unsigned long *mem_end)
210 {
211 	unsigned int l = strlen(s) + 1;
212 	memcpy((void *)*mem_end, s, l);
213 	bootx_dt_strend = *mem_end = *mem_end + l;
214 }
215 
216 static void __init bootx_scan_dt_build_strings(unsigned long base,
217 					       unsigned long node,
218 					       unsigned long *mem_end)
219 {
220 	struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
221 	u32 *cpp, *ppp = &np->properties;
222 	unsigned long soff;
223 	char *namep;
224 
225 	/* Keep refs to known nodes */
226 	namep = np->full_name ? (char *)(base + np->full_name) : NULL;
227        	if (namep == NULL) {
228 		bootx_printf("Node without a full name !\n");
229 		namep = "";
230 	}
231 	DBG("* strings: %s\n", namep);
232 
233 	if (!strcmp(namep, "/chosen")) {
234 		DBG(" detected /chosen ! adding properties names !\n");
235 		bootx_dt_add_string("linux,bootx", mem_end);
236 		bootx_dt_add_string("linux,stdout-path", mem_end);
237 		bootx_dt_add_string("linux,initrd-start", mem_end);
238 		bootx_dt_add_string("linux,initrd-end", mem_end);
239 		bootx_dt_add_string("bootargs", mem_end);
240 		bootx_node_chosen = node;
241 	}
242 	if (node == bootx_info->dispDeviceRegEntryOffset) {
243 		DBG(" detected display ! adding properties names !\n");
244 		bootx_dt_add_string("linux,boot-display", mem_end);
245 		bootx_dt_add_string("linux,opened", mem_end);
246 		strlcpy(bootx_disp_path, namep, sizeof(bootx_disp_path));
247 	}
248 
249 	/* get and store all property names */
250 	while (*ppp) {
251 		struct bootx_dt_prop *pp =
252 			(struct bootx_dt_prop *)(base + *ppp);
253 
254 		namep = pp->name ? (char *)(base + pp->name) : NULL;
255  		if (namep == NULL || strcmp(namep, "name") == 0)
256  			goto next;
257 		/* get/create string entry */
258 		soff = bootx_dt_find_string(namep);
259 		if (soff == 0)
260 			bootx_dt_add_string(namep, mem_end);
261 	next:
262 		ppp = &pp->next;
263 	}
264 
265 	/* do all our children */
266 	cpp = &np->child;
267 	while(*cpp) {
268 		np = (struct bootx_dt_node *)(base + *cpp);
269 		bootx_scan_dt_build_strings(base, *cpp, mem_end);
270 		cpp = &np->sibling;
271 	}
272 }
273 
274 static void __init bootx_scan_dt_build_struct(unsigned long base,
275 					      unsigned long node,
276 					      unsigned long *mem_end)
277 {
278 	struct bootx_dt_node *np = (struct bootx_dt_node *)(base + node);
279 	u32 *cpp, *ppp = &np->properties;
280 	char *namep, *p, *ep, *lp;
281 	int l;
282 
283 	dt_push_token(OF_DT_BEGIN_NODE, mem_end);
284 
285 	/* get the node's full name */
286 	namep = np->full_name ? (char *)(base + np->full_name) : NULL;
287 	if (namep == NULL)
288 		namep = "";
289 	l = strlen(namep);
290 
291 	DBG("* struct: %s\n", namep);
292 
293 	/* Fixup an Apple bug where they have bogus \0 chars in the
294 	 * middle of the path in some properties, and extract
295 	 * the unit name (everything after the last '/').
