When chainloading rtl8139.pxe from an old Etherboot rtl8139.zrom, iPXE
can end up misreading the first word of the MAC address from the
EEPROM as being all zeroes. This is presumably because Etherboot has
left the serial EEPROM in an unexpected state.
Fix by using the chip select line to reset the SPI device before we
start accessing it.
Reported-by: Mandar U Jog <mandarjog@gmail.com>
Tested-by: Mandar U Jog <mandarjog@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several SPI chips will respond to an SPI read command with a dummy
zero bit immediately prior to the first real data bit. This can be
used to autodetect the address length, provided that the command
length and data length are already known, and that the MISO data line
is tied high.
Tested-by: Thomas Miletich <thomas.miletich@gmail.com>
Debugged-by: Thomas Miletich <thomas.miletich@gmail.com>
Some devices (e.g. the Atmel AT24C11) have no concept of a device
address; they respond to every device address and use this value as
the word address. Some other devices use part of the device address
field to extend the word address field.
Generalise the i2c bit-bashing support to handle this by defining the
device address length and word address length as properties of an i2c
device. The word address is assumed to overflow into the device
address field if the address used exceeds the width of the word
address field.
Also add a bus reset mechanism. i2c chips don't usually have a reset
line, so rebooting the host will not clear any bizarre state that the
chip may be in. We reset the bus by clocking SCL until we see SDA
high, at which point we know we can generate a start condition and
have it seen by all devices. We then generate a stop condition to
leave the bus in a known state prior to use.
Finally, add some extra debugging messages to i2c_bit.c.
defined in vsprintf.h. (This may change, since vsprintf.h is a
non-standard name, but for now it's the one to use.)
There should be no need to include vsprintf.h just for DBG() statements,
since include/compiler.h forces it in for a debug build anyway.
Michael Brown