1 files changed, 391 insertions, 0 deletions
diff --git a/roms/u-boot/lib/efi/efi_stub.c b/roms/u-boot/lib/efi/efi_stub.c
new file mode 100644
index 000000000..b3393e47f
--- /dev/null
+++ b/roms/u-boot/lib/efi/efi_stub.c
@@ -0,0 +1,391 @@
+// 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 struct efi_priv *global_priv;
+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)
+{
+	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(global_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;
+}
+
+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;
+}
+
+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;
+	}
+	global_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;
+}