It is useful to be able to load U-Boot onto a board even if is it already running EFI. This can allow access to the U-Boot command interface, flexible booting options and easier development. The easiest way to do this is to build U-Boot as a binary blob and have an EFI stub copy it into RAM. Add support for this feature, targeting 32-bit initially. Also add a way to detect when U-Boot has been loaded via a stub. This goes in common.h since it needs to be widely available so that we avoid redoing initialisation that should be skipped. Signed-off-by: Simon Glass <sjg@chromium.org> Improvements to how the payload is built: Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>master
Simon Glass
9 years ago
parent
465a67cf52
commit
476476e73b
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/*
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* Copyright (c) 2015 Google, Inc |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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* |
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* EFI information obtained here: |
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* http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES
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* |
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* Loads a payload (U-Boot) within the EFI environment. This is built as a |
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* 32-bit EFI application. |
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*/ |
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#include <common.h> |
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#include <debug_uart.h> |
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#include <efi.h> |
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#include <efi_api.h> |
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#include <errno.h> |
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#include <ns16550.h> |
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#include <asm/cpu.h> |
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#include <asm/io.h> |
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#include <linux/err.h> |
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#include <linux/types.h> |
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DECLARE_GLOBAL_DATA_PTR; |
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#ifndef CONFIG_X86 |
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/*
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* Problem areas: |
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* - putc() uses the ns16550 address directly and assumed I/O access. Many |
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* platforms will use memory access |
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* get_codeseg32() is only meaningful on x86 |
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*/ |
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#error "This file needs to be ported for use on architectures" |
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#endif |
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static struct efi_priv *global_priv; |
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static bool use_uart; |
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struct __packed desctab_info { |
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uint16_t limit; |
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uint64_t addr; |
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uint16_t pad; |
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}; |
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/*
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* EFI uses Unicode and we don't. The easiest way to get a sensible output |
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* function is to use the U-Boot debug UART. We use EFI's console output |
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* function where available, and assume the built-in UART after that. We rely |
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* on EFI to set up the UART for us and just bring in the functions here. |
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* This last bit is a bit icky, but it's only for debugging anyway. We could |
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* build in ns16550.c with some effort, but this is a payload loader after |
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* all. |
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* |
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* Note: We avoid using printf() so we don't need to bring in lib/vsprintf.c. |
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* That would require some refactoring since we already build this for U-Boot. |
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* Building an EFI shared library version would have to be a separate stem. |
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* That might push us to using the SPL framework to build this stub. However |
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* that would involve a round of EFI-specific changes in SPL. Worth |
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* considering if we start needing more U-Boot functionality. Note that we |
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* could then move get_codeseg32() to arch/x86/cpu/cpu.c. |
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*/ |
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void debug_uart_init(void) |
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{ |
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} |
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void putc(const char ch) |
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{ |
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if (use_uart) { |
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NS16550_t com_port = (NS16550_t)0x3f8; |
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while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0) |
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; |
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outb(ch, (ulong)&com_port->thr); |
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} else { |
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efi_putc(global_priv, ch); |
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} |
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if (ch == '\n') |
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putc('\r'); |
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} |
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void puts(const char *str) |
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{ |
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while (*str) |
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putc(*str++); |
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} |
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static void _debug_uart_putc(int ch) |
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{ |
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putc(ch); |
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} |
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DEBUG_UART_FUNCS |
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void *memcpy(void *dest, const void *src, size_t size) |
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{ |
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unsigned char *dptr = dest; |
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const unsigned char *ptr = src; |
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const unsigned char *end = src + size; |
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while (ptr < end) |
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*dptr++ = *ptr++; |
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return dest; |
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} |
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void *memset(void *inptr, int ch, size_t size) |
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{ |
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char *ptr = inptr; |
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char *end = ptr + size; |
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while (ptr < end) |
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*ptr++ = ch; |
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return ptr; |
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} |
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static void jump_to_uboot(ulong cs32, ulong addr, ulong info) |
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{ |
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#ifdef CONFIG_EFI_STUB_32BIT |
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/*
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* U-Boot requires these parameters in registers, not on the stack. |
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* See _x86boot_start() for this code. |
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*/ |
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typedef void (*func_t)(int bist, int unused, ulong info) |
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__attribute__((regparm(3))); |
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((func_t)addr)(0, 0, info); |
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#else |
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/* TODO: Implement this */ |
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#endif |
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} |
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static void get_gdt(struct desctab_info *info) |
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{ |
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asm volatile ("sgdt %0" : : "m"(*info) : "memory"); |
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} |
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static inline unsigned long read_cr3(void) |
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{ |
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unsigned long val; |
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asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory"); |
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return val; |
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} |
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/**
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* get_codeseg32() - Find the code segment to use for 32-bit code |
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* |
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* U-Boot only works in 32-bit mode at present, so when booting from 64-bit |
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* EFI we must first change to 32-bit mode. To do this we need to find the |
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* correct code segment to use (an entry in the Global Descriptor Table). |
