[deliverable/linux.git] / drivers / firmware / efi / arm-stub.c

/*
 * EFI stub implementation that is shared by arm and arm64 architectures.
 * This should be #included by the EFI stub implementation files.
 *
 * Copyright (C) 2013,2014 Linaro Limited
 *     Roy Franz <roy.franz@linaro.org
 * Copyright (C) 2013 Red Hat, Inc.
 *     Mark Salter <msalter@redhat.com>
 *
 * This file is part of the Linux kernel, and is made available under the
 * terms of the GNU General Public License version 2.
 *
 */

#include <linux/efi.h>
#include <asm/efi.h>

#include "efistub.h"

static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
	static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
	static efi_char16_t const var_name[] __initconst = {
		'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };

	efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
	unsigned long size = sizeof(u8);
	efi_status_t status;
	u8 val;

	status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid,
			  NULL, &size, &val);

	switch (status) {
	case EFI_SUCCESS:
		return val;
	case EFI_NOT_FOUND:
		return 0;
	default:
		return 1;
	}
}

efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
			     void *__image, void **__fh)
{
	efi_file_io_interface_t *io;
	efi_loaded_image_t *image = __image;
	efi_file_handle_t *fh;
	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
	efi_status_t status;
	void *handle = (void *)(unsigned long)image->device_handle;

	status = sys_table_arg->boottime->handle_protocol(handle,
				 &fs_proto, (void **)&io);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
		return status;
	}

	status = io->open_volume(io, &fh);
	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to open volume\n");

	*__fh = fh;
	return status;
}

efi_status_t efi_file_close(void *handle)
{
	efi_file_handle_t *fh = handle;

	return fh->close(handle);
}

efi_status_t
efi_file_read(void *handle, unsigned long *size, void *addr)
{
	efi_file_handle_t *fh = handle;

	return fh->read(handle, size, addr);
}


efi_status_t
efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
	      efi_char16_t *filename_16, void **handle, u64 *file_sz)
{
	efi_file_handle_t *h, *fh = __fh;
	efi_file_info_t *info;
	efi_status_t status;
	efi_guid_t info_guid = EFI_FILE_INFO_ID;
	unsigned long info_sz;

	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to open file: ");
		efi_char16_printk(sys_table_arg, filename_16);
		efi_printk(sys_table_arg, "\n");
		return status;
	}

	*handle = h;

	info_sz = 0;
	status = h->get_info(h, &info_guid, &info_sz, NULL);
	if (status != EFI_BUFFER_TOO_SMALL) {
		efi_printk(sys_table_arg, "Failed to get file info size\n");
		return status;
	}

grow:
	status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
				 info_sz, (void **)&info);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
		return status;
	}

	status = h->get_info(h, &info_guid, &info_sz,
						   info);
	if (status == EFI_BUFFER_TOO_SMALL) {
		sys_table_arg->boottime->free_pool(info);
		goto grow;
	}

	*file_sz = info->file_size;
	sys_table_arg->boottime->free_pool(info);

	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to get initrd info\n");

	return status;
}


void efi_char16_printk(efi_system_table_t *sys_table_arg,
			      efi_char16_t *str)
{
	struct efi_simple_text_output_protocol *out;

	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	out->output_string(out, str);
}


/*
 * This function handles the architcture specific differences between arm and
 * arm64 regarding where the kernel image must be loaded and any memory that
 * must be reserved. On failure it is required to free all
 * all allocations it has made.
 */
efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
				 unsigned long *image_addr,
				 unsigned long *image_size,
				 unsigned long *reserve_addr,
				 unsigned long *reserve_size,
				 unsigned long dram_base,
				 efi_loaded_image_t *image);
/*
 * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
 * that is described in the PE/COFF header.  Most of the code is the same
 * for both archictectures, with the arch-specific code provided in the
 * handle_kernel_image() function.
 */
unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table,
			       unsigned long *image_addr)
{
	efi_loaded_image_t *image;
	efi_status_t status;
	unsigned long image_size = 0;
	unsigned long dram_base;
	/* addr/point and size pairs for memory management*/
	unsigned long initrd_addr;
	u64 initrd_size = 0;
	unsigned long fdt_addr = 0;  /* Original DTB */
	u64 fdt_size = 0;  /* We don't get size from configuration table */
	char *cmdline_ptr = NULL;
	int cmdline_size = 0;
	unsigned long new_fdt_addr;
	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	unsigned long reserve_addr = 0;
	unsigned long reserve_size = 0;

