From 9f407d4ef092c2ce7ab0f4f366aee252611dab3c Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Thu, 15 Nov 2018 18:43:50 -0700 Subject: Add core support for a bloblist to convey data from SPL At present there is no standard way in U-Boot to pass information from SPL to U-Boot proper. But sometimes SPL wants to convey information to U-Boot that U-Boot cannot easily figure out. For example, if SPL sets up SDRAM then it might want to pass the size of SDRAM, or the location of each bank, to U-Boot proper. Add a new 'bloblist' feature which provides this. A bloblist is set up in the first phase of U-Boot that runs (i.e. TPL or SPL). The location of this info may be in SRAM or CAR (x86 cache-as-RAM) or somewhere else. Information placed in this region is preserved (with a checksum) through TPL and SPL and ends up in U-Boot. At this point it is copied into SDRAM so it can be used after relocation. Reviewed-by: Tom Rini Signed-off-by: Simon Glass Acked-by: Andreas Dannenberg --- include/bloblist.h | 195 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 include/bloblist.h (limited to 'include/bloblist.h') diff --git a/include/bloblist.h b/include/bloblist.h new file mode 100644 index 0000000000..85144010ab --- /dev/null +++ b/include/bloblist.h @@ -0,0 +1,195 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * This provides a standard way of passing information between boot phases + * (TPL -> SPL -> U-Boot proper.) + * + * A list of blobs of data, tagged with their owner. The list resides in memory + * and can be updated by SPL, U-Boot, etc. + * + * Copyright 2018 Google, Inc + * Written by Simon Glass + */ + +#ifndef __BLOBLIST_H +#define __BLOBLIST_H + +enum { + BLOBLIST_VERSION = 0, + BLOBLIST_MAGIC = 0xb00757a3, + BLOBLIST_ALIGN = 16, +}; + +enum bloblist_tag_t { + BLOBLISTT_NONE = 0, + + /* Vendor-specific tags are permitted here */ + BLOBLISTT_EC_HOSTEVENT, /* Chromium OS EC host-event mask */ + BLOBLISTT_SPL_HANDOFF, /* Hand-off info from SPL */ + BLOBLISTT_VBOOT_CTX, /* Chromium OS verified boot context */ + BLOBLISTT_VBOOT_HANDOFF, /* Chromium OS internal handoff info */ +}; + +/** + * struct bloblist_hdr - header for the bloblist + * + * This is stored at the start of the bloblist which is always on a 16-byte + * boundary. Records follow this header. The bloblist normally stays in the + * same place in memory as SPL and U-Boot execute, but it can be safely moved + * around. + * + * None of the bloblist structures contain pointers but it is possible to put + * pointers inside a bloblist record if desired. This is not encouraged, + * since it can make part of the bloblist inaccessible if the pointer is + * no-longer valid. It is better to just store all the data inside a bloblist + * record. + * + * Each bloblist record is aligned to a 16-byte boundary and follows immediately + * from the last. + * + * @version: BLOBLIST_VERSION + * @hdr_size: Size of this header, normally sizeof(struct bloblist_hdr). The + * first bloblist_rec starts at this offset from the start of the header + * @flags: Space for BLOBLISTF_... flags (none yet) + * @magic: BLOBLIST_MAGIC + * @size: Total size of all records (non-zero if valid) including this header. + * The bloblist extends for this many bytes from the start of this header. + * @alloced: Total size allocated for this bloblist. When adding new records, + * the bloblist can grow up to this size. This starts out as + * sizeof(bloblist_hdr) since we need at least that much space to store a + * valid bloblist + * @spare: Space space + * @chksum: CRC32 for the entire bloblist allocated area. Since any of the + * blobs can be altered after being created, this checksum is only valid + * when the bloblist is finalised before jumping to the next stage of boot. + * Note: @chksum is last to make it easier to exclude it from the checksum + * calculation. + */ +struct bloblist_hdr { + u32 version; + u32 