1 /* SPDX-License-Identifier: GPL-2.0+ BSD-3-Clause */
3 * This provides a standard way of passing information between boot phases
4 * (TPL -> SPL -> U-Boot proper.)
6 * It consists of a list of blobs of data, tagged with their owner / contents.
7 * The list resides in memory and can be updated by SPL, U-Boot, etc.
9 * Design goals for bloblist:
11 * 1. Small and efficient structure. This avoids UUIDs or 16-byte name fields,
12 * since a 32-bit tag provides enough space for all the tags we will even need.
13 * If UUIDs are desired, they can be added inside a particular blob.
15 * 2. Avoids use of pointers, so the structure can be relocated in memory. The
16 * data in each blob is inline, rather than using pointers.
18 * 3. Bloblist is designed to start small in TPL or SPL, when only a few things
19 * are needed, like the memory size or whether console output should be enabled.
20 * Then it can grow in U-Boot proper, e.g. to include space for ACPI tables.
22 * 4. The bloblist structure is simple enough that it can be implemented in a
23 * small amount of C code. The API does not require use of strings or UUIDs,
24 * which would add to code size. For Thumb-2 the code size needed in SPL is
25 * approximately 940 bytes (e.g. for chromebook_bob).
27 * 5. Bloblist uses 16-byte alignment internally and is designed to start on a
28 * 16-byte boundary. Its headers are multiples of 16 bytes. This makes it easier
29 * to deal with data structures which need this level of alignment, such as ACPI
30 * tables. For use in SPL and TPL the alignment can be relaxed, since it can be
31 * relocated to an aligned address in U-Boot proper.
33 * 6. Bloblist is designed to be passed to Linux as reserved memory. While linux
34 * doesn't understand the bloblist header, it can be passed the indivdual blobs.
35 * For example, ACPI tables can reside in a blob and the address of those is
36 * passed to Linux, without Linux ever being away of the existence of a
37 * bloblist. Having all the blobs contiguous in memory simplifies the
38 * reserved-memory space.
40 * 7. Bloblist tags are defined in the enum below. There is an area for
41 * project-specific stuff (e.g. U-Boot, TF-A) and vendor-specific stuff, e.g.
42 * something used only on a particular SoC. There is also a private area for
43 * temporary, local use.
45 * 8. Bloblist includes a simple checksum, so that each boot phase can update
46 * this and allow the next phase to check that all is well. While the bloblist
47 * is small, this is quite cheap to calculate. When it grows (e.g. in U-Boot\
48 * proper), the CPU is likely running faster, so it is not prohibitive. Having
49 * said that, U-Boot is often the last phase that uses bloblist, so calculating
50 * the checksum there may not be necessary.
52 * 9. It would be possible to extend bloblist to support a non-contiguous
53 * structure, e.g. by creating a blob type that points to the next bloblist.
54 * This does not seem necessary for now. It adds complexity and code. We can
55 * always just copy it.
57 * 10. Bloblist is designed for simple structures, those that can be defined by
58 * a single C struct. More complex structures should be passed in a device tree.
59 * There are some exceptions, chiefly the various binary structures that Intel
60 * is fond of creating. But device tree provides a dictionary-type format which
61 * is fairly efficient (for use in U-Boot proper and Linux at least), along with
62 * a schema and a good set of tools. New formats should be designed around
63 * device tree rather than creating new binary formats, unless they are needed
64 * early in boot (where libfdt's 3KB of overhead is too large) and are trival
65 * enough to be described by a C struct.
67 * Copyright 2018 Google, Inc
68 * Written by Simon Glass <sjg@chromium.org>
78 BLOBLIST_MAGIC = 0xb00757a3,
82 /* Supported tags - add new ones to tag_name in bloblist.c */
87 * Standard area to allocate blobs used across firmware components, for
88 * things that are very commonly used, particularly in multiple
91 BLOBLISTT_AREA_FIRMWARE_TOP = 0x1,
93 /* Standard area to allocate blobs used across firmware components */
94 BLOBLISTT_AREA_FIRMWARE = 0x100,
96 * Advanced Configuration and Power Interface Global Non-Volatile
97 * Sleeping table. This forms part of the ACPI tables passed to Linux.
99 BLOBLISTT_ACPI_GNVS = 0x100,
100 BLOBLISTT_INTEL_VBT = 0x101, /* Intel Video-BIOS table */
101 BLOBLISTT_TPM2_TCG_LOG = 0x102, /* TPM v2 log space */
102 BLOBLISTT_TCPA_LOG = 0x103, /* TPM log space */
103 BLOBLISTT_ACPI_TABLES = 0x104, /* ACPI tables for x86 */
104 BLOBLISTT_SMBIOS_TABLES = 0x105, /* SMBIOS tables for x86 */
105 BLOBLISTT_VBOOT_CTX = 0x106, /* Chromium OS verified boot context */
108 * Project-specific tags are permitted here. Projects can be open source
109 * or not, but the format of the data must be fuily documented in an
110 * open source project, including all fields, bits, etc. Naming should
111 * be: BLOBLISTT_<project>_<purpose_here>
113 BLOBLISTT_PROJECT_AREA = 0x8000,
114 BLOBLISTT_U_BOOT_SPL_HANDOFF = 0x8000, /* Hand-off info from SPL */
117 * Vendor-specific tags are permitted here. Projects can be open source
118 * or not, but the format of the data must be fuily documented in an
119 * open source project, including all fields, bits, etc. Naming should
120 * be BLOBLISTT_<vendor>_<purpose_here>
122 BLOBLISTT_VENDOR_AREA = 0xc000,
124 /* Tags after this are not allocated for now */
125 BLOBLISTT_EXPANSION = 0x10000,
128 * Tags from here are on reserved for private use within a single
129 * firmware binary (i.e. a single executable or phase of a project).