	/* Check if we were booted by the EFI firmware */
	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		goto fail;

	pr_efi(sys_table, "Booting Linux Kernel...\n");

	/*
	 * Get a handle to the loaded image protocol.  This is used to get
	 * information about the running image, such as size and the command
	 * line.
	 */
	status = sys_table->boottime->handle_protocol(handle,
					&loaded_image_proto, (void *)&image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
		goto fail;
	}

	dram_base = get_dram_base(sys_table);
	if (dram_base == EFI_ERROR) {
		pr_efi_err(sys_table, "Failed to find DRAM base\n");
		goto fail;
	}
	status = handle_kernel_image(sys_table, image_addr, &image_size,
				     &reserve_addr,
				     &reserve_size,
				     dram_base, image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to relocate kernel\n");
		goto fail;
	}

	/*
	 * Get the command line from EFI, using the LOADED_IMAGE
	 * protocol. We are going to copy the command line into the
	 * device tree, so this can be allocated anywhere.
	 */
	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	if (!cmdline_ptr) {
		pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
		goto fail_free_image;
	}

	/*
	 * Unauthenticated device tree data is a security hazard, so
	 * ignore 'dtb=' unless UEFI Secure Boot is disabled.
	 */
	if (efi_secureboot_enabled(sys_table)) {
		pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
	} else {
		status = handle_cmdline_files(sys_table, image, cmdline_ptr,
					      "dtb=",
					      ~0UL, (unsigned long *)&fdt_addr,
					      (unsigned long *)&fdt_size);

		if (status != EFI_SUCCESS) {
			pr_efi_err(sys_table, "Failed to load device tree!\n");
			goto fail_free_cmdline;
		}
	}
	if (!fdt_addr)
		/* Look for a device tree configuration table entry. */
		fdt_addr = (uintptr_t)get_fdt(sys_table);

	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
				      "initrd=", dram_base + SZ_512M,
				      (unsigned long *)&initrd_addr,
				      (unsigned long *)&initrd_size);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table, "Failed initrd from command line!\n");

	new_fdt_addr = fdt_addr;
	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
				&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
				initrd_addr, initrd_size, cmdline_ptr,
				fdt_addr, fdt_size);

	/*
	 * If all went well, we need to return the FDT address to the
	 * calling function so it can be passed to kernel as part of
	 * the kernel boot protocol.
	 */
	if (status == EFI_SUCCESS)
		return new_fdt_addr;

	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");

	efi_free(sys_table, initrd_size, initrd_addr);
	efi_free(sys_table, fdt_size, fdt_addr);

fail_free_cmdline:
	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);

fail_free_image:
	efi_free(sys_table, image_size, *image_addr);
	efi_free(sys_table, reserve_size, reserve_addr);
fail:
	return EFI_ERROR;
}
Commit	Line	Data
3c7f2550 MS	1	/*
	2	* EFI stub implementation that is shared by arm and arm64 architectures.
	3	* This should be #included by the EFI stub implementation files.
	4	*
	5	* Copyright (C) 2013,2014 Linaro Limited
	6	* Roy Franz <roy.franz@linaro.org
	7	* Copyright (C) 2013 Red Hat, Inc.
	8	* Mark Salter <msalter@redhat.com>
	9	*
	10	* This file is part of the Linux kernel, and is made available under the
	11	* terms of the GNU General Public License version 2.
	12	*
	13	*/
	14
bd669475 AB	15	#include <linux/efi.h>
	16	#include <asm/efi.h>
	17
	18	#include "efistub.h"
	19
345c736e AB	20	static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
	21	{
	22	static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
	23	static efi_char16_t const var_name[] __initconst = {
	24	'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
	25
	26	efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
	27	unsigned long size = sizeof(u8);
	28	efi_status_t status;
	29	u8 val;
	30
	31	status = f_getvar((efi_char16_t )var_name, (efi_guid_t )&var_guid,
	32	NULL, &size, &val);
	33
	34	switch (status) {
	35	case EFI_SUCCESS:
	36	return val;
	37	case EFI_NOT_FOUND:
	38	return 0;
	39	default:
	40	return 1;
	41	}
	42	}
	43
bd669475 AB	44	efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
bd669475 AB	45	void __image, void *__fh)
3c7f2550 MS	46	{
	47	efi_file_io_interface_t *io;
	48	efi_loaded_image_t *image = __image;
	49	efi_file_handle_t *fh;
	50	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
	51	efi_status_t status;
	52	void handle = (void )(unsigned long)image->device_handle;
	53
	54	status = sys_table_arg->boottime->handle_protocol(handle,
	55	&fs_proto, (void **)&io);
	56	if (status != EFI_SUCCESS) {
	57	efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
	58	return status;
	59	}
	60
	61	status = io->open_volume(io, &fh);
	62	if (status != EFI_SUCCESS)
	63	efi_printk(sys_table_arg, "Failed to open volume\n");
	64
	65	*__fh = fh;
	66	return status;
	67	}
bd669475 AB	68
bd669475 AB	69	efi_status_t efi_file_close(void *handle)
3c7f2550 MS	70	{
	71	efi_file_handle_t *fh = handle;
	72
	73	return fh->close(handle);
	74	}
	75
bd669475	76	efi_status_t
3c7f2550 MS	77	efi_file_read(void handle, unsigned long size, void *addr)
	78	{
	79	efi_file_handle_t *fh = handle;
	80
	81	return fh->read(handle, size, addr);
	82	}
	83
	84
bd669475	85	efi_status_t
3c7f2550 MS	86	efi_file_size(efi_system_table_t sys_table_arg, void __fh,
	87	efi_char16_t filename_16, void handle, u64 file_sz)
	88	{
	89	efi_file_handle_t h, fh = __fh;
	90	efi_file_info_t *info;
	91	efi_status_t status;
	92	efi_guid_t info_guid = EFI_FILE_INFO_ID;
	93	unsigned long info_sz;
	94
	95	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
	96	if (status != EFI_SUCCESS) {
	97	efi_printk(sys_table_arg, "Failed to open file: ");
	98	efi_char16_printk(sys_table_arg, filename_16);
	99	efi_printk(sys_table_arg, "\n");
	100	return status;
	101	}
	102
	103	*handle = h;
	104
	105	info_sz = 0;
	106	status = h->get_info(h, &info_guid, &info_sz, NULL);
	107	if (status != EFI_BUFFER_TOO_SMALL) {
	108	efi_printk(sys_table_arg, "Failed to get file info size\n");
	109	return status;
	110	}
	111
	112	grow:
	113	status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
	114	info_sz, (void **)&info);
	115	if (status != EFI_SUCCESS) {
	116	efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
	117	return status;
	118	}
	119
	120	status = h->get_info(h, &info_guid, &info_sz,
	121	info);
	122	if (status == EFI_BUFFER_TOO_SMALL) {
	123	sys_table_arg->boottime->free_pool(info);
	124	goto grow;
	125	}
	126
	127	*file_sz = info->file_size;
	128	sys_table_arg->boottime->free_pool(info);
	129
	130	if (status != EFI_SUCCESS)
	131	efi_printk(sys_table_arg, "Failed to get initrd info\n");
	132
	133	return status;
	134	}
	135
	136
	137
bd669475	138	void efi_char16_printk(efi_system_table_t *sys_table_arg,
3c7f2550 MS	139	efi_char16_t *str)
	140	{
	141	struct efi_simple_text_output_protocol *out;
	142
	143	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	144	out->output_string(out, str);
	145	}
	146
	147
	148	/*
	149	* This function handles the architcture specific differences between arm and
	150	* arm64 regarding where the kernel image must be loaded and any memory that
	151	* must be reserved. On failure it is required to free all
	152	* all allocations it has made.
	153	*/
