Hello all, the driver works after hours of problem seeking in incorrect directions.
I have debugged, examined and patched both, RTEMS and QEMU. The main problem is quite simple. Update of RTEMS interrupts processing disable level type interrupts when they arrive and the driver/daemon has to re-enable interrupt source on the interrupt controller level. Generally, idea to disable interrupt source at hard interrupt time and do all processing outside of interrupt is the the best solution for RT system. But I consider actual behavior seriously broken. It is for longer description. But if you consider shared interrupts (all PCI ones on PC for example) then the correct behavior is to use hard IRQ to disable/gate interrupt on given device level (not all sharing devices at controller level) and release worker thread for each device from corresponding hard IRQ and left the scheduler to select between these according to the priority. When more important/critical device finishes its IRQ processing, it enables IRQ on given device level and processing of its interrupts in time is possible. Actual state pushes device drivers to attempt re-enable IRQ on controller level. But if IRQ is re-enabled by hight priority device worker thread in case that there exists lower priority device sharing the IRQ which is still signalling IRQ, then without gating on device level this has to lead to livelock. Cotroller fires IRQ dispatch, that releases high priority device driver, that finds nothing to do and reenables IRQ on the controller level. There is option to make things work even with shared IRQs if gating on device level is not available. And it is to have counted disable on the controller level which ensures that IRQ is re-enabled only after all devices worker threads finish processing. But priority rules are broken in that case as well. I know that there is interrupt server option but base interrupts should be working and not broken. Shared edge trigerred interrupts processing is complex problem either. I think that I have provided analysis years ago for RTEMS. .... found it https://lists.rtems.org/pipermail/users/2008-May/018775.html If I could find month somewhere, I would try provide changes which could go under critique and testing ..... Anyway, back to solve Saeed Ehteshamifar problem with lack of network supporting environment for his dynamic loading task. I have tested it on Linux, Debian. I have done setup without helper scripts and toolsfrom QEMU or other system. I decided to use separate "network segment" for testing. The wire for L2/ethernet layer is created by ip tuntap add tap1 mode tap user pi ip link set tap1 up You need root access. I have connected this stub to Linux TCP/IP networking subsystem by ip addr add 192.168.3.1/24 dev tap1 ip link set tap1 up You need to select address from private address range. Check that whole range, in above case 192.168.3.0 to 192.168.3.255 does not overlap with networks visible from your computer. It should be really isolated island. The kernel does default setup of routing to the range ip route show 192.168.3.0/24 dev tap1 proto kernel scope link src 192.168.3.1 To keep range separate you should not have enabled forwarding cat /proc/sys/net/ipv4/ip_forward should show 0 or you need to setup iptables or check and set routing rules to keep island network. I start RTEMS application by command qemu-system-x86_64 -enable-kvm -kernel $APP_BINARY \ -vga cirrus \ -append "--console=/dev/com1" \ -serial stdio \ -net nic,vlan=1,macaddr=be:be:be:10:00:01,model=i82557b \ -net tap,ifname=tap1,vlan=1,script=no,downscript=no \ You can add "-s -S" for debugging by GDB "target remote localhost:1234" Be carefull, if you want to set breakpoints then setting them when in real mode at address 0xffff0 is not good idea. You need to be in virtual space of RTEMS application after its load to set software breakpoints. But there are two or three HW breakpoints emulated. Decide for some function and use hbreak rtems_fxp_attach c When the function is reached you can insert regular SW breakpoints. When application runs, you can access it from Linux system. The configured address has to be withing island network range. I.e. ping 192.168.3.66 The netwok card should be found by ARP broadcast coming to QEMU where RTEMS responds that it is its address. You can use arping -i tap1 192.168.3.66 or arping -i tap1 be:be:be:10:00:01 to check lowest level connection. The OMK template includes application "appnet" which uses RTEMS integrated telnet to access RTEMS shell remotely. telnet 192.168.3.66 See http://rtime.felk.cvut.cz/gitweb/rtems-devel.git/tree/HEAD:/rtems-omk-template/appnet The config static struct rtems_bsdnet_ifconfig netdriver_config = { .name = "fxp1" /*RTEMS_BSP_NETWORK_DRIVER_NAME*/, .attach = rtems_fxp_attach /*RTEMS_BSP_NETWORK_DRIVER_ATTACH*/, .next = NULL, .ip_address = "192.168.3.66", .ip_netmask = "255.255.255.0", .hardware_address = ethernet_address, .ignore_broadcast = 0, .mtu = 0, .rbuf_count = 0, .xbuf_count = 0, .port = 0, .irno = 0, .bpar = 0, .drv_ctrl = NULL }; struct rtems_bsdnet_config rtems_bsdnet_config = { .ifconfig = &netdriver_config, /* .bootp = rtems_bsdnet_do_bootp,*/ /* .bootp = rtems_bsdnet_do_dhcp,*/ #if 0 .bootp = rtems_bsdnet_do_dhcp_failsafe, #endif .network_task_priority = 0, /* 100 */ #if 1 .mbuf_bytecount = 256 * 1024, /* 64 kbytes */ .mbuf_cluster_bytecount = 256 * 1024, /* 128 kbytes */ #else .mbuf_bytecount = 2048 * 1024, /* 2 MB */ .mbuf_cluster_bytecount = 2048 * 1024, /* 2 MB */ #endif .hostname = NULL, .domainname = NULL, .gateway = "192.168.3.1", .log_host = NULL, .name_server = { "NULL" }, .ntp_server = { "NULL" }, .sb_efficiency = 0, .udp_tx_buf_size = 0, /* UDP TX: 9216 bytes */ .udp_rx_buf_size = 0, /* UDP RX: 40 * (1024 + sizeof(struct sockaddr_in)) */ .tcp_tx_buf_size = 0, /* TCP TX: 16 * 1024 bytes */ .tcp_rx_buf_size = 0, /* TCP TX: 16 * 1024 bytes */ }; This is for static IP addresses on isolated island network. You can interconnect the island with external systems over that IP level forwarding or use ETHERNEL level bridge. Something like brctl addbr my_bridge ip link set my_bridge up brctl addif my_bridge eth0 brctl addif my_bridge tap1 brctl show my_bridge or by newer command ip link add my_bridge type bridge ip link set tap1 master my_bridge ip link set dev eth0 down ip addr flush dev eth0 ip link set dev eth0 up ip link set eth0 master my_bridge ip link set dev my_bridge up If you do not need to connect to the system running under QEMU from host system, then you can use simple NAT integrated in QEMU for outgoing connections. QEMU options -net nic,vlan=1,macaddr=be:be:be:10:00:01,model=i82557b \ -net user,vlan=1 \ Best wishes, Pavel PS: it would be nice to have some example for libbsd based x86 or other arch QEMU setup on Linux. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel