coreboot-kgpe-d16/src/include/cbfs.h

400 lines
16 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef _CBFS_H_
#define _CBFS_H_
#include <cbmem.h>
#include <commonlib/bsd/cbfs_mdata.h>
#include <commonlib/mem_pool.h>
#include <commonlib/region.h>
#include <endian.h>
#include <program_loading.h>
#include <types.h>
#include <vb2_sha.h>
/**********************************************************************************************
* CBFS FILE ACCESS APIs *
**********************************************************************************************/
/*
* These are the APIs used to access files in CBFS. In order to keep the calls simple and free
* of clutter in the common cases, but still offer all advanced functionality when needed, there
* are many different variations that are implemented by wrapping the same underlying API with
* static inlines. All accessors have in common that they look up files by name, and will
* transparently decompress files that are compressed.
*
* There are three main flavors of CBFS accessors:
*
* size_t cbfs_load(char *name, void *buf, size_t size): Loads the contents of a CBFS file into
* a buffer provided by the caller (by providing pointer and size to it). Will return the
* amount of bytes loaded on success, or 0 on error.
*
* void *cbfs_map(char *name, size_t *size_out): Maps a file into the address space. If the file
* is not compressed and the platform supports direct memory-mapping for the boot medium,
* a pointer to the platform mapping is returned directly. In all other cases, memory will
* be allocated from the cbfs_cache and file data will be loaded into there. Returns a
* pointer to the mapping on success, or NULL on error. If an optional size_out parameter
* is passed in, it will be filled out with the size of the mapped data. Caller should call
* cbfs_unmap() after it is done using the mapping to free up the cbfs_cache if possible.
*
* void *cbfs_alloc(char *name, cbfs_allocator_t allocator, void *arg, size_t *size_out): Loads
* file data into memory provided by a custom allocator function that the caller passes in.
* The caller may pass an argument that is passed through verbatim to the allocator.
* Returns the pointer returned by the allocator (where the file data was loaded to) on
* success, or NULL on error. If an optional size_out parameter is passed in, it will be
* filled out with the size of the loaded data.
*
* void *cbfs_cbmem_alloc(char *name, uint32_t cbmem_id, size_t *size_out): Wrapper around
* cbfs_alloc() that will provide an allocator function for allocating space for the file
* data in CBMEM, with the provided CBMEM ID.
*
* All of these flavors have variations with any of the following optional parameters added:
*
* ..._ro_...: Will force looking up the CBFS file in the read-only CBFS (the "COREBOOT" FMAP
* section), even when running in an RW stage from one of the RW CBFSs. Only relevant if
* CONFIG(VBOOT) is set.
*
* ..._unverified_area_...: Will look for the CBFS file in the named FMAP area, rather than
* any of the default (RO or RW) CBFSs. Files accessed this way are *not* verified in any
* way (even if CONFIG(CBFS_VERIFICATION) is enabled) and should always be treated as
* untrusted (potentially malicious) data. Mutually exclusive with the ..._ro_... variant.
*
* ..._type_...: May pass in an extra enum cbfs_type *type parameter. If the value it points to
* is CBFS_TYPE_QUERY, it will be replaced with the actual CBFS type of the found file. If
* it is anything else, the type will be compared with the actually found type, and the
* operation will fail if they don't match.
*/
/*
* An allocator function for passing to cbfs_alloc(). Takes the argument that was originally
* passed to cbfs_alloc(), the size of the file to be loaded, and a pointer to the already
* loaded and verified file metadata (for rare cases where the allocator needs to check custom
* attributes). Must return a pointer to space of the requested size where the file data should
* be loaded, or NULL to make the operation fail.
*/
typedef void *(*cbfs_allocator_t)(void *arg, size_t size, const union cbfs_mdata *mdata);
static inline size_t cbfs_load(const char *name, void *buf, size_t size);
static inline size_t cbfs_ro_load(const char *name, void *buf, size_t size);
static inline size_t cbfs_type_load(const char *name, void *buf, size_t size,
enum cbfs_type *type);
static inline size_t cbfs_ro_type_load(const char *name, void *buf, size_t size,
enum cbfs_type *type);
static inline size_t cbfs_unverified_area_load(const char *area, const char *name,
void *buf, size_t size);
static inline void *cbfs_map(const char *name, size_t *size_out);
static inline void *cbfs_ro_map(const char *name, size_t *size_out);
static inline void *cbfs_type_map(const char *name, size_t *size_out, enum cbfs_type *type);
static inline void *cbfs_ro_type_map(const char *name, size_t *size_out, enum cbfs_type *type);
static inline void *cbfs_unverified_area_map(const char *area, const char *name,
size_t *size_out);
static inline void *cbfs_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out);
static inline void *cbfs_ro_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out);
static inline void *cbfs_type_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out, enum cbfs_type *type);
static inline void *cbfs_ro_type_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out, enum cbfs_type *type);
static inline void *cbfs_unverified_area_alloc(const char *area, const char *name,
cbfs_allocator_t allocator, void *arg,
size_t *size_out);
static inline void *cbfs_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out);
static inline void *cbfs_ro_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out);
static inline void *cbfs_type_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out,
enum cbfs_type *type);
static inline void *cbfs_ro_type_cbmem_alloc(const char *name, uint32_t cbmem_id,
size_t *size_out, enum cbfs_type *type);
static inline void *cbfs_unverified_area_cbmem_alloc(const char *area, const char *name,
uint32_t cbmem_id, size_t *size_out);
/*
* Starts the processes of preloading a file into RAM.
