Writing to UART mapped memory address

[Stefan Kalkowski]

On 07/04/2017 08:28 PM, rijurekha at ...71... wrote:
> Thanks Stefan. You are already helping a lot, so I don't want to actually
> debug code.
> 
> We could do instruction emulation for a large class of peripherals mapped
> to CSU (for example USB), but not all.
> 
> For the ones that we couln't, the issue is we cannot access the
> corresponding peripheral addresses in tz_vmm. We get a data abort at the
> following printf in the Vm_base constructor, which is called from
> 
> static Vm vm("linux" .... in main() at
> repos/os/src/server/tz_vmm/spec/imx53/main.cc.
> 
> So this is before copying linux kernel and everything else in
> repos/os/src/server/tz_vmm/include/vm_base.h.
> 
> (1) _ram_iomem_peripheral(peripheral_base, peripheral_size)
> (2) _ram_peripheral(peripheral_base, peripheral_size,
> (Genode::addr_t)Genode::env()->rm_session()->attach(_ram_iomem_peripheral.dataspace()))
> (3) Genode::printf("_ram_peripheral.local() contains %08x\n",*(unsigned
> int*)(_ram_peripheral.local()))
> 
> The following are the peripherals, with peripheral_base and
> peripheral_size, that have this behavior, along with their CSL mappings.
> CSL are all set to UNSECURE i.e. 0xff, so everything should be accessible.
> The other 50+ peripherals work fine and print the values held in those
> peripheral memory addresses in the printf mentioned above.
> ===========================================================================
> (1) write<Csl26::Slave_a>(Csl00::UNSECURE); UART3, 5000C000,3FFF
> (2) write<Csl27::Slave_a>(Csl00::UNSECURE); ESAI, 50018000, 3FFF
> (3) write<Csl02::Slave_b>(Csl00::UNSECURE); KPP, 53F94000, 3FFF
> (4) write<Csl03::Slave_a>(Csl00::UNSECURE); WDOG1, 53F98000,3FFF
> (5) write<Csl03::Slave_b>(Csl00::UNSECURE); WDOG2, 53F9C000,3FFF
> (6) write<Csl07::Slave_b>(Csl00::UNSECURE); UART1, 53FBC000, 3FFF
> (7) write<Csl08::Slave_a>(Csl00::UNSECURE); UART2, 53FC0000, 3FFF
> (8) write<Csl05::Slave_b>(Csl00::UNSECURE); CAN1, 53FC8000, 3FFF
> (9) write<Csl06::Slave_a>(Csl00::UNSECURE); CAN2, 53FCC000, 3FFF
> (10) write<Csl09::Slave_b>(Csl00::UNSECURE); CAN2, 53FCC000, 3FFF
> (11) write<Csl30::Slave_b>(Csl00::UNSECURE); UART4,  53FF0000, 3FFF
> (12) write<Csl19::Slave_a>(Csl00::UNSECURE); UART5, 63F90000, 3FFF
> (13) write<Csl16::Slave_a>(Csl00::UNSECURE); ROMCP, 63FB8000, 3FFF
> (14) write<Csl17::Slave_b>(Csl00::UNSECURE); I2C2, 63FC4000, 3FFF
> (15) write<Csl18::Slave_a>(Csl00::UNSECURE); I2C1, 63FC8000, 3FFF
> (16) write<Csl23::Slave_b>(Csl00::UNSECURE); SAHARA, 63FF8000, 3FFF
> (17) write<Csl11::Slave_b>(Csl00::UNSECURE); AHBMAX/PL301_2x2/PL301_4x1,
> 63F94000, 3FFF, 63FDC000, 3FFF, 63FE0000, 3FFF (only AHBMAX)
> (18) write<Csl09::Slave_a>(Csl00::UNSECURE); CCM/SRC/GPC/DPLLIP1-4/OWIRE,
> 53FD4000, 3FFF, 53FD0000, 3FFF, 53FD8000, 3FFF, 63F80000, 3FFF, 63F84000,
> 3FFF, 63F88000, 3FFF, 63F8C000, 3FFF, 63FA4000, 3FFF (only OWIRE gives
> secure world abort)
> ===========================================================================
> 
> The other 50+ peripherals also work fine if we make CSL for that
> peripheral secure (0x33), access that memory in linux, trap data abort to
> monitor, come to tz_vmm, get the instruction from ip, decode it and do the
> LDR/STR from the DFAR into the necessary _state->register and set
> ip->ip+4.
> 
> Have these peripherals like UART, I2C, WDOG, SAHARA, CAN etc. been
> specially set up in any way, that tz_vmm (secure world user mode) cannot
> access them? Do these peripherals have anything in common?

They are not setup specially in Genode, and I do not see what they have
in common.

Regards
Stefan

> 
> Thanks!
> Riju
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> genode-main mailing list
> genode-main at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/genode-main
> 

-- 
Stefan Kalkowski
Genode Labs

https://github.com/skalk · http://genode.org/