hdr_size; + u32 flags; + u32 magic; + + u32 size; + u32 alloced; + u32 spare; + u32 chksum; +}; + +/** + * struct bloblist_rec - record for the bloblist + * + * NOTE: Only exported for testing purposes. Do not use this struct. + * + * The bloblist contains a number of records each consisting of this record + * structure followed by the data contained. Each records is 16-byte aligned. + * + * @tag: Tag indicating what the record contains + * @hdr_size: Size of this header, normally sizeof(struct bloblist_rec). The + * record's data starts at this offset from the start of the record + * @size: Size of record in bytes, excluding the header size. This does not + * need to be aligned (e.g. 3 is OK). + * @spare: Spare space for other things + */ +struct bloblist_rec { + u32 tag; + u32 hdr_size; + u32 size; + u32 spare; +}; + +/** + * bloblist_find() - Find a blob + * + * Searches the bloblist and returns the blob with the matching tag + * + * @tag: Tag to search for (enum bloblist_tag_t) + * @size: Expected size of the blob + * @return pointer to blob if found, or NULL if not found, or a blob was found + * but it is the wrong size + */ +void *bloblist_find(uint tag, int size); + +/** + * bloblist_add() - Add a new blob + * + * Add a new blob to the bloblist + * + * This should only be called if you konw there is no existing blob for a + * particular tag. It is typically safe to call in the first phase of U-Boot + * (e.g. TPL or SPL). After that, bloblist_ensure() should be used instead. + * + * @tag: Tag to add (enum bloblist_tag_t) + * @size: Size of the blob + * @return pointer to the newly added block, or NULL if there is not enough + * space for the blob + */ +void *bloblist_add(uint tag, int size); + +/** + * bloblist_ensure_size() - Find or add a blob + * + * Find an existing blob, or add a new one if not found + * + * @tag: Tag to add (enum bloblist_tag_t) + * @size: Size of the blob + * @blobp: Returns a pointer to blob on success + * @return 0 if OK, -ENOSPC if it is missing and could not be added due to lack + * of space, or -ESPIPE it exists but has the wrong size + */ +int bloblist_ensure_size(uint tag, int size, void **blobp); + +/** + * bloblist_ensure() - Find or add a blob + * + * Find an existing blob, or add a new one if not found + * + * @tag: Tag to add (enum bloblist_tag_t) + * @size: Size of the blob + * @return pointer to blob, or NULL if it is missing and could not be added due + * to lack of space, or it exists but has the wrong size + */ +void *bloblist_ensure(uint tag, int size); + +/** + * bloblist_new() - Create a new, empty bloblist of a given size + * + * @addr: Address of bloblist + * @size: Initial size for bloblist + * @flags: Flags to use for bloblist + * @return 0 if OK, -EFAULT if addr is not aligned correctly, -ENOSPC is the + * area is not large enough + */ +int bloblist_new(ulong addr, uint size, uint flags); + +/** + * bloblist_check() - Check if a bloblist exists + * + * @addr: Address of bloblist + * @size: Expected size of blobsize, or 0 to detect the size + * @return 0 if OK, -ENOENT if the magic number doesn't match (indicating that + * there problem is no bloblist at the given address), -EPROTONOSUPPORT + * if the version does not match, -EIO if the checksum does not match, + * -EFBIG if the expected size does not match the detected size + */ +int bloblist_check(ulong addr, uint size); + +/** + * bloblist_finish() - Set up the bloblist for the next U-Boot part + * + * This sets the correct checksum for the bloblist. This ensures that the + * bloblist will be detected correctly by the next phase of U-Boot. + * + * @return 0 + */ +int bloblist_finish(void); + +/** + * bloblist_init() - Init the bloblist system with a single bloblist + * + * This uses CONFIG_BLOBLIST_ADDR and CONFIG_BLOBLIST_SIZE to set up a bloblist + * for use by U-Boot. + */ +int bloblist_init(void); + +#endif /* __BLOBLIST_H */ -- cgit v1.2.3