blob: e13870931e9be33421e2af62fa1917ee7aeded11 [file] [log] [blame]
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{
68 if (use_uart) {
69 NS16550_t com_port = (NS16550_t)0x3f8;
70
71 while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0)
72 ;
73 outb(ch, (ulong)&com_port->thr);
74 } else {
75 efi_putc(global_priv, ch);
76 }
77 if (ch == '\n')
78 putc('\r');
79}
80
81void puts(const char *str)
82{
83 while (*str)
84 putc(*str++);
85}
86
87static void _debug_uart_putc(int ch)
88{
89 putc(ch);
90}
91
92DEBUG_UART_FUNCS
93
94void *memcpy(void *dest, const void *src, size_t size)
95{
96 unsigned char *dptr = dest;
97 const unsigned char *ptr = src;
98 const unsigned char *end = src + size;
99
100 while (ptr < end)
101 *dptr++ = *ptr++;
102
103 return dest;
104}
105
106void *memset(void *inptr, int ch, size_t size)
107{
108 char *ptr = inptr;
109 char *end = ptr + size;
110
111 while (ptr < end)
112 *ptr++ = ch;
113
114 return ptr;
115}
116
117static void jump_to_uboot(ulong cs32, ulong addr, ulong info)
118{
119#ifdef CONFIG_EFI_STUB_32BIT
120 /*
121 * U-Boot requires these parameters in registers, not on the stack.
122 * See _x86boot_start() for this code.
123 */
124 typedef void (*func_t)(int bist, int unused, ulong info)
125 __attribute__((regparm(3)));
126
127 ((func_t)addr)(0, 0, info);
128#else
Simon Glass96a8d402015-08-04 12:33:56 -0600129 cpu_call32(cs32, CONFIG_SYS_TEXT_BASE, info);
Simon Glass476476e2015-08-04 12:33:52 -0600130#endif
131}
132
Simon Glass96a8d402015-08-04 12:33:56 -0600133#ifdef CONFIG_EFI_STUB_64BIT
Simon Glass476476e2015-08-04 12:33:52 -0600134static void get_gdt(struct desctab_info *info)
135{
136 asm volatile ("sgdt %0" : : "m"(*info) : "memory");
137}
Simon Glass96a8d402015-08-04 12:33:56 -0600138#endif
Simon Glass476476e2015-08-04 12:33:52 -0600139
140static inline unsigned long read_cr3(void)
141{
142 unsigned long val;
143
144 asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory");
145 return val;
146}
147
148/**
149 * get_codeseg32() - Find the code segment to use for 32-bit code
150 *
151 * U-Boot only works in 32-bit mode at present, so when booting from 64-bit
152 * EFI we must first change to 32-bit mode. To do this we need to find the
153 * correct code segment to use (an entry in the Global Descriptor Table).
154 *
155 * @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found
156 */
157static int get_codeseg32(void)
158{
159 int cs32 = 0;
160
Simon Glass96a8d402015-08-04 12:33:56 -0600161#ifdef CONFIG_EFI_STUB_64BIT
162 struct desctab_info gdt;
163 uint64_t *ptr;
164 int i;
165
166 get_gdt(&gdt);
167 for (ptr = (uint64_t *)(unsigned long)gdt.addr, i = 0; i < gdt.limit;
168 i += 8, ptr++) {
169 uint64_t desc = *ptr;
170 uint64_t base, limit;
171
172 /*
173 * Check that the target U-Boot jump address is within the
174 * selector and that the selector is of the right type.
175 */
176 base = ((desc >> GDT_BASE_LOW_SHIFT) & GDT_BASE_LOW_MASK) |
177 ((desc >> GDT_BASE_HIGH_SHIFT) & GDT_BASE_HIGH_MASK)
178 << 16;
179 limit = ((desc >> GDT_LIMIT_LOW_SHIFT) & GDT_LIMIT_LOW_MASK) |
180 ((desc >> GDT_LIMIT_HIGH_SHIFT) & GDT_LIMIT_HIGH_MASK)
181 << 16;
182 base <<= 12; /* 4KB granularity */
183 limit <<= 12;
184 if ((desc & GDT_PRESENT) && (desc && GDT_NOTSYS) &&
185 !(desc & GDT_LONG) && (desc & GDT_4KB) &&
186 (desc & GDT_32BIT) && (desc & GDT_CODE) &&
187 CONFIG_SYS_TEXT_BASE > base &&
188 CONFIG_SYS_TEXT_BASE + CONFIG_SYS_MONITOR_LEN < limit
189 ) {
190 cs32 = i;
191 break;
192 }
193 }
194
195#ifdef DEBUG
196 puts("\ngdt: ");
197 printhex8(gdt.limit);
198 puts(", addr: ");
199 printhex8(gdt.addr >> 32);
200 printhex8(gdt.addr);
201 for (i = 0; i < gdt.limit; i += 8) {
202 uint32_t *ptr = (uint32_t *)((unsigned long)gdt.addr + i);
203
204 puts("\n");
205 printhex2(i);
206 puts(": ");
207 printhex8(ptr[1]);
208 puts(" ");
209 printhex8(ptr[0]);
210 }
211 puts("\n ");
212 puts("32-bit code segment: ");
213 printhex2(cs32);
214 puts("\n ");
215
216 puts("page_table: ");
217 printhex8(read_cr3());
218 puts("\n ");
219#endif
220 if (!cs32) {
221 puts("Can't find 32-bit code segment\n");