296 	 */
297 	memcpy((void *)*mem_end, namep, l + 1);
298 	namep = (char *)*mem_end;
299 	for (lp = p = namep, ep = namep + l; p < ep; p++) {
300 		if (*p == '/')
301 			lp = namep;
302 		else if (*p != 0)
303 			*lp++ = *p;
304 	}
305 	*lp = 0;
306 	*mem_end = ALIGN((unsigned long)lp + 1, 4);
307 
308 	/* get and store all properties */
309 	while (*ppp) {
310 		struct bootx_dt_prop *pp =
311 			(struct bootx_dt_prop *)(base + *ppp);
312 
313 		namep = pp->name ? (char *)(base + pp->name) : NULL;
314 		/* Skip "name" */
315  		if (namep == NULL || !strcmp(namep, "name"))
316  			goto next;
317 		/* Skip "bootargs" in /chosen too as we replace it */
318 		if (node == bootx_node_chosen && !strcmp(namep, "bootargs"))
319 			goto next;
320 
321 		/* push property head */
322 		bootx_dt_add_prop(namep,
323 				  pp->value ? (void *)(base + pp->value): NULL,
324 				  pp->length, mem_end);
325 	next:
326 		ppp = &pp->next;
327 	}
328 
329 	if (node == bootx_node_chosen) {
330 		bootx_add_chosen_props(base, mem_end);
331 		if (bootx_info->dispDeviceRegEntryOffset == 0)
332 			bootx_add_display_props(base, mem_end, 0);
333 	}
334 	else if (node == bootx_info->dispDeviceRegEntryOffset)
335 		bootx_add_display_props(base, mem_end, 1);
336 
337 	/* do all our children */
338 	cpp = &np->child;
339 	while(*cpp) {
340 		np = (struct bootx_dt_node *)(base + *cpp);
341 		bootx_scan_dt_build_struct(base, *cpp, mem_end);
342 		cpp = &np->sibling;
343 	}
344 
345 	dt_push_token(OF_DT_END_NODE, mem_end);
346 }
347 
348 static unsigned long __init bootx_flatten_dt(unsigned long start)
349 {
350 	boot_infos_t *bi = bootx_info;
351 	unsigned long mem_start, mem_end;
352 	struct boot_param_header *hdr;
353 	unsigned long base;
354 	u64 *rsvmap;
355 
356 	/* Start using memory after the big blob passed by BootX, get
357 	 * some space for the header
358 	 */
359 	mem_start = mem_end = ALIGN(((unsigned long)bi) + start, 4);
360 	DBG("Boot params header at: %x\n", mem_start);
361 	hdr = (struct boot_param_header *)mem_start;
362 	mem_end += sizeof(struct boot_param_header);
363 	rsvmap = (u64 *)(ALIGN(mem_end, 8));
364 	hdr->off_mem_rsvmap = ((unsigned long)rsvmap) - mem_start;
365 	mem_end = ((unsigned long)rsvmap) + 8 * sizeof(u64);
366 
367 	/* Get base of tree */
368 	base = ((unsigned long)bi) + bi->deviceTreeOffset;
369 
370 	/* Build string array */
371 	DBG("Building string array at: %x\n", mem_end);
372 	DBG("Device Tree Base=%x\n", base);
373 	bootx_dt_strbase = mem_end;
374 	mem_end += 4;
375 	bootx_dt_strend = mem_end;
376 	bootx_scan_dt_build_strings(base, 4, &mem_end);
377 	/* Add some strings */
378 	bootx_dt_add_string("linux,bootx-noscreen", &mem_end);
379 	bootx_dt_add_string("linux,bootx-depth", &mem_end);
380 	bootx_dt_add_string("linux,bootx-width", &mem_end);
381 	bootx_dt_add_string("linux,bootx-height", &mem_end);
382 	bootx_dt_add_string("linux,bootx-linebytes", &mem_end);
383 	bootx_dt_add_string("linux,bootx-addr", &mem_end);
384 	/* Wrap up strings */
385 	hdr->off_dt_strings = bootx_dt_strbase - mem_start;
386 	hdr->dt_strings_size = bootx_dt_strend - bootx_dt_strbase;
387 
388 	/* Build structure */
389 	mem_end = ALIGN(mem_end, 16);
390 	DBG("Building device tree structure at: %x\n", mem_end);
391 	hdr->off_dt_struct = mem_end - mem_start;
392 	bootx_scan_dt_build_struct(base, 4, &mem_end);
393 	dt_push_token(OF_DT_END, &mem_end);
394 
395 	/* Finish header */
396 	hdr->boot_cpuid_phys = 0;
397 	hdr->magic = OF_DT_HEADER;
398 	hdr->totalsize = mem_end - mem_start;
399 	hdr->version = OF_DT_VERSION;
400 	/* Version 16 is not backward compatible */
401 	hdr->last_comp_version = 0x10;
402 
403 	/* Reserve the whole thing and copy the reserve map in, we
404 	 * also bump mem_reserve_cnt to cause further reservations to
405 	 * fail since it's too late.