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* |
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* @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found |
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*/ |
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static int get_codeseg32(void) |
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{ |
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int cs32 = 0; |
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/* TODO(sjg): Implement this for 64-bit mode */ |
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return cs32; |
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} |
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static int setup_info_table(struct efi_priv *priv, int size) |
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{ |
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struct efi_info_hdr *info; |
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efi_status_t ret; |
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/* Get some memory for our info table */ |
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priv->info_size = size; |
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info = efi_malloc(priv, priv->info_size, &ret); |
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if (ret) { |
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printhex2(ret); |
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puts(" No memory for info table: "); |
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return ret; |
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} |
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memset(info, '\0', sizeof(*info)); |
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info->version = EFI_TABLE_VERSION; |
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info->hdr_size = sizeof(*info); |
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priv->info = info; |
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priv->next_hdr = (char *)info + info->hdr_size; |
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return 0; |
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} |
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static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type, |
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void *ptr1, int size1, void *ptr2, int size2) |
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{ |
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struct efi_entry_hdr *hdr = priv->next_hdr; |
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hdr->type = type; |
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hdr->size = size1 + size2; |
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hdr->addr = 0; |
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hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16); |
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priv->next_hdr += hdr->link; |
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memcpy(hdr + 1, ptr1, size1); |
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memcpy((void *)(hdr + 1) + size1, ptr2, size2); |
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priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info; |
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} |
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/**
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* efi_main() - Start an EFI image |
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* |
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* This function is called by our EFI start-up code. It handles running |
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* U-Boot. If it returns, EFI will continue. |
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*/ |
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efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table) |
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{ |
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struct efi_priv local_priv, *priv = &local_priv; |
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struct efi_boot_services *boot = sys_table->boottime; |
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struct efi_mem_desc *desc; |
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struct efi_entry_memmap map; |
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ulong key, desc_size, size; |
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efi_status_t ret; |
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u32 version; |
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int cs32; |
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ret = efi_init(priv, "Payload", image, sys_table); |
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if (ret) { |
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printhex2(ret); puts(" efi_init() failed\n"); |
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return ret; |
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} |
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global_priv = priv; |
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cs32 = get_codeseg32(); |
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if (cs32 < 0) |
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return EFI_UNSUPPORTED; |
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/* Get the memory map so we can switch off EFI */ |
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size = 0; |
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ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version); |
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if (ret != EFI_BUFFER_TOO_SMALL) { |
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printhex2(BITS_PER_LONG); |
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printhex2(ret); |
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puts(" No memory map\n"); |
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return ret; |
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} |
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size += 1024; /* Since doing a malloc() may change the memory map! */ |
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desc = efi_malloc(priv, size, &ret); |
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if (!desc) { |
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printhex2(ret); |
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puts(" No memory for memory descriptor: "); |
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return ret; |
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} |
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ret = setup_info_table(priv, size + 128); |
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if (ret) |
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return ret; |
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ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version); |
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if (ret) { |
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printhex2(ret); |
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puts(" Can't get memory map\n"); |
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return ret; |
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} |
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ret = boot->exit_boot_services(image, key); |
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if (ret) { |
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/*
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* Unfortunately it happens that we cannot exit boot services |
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* the first time. But the second time it work. I don't know |
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* why but this seems to be a repeatable problem. To get |
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* around it, just try again. |
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*/ |
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printhex2(ret); |
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puts(" Can't exit boot services\n"); |
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size = sizeof(desc); |
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ret = boot->get_memory_map(&size, desc, &key, &desc_size, |
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&version); |
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if (ret) { |
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printhex2(ret); |
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puts(" Can't get memory map\n"); |
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return ret; |
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} |
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ret = boot->exit_boot_services(image, key); |
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if (ret) { |
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printhex2(ret); |
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puts(" Can't exit boot services 2\n"); |
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return ret; |
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} |
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} |
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map.version = version; |
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map.desc_size = desc_size; |
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add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size); |
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add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0); |
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/* The EFI UART won't work now, switch to a debug one */ |
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use_uart = true; |
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memcpy((void *)CONFIG_SYS_TEXT_BASE, _binary_u_boot_dtb_bin_start, |
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(ulong)_binary_u_boot_dtb_bin_end - |
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(ulong)_binary_u_boot_dtb_bin_start); |
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#ifdef DEBUG |
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puts("EFI table at "); |
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printhex8((ulong)priv->info); |
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puts(" size "); |
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printhex8(priv->info->total_size); |
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#endif |
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putc('\n'); |
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jump_to_uboot(cs32, CONFIG_SYS_TEXT_BASE, (ulong)priv->info); |
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return EFI_LOAD_ERROR; |
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} |
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Reference in new issue