| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Copyright (c) 2015 Google, Inc |
| * |
| * EFI information obtained here: |
| * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES |
| * |
| * Loads a payload (U-Boot) within the EFI environment. This is built as an |
| * EFI application. It can be built either in 32-bit or 64-bit mode. |
| */ |
| |
| #include <common.h> |
| #include <debug_uart.h> |
| #include <efi.h> |
| #include <efi_api.h> |
| #include <errno.h> |
| #include <malloc.h> |
| #include <ns16550.h> |
| #include <asm/cpu.h> |
| #include <asm/io.h> |
| #include <linux/err.h> |
| #include <linux/types.h> |
| |
| #ifndef CONFIG_X86 |
| /* |
| * Problem areas: |
| * - putc() uses the ns16550 address directly and assumed I/O access. Many |
| * platforms will use memory access |
| * get_codeseg32() is only meaningful on x86 |
| */ |
| #error "This file needs to be ported for use on architectures" |
| #endif |
| |
| static bool use_uart; |
| |
| struct __packed desctab_info { |
| uint16_t limit; |
| uint64_t addr; |
| uint16_t pad; |
| }; |
| |
| /* |
| * EFI uses Unicode and we don't. The easiest way to get a sensible output |
| * function is to use the U-Boot debug UART. We use EFI's console output |
| * function where available, and assume the built-in UART after that. We rely |
| * on EFI to set up the UART for us and just bring in the functions here. |
| * This last bit is a bit icky, but it's only for debugging anyway. We could |
| * build in ns16550.c with some effort, but this is a payload loader after |
| * all. |
| * |
| * Note: We avoid using printf() so we don't need to bring in lib/vsprintf.c. |
| * That would require some refactoring since we already build this for U-Boot. |
| * Building an EFI shared library version would have to be a separate stem. |
| * That might push us to using the SPL framework to build this stub. However |
| * that would involve a round of EFI-specific changes in SPL. Worth |
| * considering if we start needing more U-Boot functionality. Note that we |
| * could then move get_codeseg32() to arch/x86/cpu/cpu.c. |
| */ |
| void _debug_uart_init(void) |
| { |
| } |
| |
| void putc(const char ch) |
| { |
| struct efi_priv *priv = efi_get_priv(); |
| |
| if (ch == '\n') |
| putc('\r'); |
| |
| if (use_uart) { |
| struct ns16550 *com_port = (struct ns16550 *)0x3f8; |
| |
| while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0) |
| ; |
| outb(ch, (ulong)&com_port->thr); |
| } else { |
| efi_putc(priv, ch); |
| } |
| } |
| |
| void puts(const char *str) |
| { |
| while (*str) |
| putc(*str++); |
| } |
| |
| static void _debug_uart_putc(int ch) |
| { |
| putc(ch); |
| } |
| |
| DEBUG_UART_FUNCS |
| |
| void *memcpy(void *dest, const void *src, size_t size) |
| { |
| unsigned char *dptr = dest; |
| const unsigned char *ptr = src; |
| const unsigned char *end = src + size; |
| |
| while (ptr < end) |
| *dptr++ = *ptr++; |
| |
| return dest; |
| } |
| |
| void *memset(void *inptr, int ch, size_t size) |
| { |
| char *ptr = inptr; |
| char *end = ptr + size; |
| |
| while (ptr < end) |
| *ptr++ = ch; |
| |
| return ptr; |
| } |
| |
| static void jump_to_uboot(ulong cs32, ulong addr, ulong info) |
| { |
| #ifdef CONFIG_EFI_STUB_32BIT |
| /* |
| * U-Boot requires these parameters in registers, not on the stack. |
| * See _x86boot_start() for this code. |
| */ |
| typedef void (*func_t)(int bist, int unused, ulong info) |
| __attribute__((regparm(3))); |
| |
| ((func_t)addr)(0, 0, info); |
| #else |
| cpu_call32(cs32, CONFIG_SYS_TEXT_BASE, info); |
| #endif |
| } |
| |
| #ifdef CONFIG_EFI_STUB_64BIT |
| static void get_gdt(struct desctab_info *info) |
| { |
| asm volatile ("sgdt %0" : : "m"(*info) : "memory"); |
| } |
| #endif |
| |
| static inline unsigned long read_cr3(void) |
| { |
| unsigned long val; |
| |
| asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory"); |
| return val; |
| } |
| |
| /** |
| * get_codeseg32() - Find the code segment to use for 32-bit code |
| * |