130 * These tags can be passed between binaries within a local
131 * implementation, but cannot be used in upstream code. Allocate a
132 * tag in one of the areas above if you want that.
134 * This area may move in future.
136 BLOBLISTT_PRIVATE_AREA = 0xffff0000,
140 * struct bloblist_hdr - header for the bloblist
142 * This is stored at the start of the bloblist which is always on a 16-byte
143 * boundary. Records follow this header. The bloblist normally stays in the
144 * same place in memory as SPL and U-Boot execute, but it can be safely moved
147 * None of the bloblist headers themselves contain pointers but it is possible
148 * to put pointers inside a bloblist record if desired. This is not encouraged,
149 * since it can make part of the bloblist inaccessible if the pointer is
150 * no-longer valid. It is better to just store all the data inside a bloblist
153 * Each bloblist record is aligned to a 16-byte boundary and follows immediately
156 * @magic: BLOBLIST_MAGIC
157 * @version: BLOBLIST_VERSION
158 * @hdr_size: Size of this header, normally sizeof(struct bloblist_hdr). The
159 * first bloblist_rec starts at this offset from the start of the header
160 * @flags: Space for BLOBLISTF... flags (none yet)
161 * @size: Total size of the bloblist (non-zero if valid) including this header.
162 * The bloblist extends for this many bytes from the start of this header.
163 * When adding new records, the bloblist can grow up to this size.
164 * @alloced: Total size allocated so far for this bloblist. This starts out as
165 * sizeof(bloblist_hdr) since we need at least that much space to store a
167 * @spare: Spare space (for future use)
168 * @chksum: CRC32 for the entire bloblist allocated area. Since any of the
169 * blobs can be altered after being created, this checksum is only valid
170 * when the bloblist is finalised before jumping to the next stage of boot.
171 * Note that chksum is last to make it easier to exclude it from the
172 * checksum calculation.
174 struct bloblist_hdr {
187 * struct bloblist_rec - record for the bloblist
189 * The bloblist contains a number of records each consisting of this record
190 * structure followed by the data contained. Each records is 16-byte aligned.
192 * NOTE: Only exported for testing purposes. Do not use this struct.
194 * @tag: Tag indicating what the record contains
195 * @hdr_size: Size of this header, normally sizeof(struct bloblist_rec). The
196 * record's data starts at this offset from the start of the record
197 * @size: Size of record in bytes, excluding the header size. This does not
198 * need to be aligned (e.g. 3 is OK).
199 * @spare: Spare space for other things
201 struct bloblist_rec {
209 * bloblist_check_magic() - return a bloblist if the magic matches
211 * @addr: Address to check
212 * Return: pointer to bloblist, if the magic matches, else NULL
214 static inline void *bloblist_check_magic(ulong addr)
220 ptr = map_sysmem(addr, 0);
221 if (*ptr != BLOBLIST_MAGIC)
228 * bloblist_find() - Find a blob
230 * Searches the bloblist and returns the blob with the matching tag
232 * @tag: Tag to search for (enum bloblist_tag_t)
233 * @size: Expected size of the blob, or 0 for any size
234 * Return: pointer to blob if found, or NULL if not found, or a blob was found
235 * but it is the wrong size
237 void *bloblist_find(uint tag, int size);
240 * bloblist_add() - Add a new blob
242 * Add a new blob to the bloblist
244 * This should only be called if you konw there is no existing blob for a
245 * particular tag. It is typically safe to call in the first phase of U-Boot
246 * (e.g. TPL or SPL). After that, bloblist_ensure() should be used instead.