*
* This method depends on COOP_MULTITASKING to parallelize the loading. This method is only
* effective when the underlying rdev supports DMA operations.
*
* When `cbfs_load`, `cbfs_alloc`, or `cbfs_map` are called after a preload has been started,
* they will wait for the preload to complete (if it hasn't already) and then perform
* verification and/or decompression.
*
* This method does not have a return value because the system should boot regardless if this
* method succeeds or fails.
*/
void cbfs_preload(const char *name);
/* Removes a previously allocated CBFS mapping. Should try to unmap mappings in strict LIFO
order where possible, since mapping backends often don't support more complicated cases. */
void cbfs_unmap(void *mapping);
/* Load stage into memory filling in prog. Return 0 on success. < 0 on error. */
enum cb_err cbfs_prog_stage_load(struct prog *prog);
/* Returns the size of a CBFS file, or 0 on error. Avoid using this function to allocate space,
and instead use cbfs_alloc() so the file only needs to be looked up once. */
static inline size_t cbfs_get_size(const char *name);
static inline size_t cbfs_ro_get_size(const char *name);
/* Returns the type of a CBFS file, or CBFS_TYPE_NULL on error. Use cbfs_type_load() instead of
this where possible to avoid looking up the file more than once. */
static inline enum cbfs_type cbfs_get_type(const char *name);
static inline enum cbfs_type cbfs_ro_get_type(const char *name);
/* Check whether a CBFS file exists. */
static inline bool cbfs_file_exists(const char *name);
static inline bool cbfs_ro_file_exists(const char *name);
/**********************************************************************************************
* BOOT DEVICE HELPER APIs *
**********************************************************************************************/
/*
* The shared memory pool for backing mapped CBFS files, and other CBFS allocation needs.
*/
extern struct mem_pool cbfs_cache;
/*
* Data structure that represents "a" CBFS boot device, with optional metadata cache. Generally
* we only have one of these, or two (RO and RW) when CONFIG(VBOOT) is set. The region device
* stored here must always be a subregion of boot_device_ro().
*/
struct cbfs_boot_device {
struct region_device rdev;
void *mcache;
size_t mcache_size;
};
/* Helper to fill out |mcache| and |mcache_size| in a cbfs_boot_device. */
void cbfs_boot_device_find_mcache(struct cbfs_boot_device *cbd, uint32_t id);
/*
* Retrieves the currently active CBFS boot device. If |force_ro| is set, will always return the
* read-only CBFS instead (this only makes a difference when CONFIG(VBOOT) is enabled). May
* perform certain CBFS initialization tasks. Returns NULL on error (e.g. boot device IO error).
*/
const struct cbfs_boot_device *cbfs_get_boot_device(bool force_ro);
/*
* Builds the mcache (if |cbd->mcache| is set) and verifies |metadata_hash| (if it is not NULL).
* If CB_CBFS_CACHE_FULL is returned, the mcache is incomplete but still valid and the metadata
* hash was still verified. Should be called once per *boot* (not once per stage) before the
* first CBFS access.
*/
enum cb_err cbfs_init_boot_device(const struct cbfs_boot_device *cbd,
struct vb2_hash *metadata_hash);
/**********************************************************************************************
* INTERNAL HELPERS FOR INLINES, DO NOT USE. *
**********************************************************************************************/
enum cb_err _cbfs_boot_lookup(const char *name, bool force_ro,
union cbfs_mdata *mdata, struct region_device *rdev);
void *_cbfs_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out, bool force_ro, enum cbfs_type *type);
void *_cbfs_unverified_area_alloc(const char *area, const char *name,
cbfs_allocator_t allocator, void *arg, size_t *size_out);
struct _cbfs_default_allocator_arg {
void *buf;
size_t buf_size;
};
void *_cbfs_default_allocator(void *arg, size_t size, const union cbfs_mdata *unused);
void *_cbfs_cbmem_allocator(void *arg, size_t size, const union cbfs_mdata *unused);
/**********************************************************************************************
* INLINE IMPLEMENTATIONS *
**********************************************************************************************/
static inline void *cbfs_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out)
{
return cbfs_type_alloc(name, allocator, arg, size_out, NULL);
}
static inline void *cbfs_ro_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out)
{
return cbfs_ro_type_alloc(name, allocator, arg, size_out, NULL);
}
static inline void *cbfs_type_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out, enum cbfs_type *type)
{
return _cbfs_alloc(name, allocator, arg, size_out, false, type);
}
static inline void *cbfs_ro_type_alloc(const char *name, cbfs_allocator_t allocator, void *arg,
size_t *size_out, enum cbfs_type *type)
{
return _cbfs_alloc(name, allocator, arg, size_out, true, type);
}
static inline void *cbfs_unverified_area_alloc(const char *area, const char *name,
cbfs_allocator_t allocator, void *arg,
size_t *size_out)
{
return _cbfs_unverified_area_alloc(area, name, allocator, arg, size_out);
}
static inline void *cbfs_map(const char *name, size_t *size_out)
{
return cbfs_type_map(name, size_out, NULL);
}
static inline void *cbfs_ro_map(const char *name, size_t *size_out)
{
return cbfs_ro_type_map(name, size_out, NULL);
}
static inline void *cbfs_type_map(const char *name, size_t *size_out, enum cbfs_type *type)
{
return cbfs_type_alloc(name, NULL, NULL, size_out, type);
}
static inline void *cbfs_ro_type_map(const char *name, size_t *size_out, enum cbfs_type *type)
{
return cbfs_ro_type_alloc(name, NULL, NULL, size_out, type);
}
static inline void *cbfs_unverified_area_map(const char *area, const char *name,
size_t *size_out)
{
return _cbfs_unverified_area_alloc(area, name, NULL, NULL, size_out);
}
static inline size_t _cbfs_load(const char *name, void *buf, size_t size, bool force_ro,
enum cbfs_type *type)
{
struct _cbfs_default_allocator_arg arg = { .buf = buf, .buf_size = size };
if (_cbfs_alloc(name, _cbfs_default_allocator, &arg, &size, force_ro, type))
return size;
else
return 0;
}
static inline size_t cbfs_load(const char *name, void *buf, size_t size)
{
return cbfs_type_load(name, buf, size, NULL);
}
static inline size_t cbfs_type_load(const char *name, void *buf, size_t size,
enum cbfs_type *type)
{
return _cbfs_load(name, buf, size, false, type);
}
static inline size_t cbfs_ro_load(const char *name, void *buf, size_t size)
{
return cbfs_ro_type_load(name, buf, size, NULL);
}
static inline size_t cbfs_ro_type_load(const char *name, void *buf, size_t size,
enum cbfs_type *type)
{
return _cbfs_load(name, buf, size, true, type);
}
static inline size_t cbfs_unverified_area_load(const char *area, const char *name,
void *buf, size_t size)
{
struct _cbfs_default_allocator_arg arg = { .buf = buf, .buf_size = size };
if (_cbfs_unverified_area_alloc(area, name, _cbfs_default_allocator, &arg, &size))
return size;
else
return 0;
}
static inline void *cbfs_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out)
{
return cbfs_type_cbmem_alloc(name, cbmem_id, size_out, NULL);
}
static inline void *cbfs_ro_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out)
{
return cbfs_ro_type_cbmem_alloc(name, cbmem_id, size_out, NULL);
}
static inline void *cbfs_type_cbmem_alloc(const char *name, uint32_t cbmem_id, size_t *size_out,
enum cbfs_type *type)
{
return cbfs_type_alloc(name, _cbfs_cbmem_allocator, (void *)(uintptr_t)cbmem_id,
size_out, type);
}
static inline void *cbfs_ro_type_cbmem_alloc(const char *name, uint32_t cbmem_id,
size_t *size_out, enum cbfs_type *type)
{
return cbfs_ro_type_alloc(name, _cbfs_cbmem_allocator, (void *)(uintptr_t)cbmem_id,
size_out, type);
}
static inline void *cbfs_unverified_area_cbmem_alloc(const char *area, const char *name,
uint32_t cbmem_id, size_t *size_out)
{
return _cbfs_unverified_area_alloc(area, name, _cbfs_cbmem_allocator,
(void *)(uintptr_t)cbmem_id, size_out);
}
static inline size_t cbfs_get_size(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, false, &mdata, &rdev) != CB_SUCCESS)
return 0;
return be32toh(mdata.h.len);
}
static inline size_t cbfs_ro_get_size(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, true, &mdata, &rdev) != CB_SUCCESS)
return 0;
return be32toh(mdata.h.len);
}
static inline enum cbfs_type cbfs_get_type(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, false, &mdata, &rdev) != CB_SUCCESS)
return CBFS_TYPE_NULL;
return be32toh(mdata.h.type);
}
static inline enum cbfs_type cbfs_ro_get_type(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, true, &mdata, &rdev) != CB_SUCCESS)
return CBFS_TYPE_NULL;
return be32toh(mdata.h.type);
}
static inline bool cbfs_file_exists(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, false, &mdata, &rdev) != CB_SUCCESS)
return false;
return true;
}
static inline bool cbfs_ro_file_exists(const char *name)
{
union cbfs_mdata mdata;
struct region_device rdev;
if (_cbfs_boot_lookup(name, true, &mdata, &rdev) != CB_SUCCESS)
return false;
return true;
}
#endif