| * U-Boot only works in 32-bit mode at present, so when booting from 64-bit |
| * EFI we must first change to 32-bit mode. To do this we need to find the |
| * correct code segment to use (an entry in the Global Descriptor Table). |
| * |
| * @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found |
| */ |
| static int get_codeseg32(void) |
| { |
| int cs32 = 0; |
| |
| #ifdef CONFIG_EFI_STUB_64BIT |
| struct desctab_info gdt; |
| uint64_t *ptr; |
| int i; |
| |
| get_gdt(&gdt); |
| for (ptr = (uint64_t *)(unsigned long)gdt.addr, i = 0; i < gdt.limit; |
| i += 8, ptr++) { |
| uint64_t desc = *ptr; |
| uint64_t base, limit; |
| |
| /* |
| * Check that the target U-Boot jump address is within the |
| * selector and that the selector is of the right type. |
| */ |
| base = ((desc >> GDT_BASE_LOW_SHIFT) & GDT_BASE_LOW_MASK) | |
| ((desc >> GDT_BASE_HIGH_SHIFT) & GDT_BASE_HIGH_MASK) |
| << 16; |
| limit = ((desc >> GDT_LIMIT_LOW_SHIFT) & GDT_LIMIT_LOW_MASK) | |
| ((desc >> GDT_LIMIT_HIGH_SHIFT) & GDT_LIMIT_HIGH_MASK) |
| << 16; |
| base <<= 12; /* 4KB granularity */ |
| limit <<= 12; |
| if ((desc & GDT_PRESENT) && (desc & GDT_NOTSYS) && |
| !(desc & GDT_LONG) && (desc & GDT_4KB) && |
| (desc & GDT_32BIT) && (desc & GDT_CODE) && |
| CONFIG_SYS_TEXT_BASE > base && |
| CONFIG_SYS_TEXT_BASE + CONFIG_SYS_MONITOR_LEN < limit |
| ) { |
| cs32 = i; |
| break; |
| } |
| } |
| |
| #ifdef DEBUG |
| puts("\ngdt: "); |
| printhex8(gdt.limit); |
| puts(", addr: "); |
| printhex8(gdt.addr >> 32); |
| printhex8(gdt.addr); |
| for (i = 0; i < gdt.limit; i += 8) { |
| uint32_t *ptr = (uint32_t *)((unsigned long)gdt.addr + i); |
| |
| puts("\n"); |
| printhex2(i); |
| puts(": "); |
| printhex8(ptr[1]); |
| puts(" "); |
| printhex8(ptr[0]); |
| } |
| puts("\n "); |
| puts("32-bit code segment: "); |
| printhex2(cs32); |
| puts("\n "); |
| |
| puts("page_table: "); |
| printhex8(read_cr3()); |
| puts("\n "); |
| #endif |
| if (!cs32) { |
| puts("Can't find 32-bit code segment\n"); |
| return -ENOENT; |
| } |
| #endif |
| |
| return cs32; |
| } |
| |
| /** |
| * setup_info_table() - sets up a table containing information from EFI |
| * |
| * We must call exit_boot_services() before jumping out of the stub into U-Boot |
| * proper, so that U-Boot has full control of peripherals, memory, etc. |
| * |
| * Once we do this, we cannot call any boot-services functions so we must find |
| * out everything we need to before doing that. |
| * |
| * Set up a struct efi_info_hdr table which can hold various records (e.g. |
| * struct efi_entry_memmap) with information obtained from EFI. |
| * |
| * @priv: Pointer to our private information which contains the list |
| * @size: Size of the table to allocate |
| * Return: 0 if OK, non-zero on error |
| */ |
| static int setup_info_table(struct efi_priv *priv, int size) |
| { |
| struct efi_info_hdr *info; |
| efi_status_t ret; |
| |
| /* Get some memory for our info table */ |
| priv->info_size = size; |
| info = efi_malloc(priv, priv->info_size, &ret); |
| if (ret) { |
| printhex2(ret); |
| puts(" No memory for info table: "); |
| return ret; |
| } |
| |
| memset(info, '\0', sizeof(*info)); |
| info->version = EFI_TABLE_VERSION; |
| info->hdr_size = sizeof(*info); |
| priv->info = info; |
| priv->next_hdr = (char *)info + info->hdr_size; |
| |
| return 0; |
| } |
| |
| /** |
| * add_entry_addr() - Add a new entry to the efi_info list |
| * |
| * This adds an entry, consisting of a tag and two lots of data. This avoids the |
| * caller having to coalesce the data first |
| * |
| * @priv: Pointer to our private information which contains the list |
| * @type: Type of the entry to add |
| * @ptr1: Pointer to first data block to add |
| * @size1: Size of first data block in bytes (can be 0) |
| * @ptr2: Pointer to second data block to add |
| * @size2: Size of second data block in bytes (can be 0) |
| */ |
| static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type, |
| void *ptr1, int size1, void *ptr2, int size2) |
| { |
