/**
* A generic implementation of bhnd_nvram_data_getvar().
*
* This implementation will call bhnd_nvram_data_getvar_ptr() to fetch
* a pointer to the variable data and perform data coercion on behalf
* of the caller.
*
* If a variable definition for the requested variable is available via
* bhnd_nvram_find_vardefn(), the definition will be used to provide a
* formatting instance to bhnd_nvram_val_init().
*/
int
bhnd_nvram_data_generic_rp_getvar(struct bhnd_nvram_data *nv, void *cookiep,
void *outp, size_t *olen, bhnd_nvram_type otype)
{
bhnd_nvram_val val;
const bhnd_nvram_val_fmt *fmt;
const void *vptr;
bhnd_nvram_type vtype;
size_t vlen;
int error;
BHND_NV_ASSERT(bhnd_nvram_data_caps(nv) & BHND_NVRAM_DATA_CAP_READ_PTR,
("instance does not advertise READ_PTR support"));
/* Fetch variable data and value format*/
vptr = bhnd_nvram_data_getvar_ptr_info(nv, cookiep, &vlen, &vtype,
&fmt);
if (vptr == NULL)
return (EINVAL);
/* Attempt value coercion */
error = bhnd_nvram_val_init(&val, fmt, vptr, vlen, vtype,
BHND_NVRAM_VAL_BORROW_DATA);
if (error)
return (error);
error = bhnd_nvram_val_encode(&val, outp, olen, otype);
/* Clean up */
bhnd_nvram_val_release(&val);
return (error);
}
/**
* Coerce value @p inp of type @p itype to @p otype, writing the
* result to @p outp.
*
* @param inp The value to be coerced.
* @param ilen The size of @p inp, in bytes.
* @param itype The base data type of @p inp.
* @param[out] outp On success, the value will be written to this
* buffer. This argment may be NULL if the value
* is not desired.
* @param[in,out] olen The capacity of @p outp. On success, will be set
* to the actual size of the requested value.
* @param otype The data type to be written to @p outp.
*
* @retval 0 success
* @retval ENOMEM If @p outp is non-NULL and a buffer of @p olen is too
* small to hold the requested value.
* @retval EFTYPE If the variable data cannot be coerced to @p otype.
* @retval ERANGE If value coercion would overflow @p otype.
*/
int
bhnd_nvram_value_coerce(const void *inp, size_t ilen, bhnd_nvram_type itype,
void *outp, size_t *olen, bhnd_nvram_type otype)
{
bhnd_nvram_val_t val;
int error;
/* Wrap input buffer in a value instance */
error = bhnd_nvram_val_init(&val, NULL, inp, ilen,
itype, BHND_NVRAM_VAL_BORROW_DATA|BHND_NVRAM_VAL_FIXED);
if (error)
return (error);
/* Try to encode as requested type */
error = bhnd_nvram_val_encode(&val, outp, olen, otype);
/* Clean up and return error */
bhnd_nvram_val_release(&val);
return (error);
}