406 	 */
407 	mem_end = ALIGN(mem_end, PAGE_SIZE);
408 	DBG("End of boot params: %x\n", mem_end);
409 	rsvmap[0] = mem_start;
410 	rsvmap[1] = mem_end;
411 	if (bootx_info->ramDisk) {
412 		rsvmap[2] = ((unsigned long)bootx_info) + bootx_info->ramDisk;
413 		rsvmap[3] = rsvmap[2] + bootx_info->ramDiskSize;
414 		rsvmap[4] = 0;
415 		rsvmap[5] = 0;
416 	} else {
417 		rsvmap[2] = 0;
418 		rsvmap[3] = 0;
419 	}
420 
421 	return (unsigned long)hdr;
422 }
423 
424 
425 #ifdef CONFIG_BOOTX_TEXT
426 static void __init btext_welcome(boot_infos_t *bi)
427 {
428 	unsigned long flags;
429 	unsigned long pvr;
430 
431 	bootx_printf("Welcome to Linux, kernel " UTS_RELEASE "\n");
432 	bootx_printf("\nlinked at        : 0x%x", KERNELBASE);
433 	bootx_printf("\nframe buffer at  : 0x%x", bi->dispDeviceBase);
434 	bootx_printf(" (phys), 0x%x", bi->logicalDisplayBase);
435 	bootx_printf(" (log)");
436 	bootx_printf("\nklimit           : 0x%x",(unsigned long)klimit);
437 	bootx_printf("\nboot_info at     : 0x%x", bi);
438 	__asm__ __volatile__ ("mfmsr %0" : "=r" (flags));
439 	bootx_printf("\nMSR              : 0x%x", flags);
440 	__asm__ __volatile__ ("mfspr %0, 287" : "=r" (pvr));
441 	bootx_printf("\nPVR              : 0x%x", pvr);
442 	pvr >>= 16;
443 	if (pvr > 1) {
444 	    __asm__ __volatile__ ("mfspr %0, 1008" : "=r" (flags));
445 	    bootx_printf("\nHID0             : 0x%x", flags);
446 	}
447 	if (pvr == 8 || pvr == 12 || pvr == 0x800c) {
448 	    __asm__ __volatile__ ("mfspr %0, 1019" : "=r" (flags));
449 	    bootx_printf("\nICTC             : 0x%x", flags);
450 	}
451 #ifdef DEBUG
452 	bootx_printf("\n\n");
453 	bootx_printf("bi->deviceTreeOffset   : 0x%x\n",
454 		     bi->deviceTreeOffset);
455 	bootx_printf("bi->deviceTreeSize     : 0x%x\n",
456 		     bi->deviceTreeSize);
457 #endif
458 	bootx_printf("\n\n");
459 }
460 #endif /* CONFIG_BOOTX_TEXT */
461 
462 void __init bootx_init(unsigned long r3, unsigned long r4)
463 {
464 	boot_infos_t *bi = (boot_infos_t *) r4;
465 	unsigned long hdr;
466 	unsigned long space;
467 	unsigned long ptr;
468 	char *model;
469 	unsigned long offset = reloc_offset();
470 
471 	reloc_got2(offset);
472 
473 	bootx_info = bi;
474 
475 	/* We haven't cleared any bss at this point, make sure
476 	 * what we need is initialized
477 	 */
478 	bootx_dt_strbase = bootx_dt_strend = 0;
479 	bootx_node_chosen = 0;
480 	bootx_disp_path[0] = 0;
481 
482 	if (!BOOT_INFO_IS_V2_COMPATIBLE(bi))
483 		bi->logicalDisplayBase = bi->dispDeviceBase;
484 
485 	/* Fixup depth 16 -> 15 as that's what MacOS calls 16bpp */
486 	if (bi->dispDeviceDepth == 16)
487 		bi->dispDeviceDepth = 15;
488 
489 
490 #ifdef CONFIG_BOOTX_TEXT
491 	ptr = (unsigned long)bi->logicalDisplayBase;
492 	ptr += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
493 	ptr += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
494 	btext_setup_display(bi->dispDeviceRect[2] - bi->dispDeviceRect[0],
495 			    bi->dispDeviceRect[3] - bi->dispDeviceRect[1],
496 			    bi->dispDeviceDepth, bi->dispDeviceRowBytes,
497 			    (unsigned long)bi->logicalDisplayBase);
498 	btext_clearscreen();
499 	btext_flushscreen();
500 #endif /* CONFIG_BOOTX_TEXT */
501 
502 	/*
503 	 * Test if boot-info is compatible.  Done only in config
504 	 * CONFIG_BOOTX_TEXT since there is nothing much we can do
505 	 * with an incompatible version, except display a message
506 	 * and eventually hang the processor...
507 	 *
508 	 * I'll try to keep enough of boot-info compatible in the
509 	 * future to always allow display of this message;
510 	 */
511 	if (!BOOT_INFO_IS_COMPATIBLE(bi)) {
512 		bootx_printf(" !!! WARNING - Incompatible version"
513 			     " of BootX !!!\n\n\n");
514 		for (;;)
515 			;
516 	}
517 	if (bi->architecture != BOOT_ARCH_PCI) {
518 		bootx_printf(" !!! WARNING - Unsupported machine"
519 			     " architecture !\n");
520 		for (;;)
521 			;
522 	}
523 
524 #ifdef CONFIG_BOOTX_TEXT
525 	btext_welcome(bi);
526 #endif
527 
528 	/* New BootX enters kernel with MMU off, i/os are not allowed
529 	 * here. This hack will have been done by the boostrap anyway.
530 	 */
531 	if (bi->version < 4) {
532 		/*
533 		 * XXX If this is an iMac, turn off the USB controller.
534 		 */
535 		model = (char *) bootx_early_getprop(r4 + bi->deviceTreeOffset,
536 						     4, "model");
537 		if (model
538 		    && (strcmp(model, "iMac,1") == 0
539 			|| strcmp(model, "PowerMac1,1") == 0)) {
540 			bootx_printf("iMac,1 detected, shutting down USB\n");
541 			out_le32((unsigned __iomem *)0x80880008, 1);	/* XXX */
542 		}
543 	}
544 
545 	/* Get a pointer that points above the device tree, args, ramdisk,
546 	 * etc... to use for generating the flattened tree
547 	 */
548 	if (bi->version < 5) {
549 		space = bi->deviceTreeOffset + bi->deviceTreeSize;
550 		if (bi->ramDisk >= space)
551 			space = bi->ramDisk + bi->ramDiskSize;
552 	} else
553 		space = bi->totalParamsSize;
554 
555 	bootx_printf("Total space used by parameters & ramdisk: 0x%x\n", space);
556 
557 	/* New BootX will have flushed all TLBs and enters kernel with
558 	 * MMU switched OFF, so this should not be useful anymore.
559 	 */
560 	if (bi->version < 4) {
561 		unsigned long x __maybe_unused;
562 
563 		bootx_printf("Touching pages...\n");
564 
565 		/*
566 		 * Touch each page to make sure the PTEs for them
567 		 * are in the hash table - the aim is to try to avoid
568 		 * getting DSI exceptions while copying the kernel image.
569 		 */
570 		for (ptr = ((unsigned long) &_stext) & PAGE_MASK;
571 		     ptr < (unsigned long)bi + space; ptr += PAGE_SIZE)
572 			x = *(volatile unsigned long *)ptr;
573 	}
574 
575 	/* Ok, now we need to generate a flattened device-tree to pass
576 	 * to the kernel
577 	 */
578 	bootx_printf("Preparing boot params...\n");
579 
580 	hdr = bootx_flatten_dt(space);
581 
582 #ifdef CONFIG_BOOTX_TEXT
583 #ifdef SET_BOOT_BAT
584 	bootx_printf("Preparing BAT...\n");
585 	btext_prepare_BAT();
586 #else
587 	btext_unmap();
588 #endif
589 #endif
590 
591 	reloc_got2(-offset);
592 
593 	__start(hdr, KERNELBASE + offset, 0);
594 }
595