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Simon Glass476476e2015-08-04 12:33:52 -06001/*
2 * Copyright (c) 2015 Google, Inc
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 *
6 * EFI information obtained here:
7 * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES
8 *
Simon Glass96a8d402015-08-04 12:33:56 -06009 * Loads a payload (U-Boot) within the EFI environment. This is built as an
10 * EFI application. It can be built either in 32-bit or 64-bit mode.
Simon Glass476476e2015-08-04 12:33:52 -060011 */
12
13#include <common.h>
14#include <debug_uart.h>
15#include <efi.h>
16#include <efi_api.h>
17#include <errno.h>
18#include <ns16550.h>
19#include <asm/cpu.h>
20#include <asm/io.h>
21#include <linux/err.h>
22#include <linux/types.h>
23
24DECLARE_GLOBAL_DATA_PTR;
25
26#ifndef CONFIG_X86
27/*
28 * Problem areas:
29 * - putc() uses the ns16550 address directly and assumed I/O access. Many
30 * platforms will use memory access
31 * get_codeseg32() is only meaningful on x86
32 */
33#error "This file needs to be ported for use on architectures"
34#endif
35
36static struct efi_priv *global_priv;
37static bool use_uart;
38
39struct __packed desctab_info {
40 uint16_t limit;
41 uint64_t addr;
42 uint16_t pad;
43};
44
45/*
46 * EFI uses Unicode and we don't. The easiest way to get a sensible output
47 * function is to use the U-Boot debug UART. We use EFI's console output
48 * function where available, and assume the built-in UART after that. We rely
49 * on EFI to set up the UART for us and just bring in the functions here.
50 * This last bit is a bit icky, but it's only for debugging anyway. We could
51 * build in ns16550.c with some effort, but this is a payload loader after
52 * all.
53 *
54 * Note: We avoid using printf() so we don't need to bring in lib/vsprintf.c.
55 * That would require some refactoring since we already build this for U-Boot.
56 * Building an EFI shared library version would have to be a separate stem.
57 * That might push us to using the SPL framework to build this stub. However
58 * that would involve a round of EFI-specific changes in SPL. Worth
59 * considering if we start needing more U-Boot functionality. Note that we
60 * could then move get_codeseg32() to arch/x86/cpu/cpu.c.
61 */
Simon Glass97b05972015-10-18 19:51:23 -060062void _debug_uart_init(void)
Simon Glass476476e2015-08-04 12:33:52 -060063{
64}
65
66void putc(const char ch)
67{
Bin Meng075bb5c2016-03-17 23:59:03 -070068 if (ch == '\n')
69 putc('\r');
70
Simon Glass476476e2015-08-04 12:33:52 -060071 if (use_uart) {
72 NS16550_t com_port = (NS16550_t)0x3f8;
73
74 while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0)
75 ;
76 outb(ch, (ulong)&com_port->thr);
77 } else {
78 efi_putc(global_priv, ch);
79 }
Simon Glass476476e2015-08-04 12:33:52 -060080}
81
82void puts(const char *str)
83{
84 while (*str)
85 putc(*str++);
86}
87
88static void _debug_uart_putc(int ch)
89{
90 putc(ch);
91}
92
93DEBUG_UART_FUNCS
94
95void *memcpy(void *dest, const void *src, size_t size)
96{
97 unsigned char *dptr = dest;
98 const unsigned char *ptr = src;
99 const unsigned char *end = src + size;
100
101 while (ptr < end)
102 *dptr++ = *ptr++;
103
104 return dest;
105}
106
107void *memset(void *inptr, int ch, size_t size)
108{
109 char *ptr = inptr;
110 char *end = ptr + size;
111
112 while (ptr < end)
113 *ptr++ = ch;
114
115 return ptr;
116}
117
118static void jump_to_uboot(ulong cs32, ulong addr, ulong info)
119{
120#ifdef CONFIG_EFI_STUB_32BIT
121 /*
122 * U-Boot requires these parameters in registers, not on the stack.
123 * See _x86boot_start() for this code.
