This implements a filesystem for accessing EFI variables. It is compatible to the Linux Kernel efivarfs filesystem. Currently the variables can only be accessed readonly.
Signed-off-by: Sascha Hauer <[email protected]> --- fs/Kconfig | 7 ++ fs/Makefile | 1 + fs/efivarfs.c | 340 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 348 insertions(+) create mode 100644 fs/efivarfs.c diff --git a/fs/Kconfig b/fs/Kconfig index 21690de..64fc117 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -49,6 +49,13 @@ config FS_EFI This filesystem driver provides access to the filesystems provided by the EFI Firmware via the EFI Simple File System Protocol. +config FS_EFIVARFS + depends on ARCH_EFI + bool + prompt "EFI variable filesystem support (efivarfs)" + help + This filesystem driver provides access to EFI variables. + source fs/fat/Kconfig source fs/ubifs/Kconfig diff --git a/fs/Makefile b/fs/Makefile index f027851..f5aae91 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_FS_NFS) += nfs.o parseopt.o obj-$(CONFIG_FS_BPKFS) += bpkfs.o obj-$(CONFIG_FS_UIMAGEFS) += uimagefs.o obj-$(CONFIG_FS_EFI) += efi.o +obj-$(CONFIG_FS_EFIVARFS) += efivarfs.o diff --git a/fs/efivarfs.c b/fs/efivarfs.c new file mode 100644 index 0000000..58c637e --- /dev/null +++ b/fs/efivarfs.c @@ -0,0 +1,340 @@ +/* + * ramfs.c - a malloc based filesystem + * + * Copyright (c) 2007 Sascha Hauer <[email protected]>, Pengutronix + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <common.h> +#include <driver.h> +#include <init.h> +#include <malloc.h> +#include <fs.h> +#include <string.h> +#include <errno.h> +#include <linux/stat.h> +#include <xfuncs.h> +#include <fcntl.h> +#include <efi.h> +#include <wchar.h> +#include <linux/err.h> +#include <linux/ctype.h> +#include <mach/efi.h> +#include <mach/efi-device.h> + +struct efivarfs_priv { + struct efi_file_handle *root_dir; + struct efi_file_io_interface *protocol; +}; + +static int char_to_nibble(char c) +{ + int ret = tolower(c); + + return ret <= '9' ? ret - '0' : ret - 'a' + 10; +} + +static int read_byte_str(const char *str, u8 *out) +{ + if (!isxdigit(*str) || !isxdigit(*(str + 1))) + return -EINVAL; + + *out = (char_to_nibble(*str) << 4) | char_to_nibble(*(str + 1)); + + return 0; +} + +int efi_guid_parse(const char *str, efi_guid_t *guid) +{ + int i, ret; + u8 idx[] = { 3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11, 12, 13, 14, 15 }; + + for (i = 0; i < 16; i++) { + ret = read_byte_str(str, &guid->b[idx[i]]); + if (ret) + return ret; + str += 2; + + switch (i) { + case 3: + case 5: + case 7: + case 9: + if (*str != '-') + return -EINVAL; + str++; + break; + } + } + + return 0; +} + +static int efivarfs_parse_filename(const char *filename, efi_guid_t *vendor, s16 **name) +{ + int len, ret; + const char *guidstr; + s16 *varname; + int i; + + if (*filename == '/') + filename++; + + len = strlen(filename); + + if (len < sizeof("-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")) + return -EINVAL; + + guidstr = filename + len - sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"); + if (*guidstr != '-') + return -EINVAL; + + guidstr++; + + ret = efi_guid_parse(guidstr, vendor); + + varname = xzalloc((guidstr - filename) * sizeof(s16)); + + for (i = 0; i < guidstr - filename - 1; i++) + varname[i] = filename[i]; + + *name = varname; + + return 0; +} + +struct efivars_file { + void *buf; + unsigned long size; + efi_guid_t vendor; + s16 *name; +}; + +static int efivarfs_open(struct device_d *dev, FILE *f, const char *filename) +{ + struct efivars_file *efile; + efi_status_t efiret; + int ret; + uint32_t attributes; + + efile = xzalloc(sizeof(*efile)); + + ret = efivarfs_parse_filename(filename, &efile->vendor, &efile->name); + if (ret) + return -ENOENT; + + efiret = RT->get_variable(efile->name, &efile->vendor, &attributes, &efile->size, NULL); + if (EFI_ERROR(efiret) && efiret != EFI_BUFFER_TOO_SMALL) { + ret = -efi_errno(efiret); + goto out; + } + + efile->buf = malloc(efile->size + sizeof(uint32_t)); + if (!efile->buf) { + ret = -ENOMEM; + goto out; + } + + efiret = RT->get_variable(efile->name, &efile->vendor, NULL, &efile->size, + efile->buf + sizeof(uint32_t)); + if (EFI_ERROR(efiret)) { + ret = -efi_errno(efiret); + goto out; + } + + *(uint32_t *)efile->buf = attributes; + + f->size = efile->size + sizeof(uint32_t); + f->inode = efile; + + return 0; + +out: + free(efile->buf); + free(efile); + + return ret; +} + +static int efivarfs_close(struct device_d *dev, FILE *f) +{ + struct efivars_file *efile = f->inode; + + free(efile->buf); + free(efile); + + return 0; +} + +static int efivarfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize) +{ + struct efivars_file *efile = f->inode; + + memcpy(buf, efile->buf + f->pos, insize); + + return insize; +} + +static loff_t efivarfs_lseek(struct device_d *dev, FILE *f, loff_t pos) +{ + f->pos = pos; + + return f->pos; +} + +struct efivarfs_dir_entry { + char *name; + struct efivarfs_dir_entry *next; +}; + +struct efivarfs_dir { + struct efivarfs_dir_entry *first; + struct efivarfs_dir_entry *current; + DIR dir; +}; + +static DIR *efivarfs_opendir(struct device_d *dev, const char *pathname) +{ + efi_status_t efiret; + efi_guid_t vendor; + s16 name[1024]; + struct efivarfs_dir *edir; + unsigned long size; + unsigned char *name8; + + name[0] = 0; + + edir = xzalloc(sizeof(*edir)); + + while (1) { + struct efivarfs_dir_entry *entry; + + size = sizeof(name); + efiret = RT->get_next_variable(&size, name, &vendor); + if (EFI_ERROR(efiret)) + break; + + entry = xzalloc(sizeof(*entry)); + name8 = strdup_wchar_to_char(name); + + entry->name = asprintf("%s-%pUl", name8, &vendor); + + free(name8); + + if (!edir->first) + edir->first = entry; + + if (edir->current) + edir->current->next = entry; + + edir->current = entry; + } + + edir->current = edir->first; + + return &edir->dir; +} + +static struct dirent *efivarfs_readdir(struct device_d *dev, DIR *dir) +{ + struct efivarfs_dir *edir = container_of(dir, struct efivarfs_dir, dir); + + if (!edir->current) + return NULL; + + strcpy(dir->d.d_name, edir->current->name); + + edir->current = edir->current->next; + + return &dir->d; +} + +static int efivarfs_closedir(struct device_d *dev, DIR *dir) +{ + struct efivarfs_dir *edir = container_of(dir, struct efivarfs_dir, dir); + struct efivarfs_dir_entry *entry; + + entry = edir->first; + + while (entry) { + struct efivarfs_dir_entry *tmp; + free(entry->name); + tmp = entry->next; + free(entry); + entry = tmp; + } + + free(edir); + + return 0; +} + +static int efivarfs_stat(struct device_d *dev, const char *filename, struct stat *s) +{ + efi_guid_t vendor; + s16 *name; + efi_status_t efiret; + unsigned long size = 0; + int ret; + + ret = efivarfs_parse_filename(filename, &vendor, &name); + if (ret) + return -ENOENT; + + efiret = RT->get_variable(name, &vendor, NULL, &size, NULL); + + free(name); + + if (EFI_ERROR(efiret) && efiret != EFI_BUFFER_TOO_SMALL) + return -efi_errno(efiret); + + s->st_mode = 00666 | S_IFREG; + s->st_size = size; + + return 0; +} + +static int efivarfs_probe(struct device_d *dev) +{ + return 0; +} + +static void efivarfs_remove(struct device_d *dev) +{ + free(dev->priv); +} + +static struct fs_driver_d efivarfs_driver = { + .open = efivarfs_open, + .close = efivarfs_close, + .read = efivarfs_read, + .lseek = efivarfs_lseek, + .opendir = efivarfs_opendir, + .readdir = efivarfs_readdir, + .closedir = efivarfs_closedir, + .stat = efivarfs_stat, + .drv = { + .probe = efivarfs_probe, + .remove = efivarfs_remove, + .name = "efivarfs", + } +}; + +static int efivarfs_init(void) +{ + return register_fs_driver(&efivarfs_driver); +} + +coredevice_initcall(efivarfs_init); -- 2.0.0 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
