static uint64_t fw_cfg_data_read(void *opaque, hwaddr addr, unsigned size)
{
FWCfgState *s = opaque;
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
&s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
uint64_t value = 0;
assert(size > 0 && size <= sizeof(value));
if (s->cur_entry != FW_CFG_INVALID && e->data && s->cur_offset < e->len) {
/* The least significant 'size' bytes of the return value are
* expected to contain a string preserving portion of the item
* data, padded with zeros on the right in case we run out early.
* In technical terms, we're composing the host-endian representation
* of the big endian interpretation of the fw_cfg string.
*/
do {
value = (value << 8) | e->data[s->cur_offset++];
} while (--size && s->cur_offset < e->len);
/* If size is still not zero, we *did* run out early, so continue
* left-shifting, to add the appropriate number of padding zeros
* on the right.
*/
value <<= 8 * size;
}
trace_fw_cfg_read(s, value);
return value;
}
static uint8_t fw_cfg_read(FWCfgState *s)
{
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
uint8_t ret;
if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len)
ret = 0;
else
ret = e->data[s->cur_offset++];
trace_fw_cfg_read(s, ret);
return ret;
}