124 */
125 typedef void (*func_t)(int bist, int unused, ulong info)
126 __attribute__((regparm(3)));
127
128 ((func_t)addr)(0, 0, info);
129#else
Simon Glass96a8d402015-08-04 12:33:56 -0600130 cpu_call32(cs32, CONFIG_SYS_TEXT_BASE, info);
Simon Glass476476e2015-08-04 12:33:52 -0600131#endif
132}
133
Simon Glass96a8d402015-08-04 12:33:56 -0600134#ifdef CONFIG_EFI_STUB_64BIT
Simon Glass476476e2015-08-04 12:33:52 -0600135static void get_gdt(struct desctab_info *info)
136{
137 asm volatile ("sgdt %0" : : "m"(*info) : "memory");
138}
Simon Glass96a8d402015-08-04 12:33:56 -0600139#endif
Simon Glass476476e2015-08-04 12:33:52 -0600140
141static inline unsigned long read_cr3(void)
142{
143 unsigned long val;
144
145 asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory");
146 return val;
147}
148
149/**
150 * get_codeseg32() - Find the code segment to use for 32-bit code
151 *
152 * U-Boot only works in 32-bit mode at present, so when booting from 64-bit
153 * EFI we must first change to 32-bit mode. To do this we need to find the
154 * correct code segment to use (an entry in the Global Descriptor Table).
155 *
156 * @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found
157 */
158static int get_codeseg32(void)
159{
160 int cs32 = 0;
161
Simon Glass96a8d402015-08-04 12:33:56 -0600162#ifdef CONFIG_EFI_STUB_64BIT
163 struct desctab_info gdt;
164 uint64_t *ptr;
165 int i;
166
167 get_gdt(&gdt);
168 for (ptr = (uint64_t *)(unsigned long)gdt.addr, i = 0; i < gdt.limit;
169 i += 8, ptr++) {
170 uint64_t desc = *ptr;
171 uint64_t base, limit;
172
173 /*
174 * Check that the target U-Boot jump address is within the
175 * selector and that the selector is of the right type.
176 */
177 base = ((desc >> GDT_BASE_LOW_SHIFT) & GDT_BASE_LOW_MASK) |
178 ((desc >> GDT_BASE_HIGH_SHIFT) & GDT_BASE_HIGH_MASK)
179 << 16;
180 limit = ((desc >> GDT_LIMIT_LOW_SHIFT) & GDT_LIMIT_LOW_MASK) |
181 ((desc >> GDT_LIMIT_HIGH_SHIFT) & GDT_LIMIT_HIGH_MASK)
182 << 16;
183 base <<= 12; /* 4KB granularity */
184 limit <<= 12;
185 if ((desc & GDT_PRESENT) && (desc && GDT_NOTSYS) &&
186 !(desc & GDT_LONG) && (desc & GDT_4KB) &&
187 (desc & GDT_32BIT) && (desc & GDT_CODE) &&
188 CONFIG_SYS_TEXT_BASE > base &&
189 CONFIG_SYS_TEXT_BASE + CONFIG_SYS_MONITOR_LEN < limit
190 ) {
191 cs32 = i;
192 break;
193 }
194 }
195
196#ifdef DEBUG
197 puts("\ngdt: ");
198 printhex8(gdt.limit);
199 puts(", addr: ");
200 printhex8(gdt.addr >> 32);
201 printhex8(gdt.addr);
202 for (i = 0; i < gdt.limit; i += 8) {
203 uint32_t *ptr = (uint32_t *)((unsigned long)gdt.addr + i);
204
205 puts("\n");
206 printhex2(i);
207 puts(": ");
208 printhex8(ptr[1]);
209 puts(" ");
210 printhex8(ptr[0]);
211 }
212 puts("\n ");
213 puts("32-bit code segment: ");
214 printhex2(cs32);
215 puts("\n ");
216
217 puts("page_table: ");
218 printhex8(read_cr3());
219 puts("\n ");
220#endif
221 if (!cs32) {
222 puts("Can't find 32-bit code segment\n");
223 return -ENOENT;
224 }
225#endif
226
Simon Glass476476e2015-08-04 12:33:52 -0600227 return cs32;
228}
229
230static int setup_info_table(struct efi_priv *priv, int size)
231{
232 struct efi_info_hdr *info;
233 efi_status_t ret;
234
235 /* Get some memory for our info table */
236 priv->info_size = size;
237 info = efi_malloc(priv, priv->info_size, &ret);
238 if (ret) {
239 printhex2(ret);
240 puts(" No memory for info table: ");
241 return ret;
242 }
243
244 memset(info, '\0', sizeof(*info));
245 info->version = EFI_TABLE_VERSION;
246 info->hdr_size = sizeof(*info);
247 priv->info = info;
248 priv->next_hdr = (char *)info + info->hdr_size;
249
250 return 0;
251}
252
253static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type,
254 void *ptr1, int size1, void *ptr2, int size2)
255{
256 struct efi_entry_hdr *hdr = priv->next_hdr;
257
258 hdr->type = type;
259 hdr->size = size1 + size2;
260 hdr->addr = 0;
261 hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16);
262 priv->next_hdr += hdr->link;
263 memcpy(hdr + 1, ptr1, size1);
264 memcpy((void *)(hdr + 1) + size1, ptr2, size2);
265 priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info;
266}
267
268/**
269 * efi_main() - Start an EFI image
270 *
271 * This function is called by our EFI start-up code. It handles running
272 * U-Boot. If it returns, EFI will continue.
