Also we can enable m24c02 eeprom chip in dts-file e.g.
&i2c0 {
status = "okay";
eeprom: m24c02@50 {
compatible = "spd";
reg = <0x50>;
};
};
Alas! qemu mips malta spd m24c02 eeprom chip emulation is not perfect:
the block read operation does not work properly.
Here is an example.
If we read eeprom content byte-by-byte then there is no problem:
barebox:/ for i in 0x08 0x09 0x0a 0x0b 0x0c 0x0d 0x0e 0x0f ;
> do i2c_read -b 0 -a 0x50 -r $i -c 1 ; done
0x01
0x75
0x54
0x00
0x82
0x08
0x00
0x01
Compare this output with content of qemu.git/hw/mips/mips_malta.c:
static eeprom24c0x_t spd_eeprom = {
.contents = {
...
/* 00000008: */ 0x01,0x75,0x54,0x00,0x82,0x08,0x00,0x01,
But if we read several bytes at once the we have data corruption:
barebox:/ i2c_read -b 0 -a 0x50 -r 0x8 -c 8
0x01 0xff 0xff 0xff 0xff 0xff 0xff 0xff
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch adds CBUS UART dts support;
also it adds the necessary macros for DEBUG_LL.
qemu-malta supports three serial interfaces:
* two ports are provided by the FDC37M817
Super I/O; this chip is connected via LPC bus
to Intel 82371EB (PIIX4E) South Bridge;
* the third serial port is provided by
the discrete TI 16C550C (CBUS UART);
this chip is connected via CBUS directly
to the board's GT64120 North Bridge.
See Malta User's Manual (MD00048) for details.
CBUS UART Instructions for use:
1. Enable CONFIG_CONSOLE_ACTIVATE_ALL in .config
(or disable uart0 in dts) and compile barebox;
2. run qemu:
qemu-system-mips -nographic -nodefaults \
-monitor null -M malta -m 256 \
-serial null -serial null -serial stdio \
-bios barebox-flash-image
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
There are some reasons for using YAMON-style memory map:
* we can run Linux kernel from barebox;
* we can use GXemul for running barebox.
YAMON-style GT64120 memory map make move UART to the new position.
The files gt64120.h and mach-gt64120.h are imported from Linux.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Antony Pavlov