US_FIDI_FI_DI_RATIO_Msk is 0x7ff,
cemu rejected >= 0x400 in emu_update_fidi() and masked with 0x3ff
in card_emu_uart_update_fidi(), but update_fidi() used by
the sniffer already used 0x7ff.
-> ratios 1024..2047 are unusable in cemu, which is the entire upper
half of ISO 7816-3 Table 7 at Di=1.
A reader trying one of those in a PPS gets the proposal echoed and
accepted, after which the card keeps transmitting at the old rate.
FI_DI_RATIO is clock periods per bit -> larger ratio is a SLOWER link.
The old check rejected slow values but accepted Fi=372/Di=64, ratio 5 !?
Unify and use the register mask (= shifed by 0 so usable as value) and
reject ratios that do not fit rather than truncating to garbage dividers.
Change-Id: I6211dd5be7c5c5d2150af2aa37a403b33e6d340d
Fi/Di are not the index into the table, but the contents of the table
as resolved by Fi_index / Di_index. Let's clarify the terminology.
Change-Id: If364e08e7c9a3a9707e6d54b9267c6a7c088e415
There have been tons of format-string related bugs in our code which
we never discovered due to disabling -Wformat. Let's fix that.
Change-Id: I5ec466361bcc526fac1f4897673264ee5af3458b