273 */
274efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
275{
276 struct efi_priv local_priv, *priv = &local_priv;
277 struct efi_boot_services *boot = sys_table->boottime;
278 struct efi_mem_desc *desc;
279 struct efi_entry_memmap map;
280 ulong key, desc_size, size;
281 efi_status_t ret;
282 u32 version;
283 int cs32;
284
285 ret = efi_init(priv, "Payload", image, sys_table);
286 if (ret) {
287 printhex2(ret); puts(" efi_init() failed\n");
288 return ret;
289 }
290 global_priv = priv;
291
292 cs32 = get_codeseg32();
293 if (cs32 < 0)
294 return EFI_UNSUPPORTED;
295
296 /* Get the memory map so we can switch off EFI */
297 size = 0;
298 ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version);
299 if (ret != EFI_BUFFER_TOO_SMALL) {
300 printhex2(BITS_PER_LONG);
301 printhex2(ret);
302 puts(" No memory map\n");
303 return ret;
304 }
305 size += 1024; /* Since doing a malloc() may change the memory map! */
306 desc = efi_malloc(priv, size, &ret);
307 if (!desc) {
308 printhex2(ret);
309 puts(" No memory for memory descriptor: ");
310 return ret;
311 }
312 ret = setup_info_table(priv, size + 128);
313 if (ret)
314 return ret;
315
316 ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version);
317 if (ret) {
318 printhex2(ret);
319 puts(" Can't get memory map\n");
320 return ret;
321 }
322
323 ret = boot->exit_boot_services(image, key);
324 if (ret) {
325 /*
326 * Unfortunately it happens that we cannot exit boot services
327 * the first time. But the second time it work. I don't know
328 * why but this seems to be a repeatable problem. To get
329 * around it, just try again.
330 */
331 printhex2(ret);
332 puts(" Can't exit boot services\n");
333 size = sizeof(desc);
334 ret = boot->get_memory_map(&size, desc, &key, &desc_size,
335 &version);
336 if (ret) {
337 printhex2(ret);
338 puts(" Can't get memory map\n");
339 return ret;
340 }
341 ret = boot->exit_boot_services(image, key);
342 if (ret) {
343 printhex2(ret);
344 puts(" Can't exit boot services 2\n");
345 return ret;
346 }
347 }
348
349 map.version = version;
350 map.desc_size = desc_size;
351 add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size);
352 add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0);
353
354 /* The EFI UART won't work now, switch to a debug one */
355 use_uart = true;
356
357 memcpy((void *)CONFIG_SYS_TEXT_BASE, _binary_u_boot_dtb_bin_start,
358 (ulong)_binary_u_boot_dtb_bin_end -
359 (ulong)_binary_u_boot_dtb_bin_start);
360
361#ifdef DEBUG
362 puts("EFI table at ");
363 printhex8((ulong)priv->info);
364 puts(" size ");
365 printhex8(priv->info->total_size);
366#endif
367 putc('\n');
368 jump_to_uboot(cs32, CONFIG_SYS_TEXT_BASE, (ulong)priv->info);
369
370 return EFI_LOAD_ERROR;
371}