| struct efi_entry_hdr *hdr = priv->next_hdr; |
| |
| hdr->type = type; |
| hdr->size = size1 + size2; |
| hdr->addr = 0; |
| hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16); |
| priv->next_hdr += hdr->link; |
| memcpy(hdr + 1, ptr1, size1); |
| memcpy((void *)(hdr + 1) + size1, ptr2, size2); |
| priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info; |
| } |
| |
| /** |
| * efi_main() - Start an EFI image |
| * |
| * This function is called by our EFI start-up code. It handles running |
| * U-Boot. If it returns, EFI will continue. |
| */ |
| efi_status_t EFIAPI efi_main(efi_handle_t image, |
| struct efi_system_table *sys_table) |
| { |
| struct efi_priv local_priv, *priv = &local_priv; |
| struct efi_boot_services *boot = sys_table->boottime; |
| struct efi_mem_desc *desc; |
| struct efi_entry_memmap map; |
| struct efi_gop *gop; |
| struct efi_entry_gopmode mode; |
| struct efi_entry_systable table; |
| efi_guid_t efi_gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID; |
| efi_uintn_t key, desc_size, size; |
| efi_status_t ret; |
| u32 version; |
| int cs32; |
| |
| ret = efi_init(priv, "Payload", image, sys_table); |
| if (ret) { |
| printhex2(ret); |
| puts(" efi_init() failed\n"); |
| return ret; |
| } |
| efi_set_priv(priv); |
| |
| cs32 = get_codeseg32(); |
| if (cs32 < 0) |
| return EFI_UNSUPPORTED; |
| |
| /* Get the memory map so we can switch off EFI */ |
| size = 0; |
| ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version); |
| if (ret != EFI_BUFFER_TOO_SMALL) { |
| printhex2(EFI_BITS_PER_LONG); |
| putc(' '); |
| printhex2(ret); |
| puts(" No memory map\n"); |
| return ret; |
| } |
| size += 1024; /* Since doing a malloc() may change the memory map! */ |
| desc = efi_malloc(priv, size, &ret); |
| if (!desc) { |
| printhex2(ret); |
| puts(" No memory for memory descriptor\n"); |
| return ret; |
| } |
| ret = setup_info_table(priv, size + 128); |
| if (ret) |
| return ret; |
| |
| ret = boot->locate_protocol(&efi_gop_guid, NULL, (void **)&gop); |
| if (ret) { |
| puts(" GOP unavailable\n"); |
| } else { |
| mode.fb_base = gop->mode->fb_base; |
| mode.fb_size = gop->mode->fb_size; |
| mode.info_size = gop->mode->info_size; |
| add_entry_addr(priv, EFIET_GOP_MODE, &mode, sizeof(mode), |
| gop->mode->info, |
| sizeof(struct efi_gop_mode_info)); |
| } |
| |
| ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version); |
| if (ret) { |
| printhex2(ret); |
| puts(" Can't get memory map\n"); |
| return ret; |
| } |
| |
| table.sys_table = (ulong)sys_table; |
| add_entry_addr(priv, EFIET_SYS_TABLE, &table, sizeof(table), NULL, 0); |
| |
| ret = boot->exit_boot_services(image, key); |
| if (ret) { |
| /* |
| * Unfortunately it happens that we cannot exit boot services |
| * the first time. But the second time it work. I don't know |
| * why but this seems to be a repeatable problem. To get |
| * around it, just try again. |
| */ |
| printhex2(ret); |
| puts(" Can't exit boot services\n"); |
| size = sizeof(desc); |
| ret = boot->get_memory_map(&size, desc, &key, &desc_size, |
| &version); |
| if (ret) { |
| printhex2(ret); |
| puts(" Can't get memory map\n"); |
| return ret; |
| } |
| ret = boot->exit_boot_services(image, key); |
| if (ret) { |
| printhex2(ret); |
| puts(" Can't exit boot services 2\n"); |
| return ret; |
| } |
| } |
| |
| /* The EFI UART won't work now, switch to a debug one */ |
| use_uart = true; |
| |
| map.version = version; |
| map.desc_size = desc_size; |
| add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size); |
| add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0); |
| |
| memcpy((void *)CONFIG_SYS_TEXT_BASE, _binary_u_boot_bin_start, |
| (ulong)_binary_u_boot_bin_end - |
| (ulong)_binary_u_boot_bin_start); |
| |
| #ifdef DEBUG |
| puts("EFI table at "); |
| printhex8((ulong)priv->info); |
| puts(" size "); |
| printhex8(priv->info->total_size); |
| #endif |
| putc('\n'); |
| jump_to_uboot(cs32, CONFIG_SYS_TEXT_BASE, (ulong)priv->info); |
| |
| return EFI_LOAD_ERROR; |
| } |