Using a second UART to control a serial device
clemens.pflaum at mytum.de
Fri Apr 17 12:03:46 CEST 2015
Hi L4 Hackers,
Im currently running Fiasco.OC with L4Re on my BananaPi. I'm trying to
control a serial device (Pololu Servo Controller) by sending a small
series of Bytes over a second UART ( not UART 0 since im getting the
console from there ). Via documentation I've found out that UART 3 is at
0x01C28C00 and is a U6_16550A, so I'm hoping the driver in
/pkg/drivers-frst/uart/src/uart_pxa.cc will be compatible with that.
Where and how would I have to go about initiating my UART 3? By writing
a new platform for BPi in /pkg/bootstrap/server/src/platform? The
function set_stdio_uart(&_uart); made me think its only the "console"
UART. Or do I have to instantiate some kind of Hw.Device like the gpio
in /pkg/io/config/arm-omap3.devs and put it on a new vBus like in
Or am I thinking way too complicated and it is as simple as editing the
int irq_num = 37;
// How can i find out what this number refers to/do i have to
change it at all?
l4_addr_t phys_base = 0x1000a000;
// change to 0x01C28C00
int irq_num = 74;
l4_addr_t phys_base = 0x49020000;
l4_addr_t virt_base = 0;
if (l4io_request_iomem(phys_base, 0x1000, L4IO_MEM_NONCACHED,
printf("serial-drv: request io-memory from l4io failed.\n");
printf("serial-drv: virtual base at:%lx\n", virt_base);
L4::Io_register_block_mmio *regs = new
_uart = new (malloc(sizeof(L4::Uart_pl011))) L4::Uart_pl011(24019200);
//change to L4::Uart_pxa(what does this number mean?)
Thanks for any answers in advance.
Clemens c... at mytum.de
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