I have almost identical code except I'm running on a mips based platform with a 16550 UART so I don't use the shift parameter. I do the regs->writes() but when I peek at the physical memory with GDB I don't see the values I wrote. The l4io_request_iomem() is called with L4IO_MEM_NONCACHED (and there is no enabled cache in my setup) and it doesn't return an error. I doesn't look like the values are getting written to the mmio block.
On Mon, May 4, 2015 at 4:05 AM, Pflaum, Clemens clemens.pflaum@mytum.de wrote:
Hi,
How does the 'no access' show? J12 is described as having UART7 so I'd
assume the UART is there. (UART4 starts on a new page, you have mapped that too?)
If I try to read any register like I usally do: char sc = regs->read<unsigned char>(LCR); printf("0x0C LCR: %#010x\n", sc); All i get is 0x00 even if i try writing to it before. I have had the exact same problem with UART0-3 before manually adjusting the Registers to their actual offsets or setting the shift parameter of Io_register_block_mmio to 2. So its actually like I'm looking at/writing to the wrong places. I map the memory similar to the serial-drv example only ever one UART at a time: #define IRQ_NUM 52 //currently set to UART7, 36 for UART3 #define UART_BASE 0x01C29C00 //currently set to UART7, 0x01C28C00 for UART3
bool Maestro_server::init() { printf("init start\n"); l4_addr_t virt_base = 0;
if (l4io_request_iomem((l4_addr_t)UART_BASE, 0x0400,
L4IO_MEM_NONCACHED, &virt_base)) { printf("maestro-drv: request io-memory from l4io failed.\n"); return false; } printf("maestro-drv: virtual base at:%lx\n", virt_base);
L4::Io_register_block_mmio *regs = new
L4::Io_register_block_mmio(virt_base, 2); printf("registered regs\n");
_uart = new (malloc(sizeof(L4::Uart_bpi16550)))
L4::Uart_bpi16550((unsigned long) 115200); printf("malloc for _uart\n"); printf("\n");
if(!(_uart->startup(regs))){ printf("failed to startup uart regs!\n"); } . .
}
Together with the folling in my .devs file
local Hw = Io.Hw local Res = Io.Res Io.hw_add_devices { UART7 = Hw.Device { hid = "UART7"; Res.irq(52); Res.mmio(0x01C29C00, 0x01C29FFF);
} }
Hmm, does it work with on Linux, i.e. it's not something
hardware-related?
I have tested the UARTS with the Bananian linux and they work just fine, so it cant be hardware-related.
Regards, Clemens
l4-hackers mailing list l4-hackers@os.inf.tu-dresden.de http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers