readme.md

Board mps2_an385 (ARM Cortex-M3 AN385)

TODO:

• Add support for CCM SRAM
• Integrate SLIP protocol for networking

Glossary:

• CMSDK: Code Model Software Development Kit
• FVP: Fast Models Fixed Virtual Platforms
• SMM: Soft Macro Model

Related:

• https://docs.zephyrproject.org/2.6.0/boards/arm/mps2_an385/doc/index.html
• https://docs.zephyrproject.org/3.0.0/guides/networking/qemu_eth_setup.html#networking-with-eth-qemu
• https://github.com/zephyrproject-rtos/zephyr/blob/main/boards/arm/mps2_an385/mps2_an385.dts

CMSIS: https://github.com/ARMmbed/mbed-os/tree/master/targets/TARGET_ARM_FM/TARGET_FVP_MPS2/TARGET_FVP_MPS2_M3/device

• CMSDK_CM3.h: https://github.com/ARMmbed/mbed-os/blob/master/targets/TARGET_ARM_SSG/TARGET_MPS2/TARGET_MPS2_M3/device/CMSDK_CM3.h
• Drivers: https://github.com/ARMmbed/mbed-os/tree/master/targets/TARGET_ARM_FM/TARGET_FVP_MPS2

Specs:

• 4MB Flash
• 4MB SRAM

Ethernet Driver - smsc911x :

• Driver implementation
  • Zephyr RTOS: https://github.com/zephyrproject-rtos/zephyr/blob/main/drivers/ethernet/eth_smsc911x.c
  • Linux: https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/smsc/smsc911x.c
  • mbedOS: https://github.com/ARMmbed/mbed-os/blob/master/targets/TARGET_ARM_FM/TARGET_FVP_MPS2/drivers/lan91c111.c
    • https://github.com/ARMmbed/mbed-os/blob/master/targets/TARGET_ARM_FM/TARGET_FVP_MPS2/drivers/lan91c111.h
  • QEMU driver emulation: https://github.com/qemu/qemu/blob/master/hw/net/smc91c111.c
• Micrium implementation: uC-TCP-IP/Dev/Ether/LAN911x

Other supported mps2 boards:

[lucas@fedora uc-os3-qemu-arm-demo]$ qemu-system-arm -machine help | grep mps
mps2-an385           ARM MPS2 with AN385 FPGA image for Cortex-M3
mps2-an386           ARM MPS2 with AN386 FPGA image for Cortex-M4
mps2-an500           ARM MPS2 with AN500 FPGA image for Cortex-M7
mps2-an505           ARM MPS2 with AN505 FPGA image for Cortex-M33
mps2-an511           ARM MPS2 with AN511 DesignStart FPGA image for Cortex-M3
mps2-an521           ARM MPS2 with AN521 FPGA image for dual Cortex-M33
mps3-an524           ARM MPS3 with AN524 FPGA image for dual Cortex-M33
mps3-an547           ARM MPS3 with AN547 FPGA image for Cortex-M55

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Ethernet driver - SMSC LAN911x

Micrium supports the SMSC (now Microship) LAN911x Ethernet controller, partially implemented in QEMU.

Known limitations (version 7.0.0 of QEMU with current Micrium stack):

• TSFL interrupt flag is not handled in QEMU, so a patch is needed for it (TODO)
  • (REQUIRED) A temporary workaround is to always check FIFO status registers. Check function NetDev_ISR_Handler of uC-TCP-IP/Dev/Ether/LAN911x/net_dev_lan911x.c

Also, additionnal points should be noted for micrium driver uC-TCP-IP/Dev/Ether/LAN911x/net_dev_lan911x.c :

• (REQUIRED) Moreover Zephyr RTOS driver sets INT_CFG_IRQ_POL bit of LAN91_INT_CFG.
• (OPTIONNAL) Zephyr RTOS driver uses 220us of interrupt deassertion interval

    reg_val  =  LAN91_INT_CFG;
    reg_val |= (22 << 24)       |
                INT_CFG_IRQ_EN  |
                INT_CFG_IRQ_POL |
                INT_CFG_IRQ_TYPE;
    LAN91_INT_CFG = reg_val;

• TODO: Some UDP packets still fail to be send (because of pending operation).
  • Check line 7312 of uC-TCP-IP/IF/net_if.c : NetIF_DevTxRdyWait(p_if, p_err);