222 return -ENOENT;
223 }
224#endif
225
Simon Glass476476e2015-08-04 12:33:52 -0600226 return cs32;
227}
228
229static int setup_info_table(struct efi_priv *priv, int size)
230{
231 struct efi_info_hdr *info;
232 efi_status_t ret;
233
234 /* Get some memory for our info table */
235 priv->info_size = size;
236 info = efi_malloc(priv, priv->info_size, &ret);
237 if (ret) {
238 printhex2(ret);
239 puts(" No memory for info table: ");
240 return ret;
241 }
242
243 memset(info, '\0', sizeof(*info));
244 info->version = EFI_TABLE_VERSION;
245 info->hdr_size = sizeof(*info);
246 priv->info = info;
247 priv->next_hdr = (char *)info + info->hdr_size;
248
249 return 0;
250}
251
252static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type,
253 void *ptr1, int size1, void *ptr2, int size2)
254{
255 struct efi_entry_hdr *hdr = priv->next_hdr;
256
257 hdr->type = type;
258 hdr->size = size1 + size2;
259 hdr->addr = 0;
260 hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16);
261 priv->next_hdr += hdr->link;
262 memcpy(hdr + 1, ptr1, size1);
263 memcpy((void *)(hdr + 1) + size1, ptr2, size2);
264 priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info;
265}
266
267/**
268 * efi_main() - Start an EFI image
269 *
270 * This function is called by our EFI start-up code. It handles running
271 * U-Boot. If it returns, EFI will continue.
272 */
273efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
274{
275 struct efi_priv local_priv, *priv = &local_priv;
276 struct efi_boot_services *boot = sys_table->boottime;
277 struct efi_mem_desc *desc;
278 struct efi_entry_memmap map;
279 ulong key, desc_size, size;
280 efi_status_t ret;
281 u32 version;
282 int cs32;
283
284 ret = efi_init(priv, "Payload", image, sys_table);
285 if (ret) {
286 printhex2(ret); puts(" efi_init() failed\n");
287 return ret;
288 }
289 global_priv = priv;
290
291 cs32 = get_codeseg32();
292 if (cs32 < 0)
293 return EFI_UNSUPPORTED;
294
295 /* Get the memory map so we can switch off EFI */
296 size = 0;
297 ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version);
298 if (ret != EFI_BUFFER_TOO_SMALL) {
299 printhex2(BITS_PER_LONG);
300 printhex2(ret);
301 puts(" No memory map\n");
302 return ret;
303 }
304 size += 1024; /* Since doing a malloc() may change the memory map! */
305 desc = efi_malloc(priv, size, &ret);
306 if (!desc) {
307 printhex2(ret);
308 puts(" No memory for memory descriptor: ");
309 return ret;
310 }
311 ret = setup_info_table(priv, size + 128);
312 if (ret)
313 return ret;
314
315 ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version);
316 if (ret) {
317 printhex2(ret);
318 puts(" Can't get memory map\n");
319 return ret;
320 }
321
322 ret = boot->exit_boot_services(image, key);
323 if (ret) {
324 /*
325 * Unfortunately it happens that we cannot exit boot services
326 * the first time. But the second time it work. I don't know
327 * why but this seems to be a repeatable problem. To get
328 * around it, just try again.
329 */
330 printhex2(ret);
331 puts(" Can't exit boot services\n");
332 size = sizeof(desc);
333 ret = boot->get_memory_map(&size, desc, &key, &desc_size,
334 &version);
335 if (ret) {
336 printhex2(ret);
337 puts(" Can't get memory map\n");
338 return ret;
339 }
340 ret = boot->exit_boot_services(image, key);
341 if (ret) {
342 printhex2(ret);
343 puts(" Can't exit boot services 2\n");
344 return ret;
345 }
346 }
347
348 map.version = version;
349 map.desc_size = desc_size;
350 add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size);
351 add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0);
352
353 /* The EFI UART won't work now, switch to a debug one */
354 use_uart = true;
355
356 memcpy((void *)CONFIG_SYS_TEXT_BASE, _binary_u_boot_dtb_bin_start,
357 (ulong)_binary_u_boot_dtb_bin_end -
358 (ulong)_binary_u_boot_dtb_bin_start);
359
360#ifdef DEBUG
361 puts("EFI table at ");
362 printhex8((ulong)priv->info);
363 puts(" size ");
364 printhex8(priv->info->total_size);
365#endif
366 putc('\n');
367 jump_to_uboot(cs32, CONFIG_SYS_TEXT_BASE, (ulong)priv->info);
368
369 return EFI_LOAD_ERROR;
370}