bd669475 AB	154	efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
	155	unsigned long *image_addr,
	156	unsigned long *image_size,
	157	unsigned long *reserve_addr,
	158	unsigned long *reserve_size,
	159	unsigned long dram_base,
	160	efi_loaded_image_t *image);
3c7f2550 MS	161	/*
	162	* EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
	163	* that is described in the PE/COFF header. Most of the code is the same
	164	* for both archictectures, with the arch-specific code provided in the
	165	* handle_kernel_image() function.
	166	*/
	167	unsigned long __init efi_entry(void handle, efi_system_table_t sys_table,
	168	unsigned long *image_addr)
	169	{
	170	efi_loaded_image_t *image;
	171	efi_status_t status;
	172	unsigned long image_size = 0;
	173	unsigned long dram_base;
	174	/* addr/point and size pairs for memory management*/
	175	unsigned long initrd_addr;
	176	u64 initrd_size = 0;
345c736e	177	unsigned long fdt_addr = 0; /* Original DTB */
3c7f2550 MS	178	u64 fdt_size = 0; /* We don't get size from configuration table */
	179	char *cmdline_ptr = NULL;
	180	int cmdline_size = 0;
	181	unsigned long new_fdt_addr;
	182	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	183	unsigned long reserve_addr = 0;
	184	unsigned long reserve_size = 0;
	185
	186	/* Check if we were booted by the EFI firmware */
	187	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
	188	goto fail;
	189
	190	pr_efi(sys_table, "Booting Linux Kernel...\n");
	191
	192	/*
	193	* Get a handle to the loaded image protocol. This is used to get
	194	* information about the running image, such as size and the command
	195	* line.
	196	*/
	197	status = sys_table->boottime->handle_protocol(handle,
	198	&loaded_image_proto, (void *)&image);
	199	if (status != EFI_SUCCESS) {
	200	pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
	201	goto fail;
	202	}
	203
	204	dram_base = get_dram_base(sys_table);
	205	if (dram_base == EFI_ERROR) {
	206	pr_efi_err(sys_table, "Failed to find DRAM base\n");
	207	goto fail;
	208	}
	209	status = handle_kernel_image(sys_table, image_addr, &image_size,
	210	&reserve_addr,
	211	&reserve_size,
	212	dram_base, image);
	213	if (status != EFI_SUCCESS) {
	214	pr_efi_err(sys_table, "Failed to relocate kernel\n");
	215	goto fail;
	216	}
	217
	218	/*
	219	* Get the command line from EFI, using the LOADED_IMAGE
	220	* protocol. We are going to copy the command line into the
	221	* device tree, so this can be allocated anywhere.
	222	*/
	223	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	224	if (!cmdline_ptr) {
	225	pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
	226	goto fail_free_image;
	227	}
	228
345c736e AB	229	/*
	230	* Unauthenticated device tree data is a security hazard, so
	231	* ignore 'dtb=' unless UEFI Secure Boot is disabled.
	232	*/
	233	if (efi_secureboot_enabled(sys_table)) {
	234	pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
	235	} else {
3c7f2550 MS	236	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
	237	"dtb=",
	238	~0UL, (unsigned long *)&fdt_addr,
	239	(unsigned long *)&fdt_size);
	240
	241	if (status != EFI_SUCCESS) {
	242	pr_efi_err(sys_table, "Failed to load device tree!\n");
	243	goto fail_free_cmdline;
	244	}
	245	}
345c736e AB	246	if (!fdt_addr)
	247	/* Look for a device tree configuration table entry. */
	248	fdt_addr = (uintptr_t)get_fdt(sys_table);
3c7f2550 MS	249
	250	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
	251	"initrd=", dram_base + SZ_512M,
	252	(unsigned long *)&initrd_addr,
	253	(unsigned long *)&initrd_size);
	254	if (status != EFI_SUCCESS)
	255	pr_efi_err(sys_table, "Failed initrd from command line!\n");
	256
	257	new_fdt_addr = fdt_addr;
	258	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
	259	&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
	260	initrd_addr, initrd_size, cmdline_ptr,
	261	fdt_addr, fdt_size);
	262
	263	/*
	264	* If all went well, we need to return the FDT address to the
	265	* calling function so it can be passed to kernel as part of
	266	* the kernel boot protocol.
	267	*/
	268	if (status == EFI_SUCCESS)
	269	return new_fdt_addr;
	270
	271	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
	272
	273	efi_free(sys_table, initrd_size, initrd_addr);
	274	efi_free(sys_table, fdt_size, fdt_addr);
	275
	276	fail_free_cmdline:
	277	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
	278
	279	fail_free_image:
	280	efi_free(sys_table, image_size, *image_addr);
	281	efi_free(sys_table, reserve_size, reserve_addr);
	282	fail:
	283	return EFI_ERROR;
	284	}