248 * @tag: Tag to add (enum bloblist_tag_t)
249 * @size: Size of the blob
250 * @align: Alignment of the blob (in bytes), 0 for default
251 * Return: pointer to the newly added block, or NULL if there is not enough
254 void *bloblist_add(uint tag, int size, int align);
257 * bloblist_ensure_size() - Find or add a blob
259 * Find an existing blob, or add a new one if not found
261 * @tag: Tag to add (enum bloblist_tag_t)
262 * @size: Size of the blob
263 * @blobp: Returns a pointer to blob on success
264 * @align: Alignment of the blob (in bytes), 0 for default
265 * Return: 0 if OK, -ENOSPC if it is missing and could not be added due to lack
266 * of space, or -ESPIPE it exists but has the wrong size
268 int bloblist_ensure_size(uint tag, int size, int align, void **blobp);
271 * bloblist_ensure() - Find or add a blob
273 * Find an existing blob, or add a new one if not found
275 * @tag: Tag to add (enum bloblist_tag_t)
276 * @size: Size of the blob
277 * Return: pointer to blob, or NULL if it is missing and could not be added due
278 * to lack of space, or it exists but has the wrong size
280 void *bloblist_ensure(uint tag, int size);
283 * bloblist_ensure_size_ret() - Find or add a blob
285 * Find an existing blob, or add a new one if not found
287 * @tag: Tag to add (enum bloblist_tag_t)
288 * @sizep: Size of the blob to create; returns size of actual blob
289 * @blobp: Returns a pointer to blob on success
290 * Return: 0 if OK, -ENOSPC if it is missing and could not be added due to lack
293 int bloblist_ensure_size_ret(uint tag, int *sizep, void **blobp);
296 * bloblist_resize() - resize a blob
298 * Any blobs above this one are relocated up or down. The resized blob remains
301 * @tag: Tag to add (enum bloblist_tag_t)
302 * @new_size: New size of the blob (>0 to expand, <0 to contract)
303 * Return: 0 if OK, -ENOSPC if the bloblist does not have enough space, -ENOENT
304 * if the tag is not found
306 int bloblist_resize(uint tag, int new_size);
309 * bloblist_new() - Create a new, empty bloblist of a given size
311 * @addr: Address of bloblist
312 * @size: Initial size for bloblist
313 * @flags: Flags to use for bloblist
314 * Return: 0 if OK, -EFAULT if addr is not aligned correctly, -ENOSPC is the
315 * area is not large enough
317 int bloblist_new(ulong addr, uint size, uint flags);
320 * bloblist_check() - Check if a bloblist exists
322 * @addr: Address of bloblist
323 * @size: Expected size of blobsize, or 0 to detect the size
324 * Return: 0 if OK, -ENOENT if the magic number doesn't match (indicating that
325 * there problem is no bloblist at the given address), -EPROTONOSUPPORT
326 * if the version does not match, -EIO if the checksum does not match,
327 * -EFBIG if the expected size does not match the detected size, -ENOSPC
328 * if the size is not large enough to hold the headers
330 int bloblist_check(ulong addr, uint size);
333 * bloblist_finish() - Set up the bloblist for the next U-Boot part
335 * This sets the correct checksum for the bloblist. This ensures that the
336 * bloblist will be detected correctly by the next phase of U-Boot.
340 int bloblist_finish(void);
343 * bloblist_get_stats() - Get information about the bloblist
345 * This returns useful information about the bloblist
347 * @basep: Returns base address of bloblist
348 * @sizep: Returns the number of bytes used in the bloblist
349 * @allocedp: Returns the total space allocated to the bloblist
351 void bloblist_get_stats(ulong *basep, ulong *sizep, ulong *allocedp);
354 * bloblist_get_base() - Get the base address of the bloblist
356 * Return: base address of bloblist
358 ulong bloblist_get_base(void);
361 * bloblist_get_size() - Get the size of the bloblist
363 * Return: the size in bytes
365 ulong bloblist_get_size(void);
368 * bloblist_show_stats() - Show information about the bloblist
370 * This shows useful information about the bloblist on the console
372 void bloblist_show_stats(void);
375 * bloblist_show_list() - Show a list of blobs in the bloblist
377 * This shows a list of blobs, showing their address, size and tag.
379 void bloblist_show_list(void);
382 * bloblist_tag_name() - Get the name for a tag
385 * Return: name of tag, or "invalid" if an invalid tag is provided
387 const char *bloblist_tag_name(enum bloblist_tag_t tag);
390 * bloblist_reloc() - Relocate the bloblist and optionally resize it
392 * @to: Pointer to new bloblist location (must not overlap old location)
393 * @to_size: New size for bloblist (must be larger than from_size)
394 * @from: Pointer to bloblist to relocate
395 * @from_size: Size of bloblist to relocate
397 void bloblist_reloc(void *to, uint to_size, void *from, uint from_size);
400 * bloblist_init() - Init the bloblist system with a single bloblist
402 * This locates and sets up the blocklist for use.
404 * If CONFIG_BLOBLIST_FIXED is selected, it uses CONFIG_BLOBLIST_ADDR and
405 * CONFIG_BLOBLIST_SIZE to set up a bloblist for use by U-Boot.
407 * If CONFIG_BLOBLIST_ALLOC is selected, it allocates memory for a bloblist of
408 * size CONFIG_BLOBLIST_SIZE.
410 * If CONFIG_BLOBLIST_PASSAGE is selected, it uses the bloblist in the incoming
411 * standard passage. The size is detected automatically so CONFIG_BLOBLIST_SIZE
414 * Return: 0 if OK, -ve on error
416 int bloblist_init(void);
418 #endif /* __BLOBLIST_H */