Hi Wladislav, If the fault occurs before the activation of the kernel PD, this likely means that you are trying to printf before the UART is mapped.
If you are using printf for debugging before the PD is activated, you will need to change your kernel UART driver to use the physical address of the peripheral (the elfloader sets up unity mappings for 0x00000000-0xe0000000). A trick that I use to overcome this problem is to introduce a global variable that reflects the status of the PD. The UART driver then switches between the physical and virtual address of the UART as required. - Alex On Tue, 2017-01-24 at 23:55 +0100, Wladislav Wiebe wrote: > Hi Alex, > > thanks for pointing that out - I will double check the device mapping. > > - Wladislav Wiebe > > 2017-01-24 23:24 GMT+01:00 <[email protected]>: > > A "Synchronous Data abort" occurs when a virtual memory translation > > fails on load/store operations. > > A "Prefetch abort" occurs when a virtual memory translation fails when > > loading instructions into the CPU pipeline. > > An "Asynchronous Data abort" occurs when a physical memory translation > > fails (ie, no RAM or peripheral is mapped to the physical address) > > > > The address of the fault corresponds to a kernel device mapping. My > > guess is that you are not mapping kernel devices correctly at boot time: > > https://github.com/seL4/seL4/blob/master/include/plat/exynos5/plat/machine/devices.h#L15 > > https://github.com/seL4/seL4/blob/master/include/plat/exynos5/plat/machine/hardware.h#L26 > > https://github.com/seL4/seL4/blob/master/src/arch/arm/32/machine/hardware.c#L51 > > > > > > - Alex > > > > On Tue, 2017-01-24 at 17:17 +0100, Wladislav Wiebe wrote: > >> could it be an TLB fault? For my understandig, based on > >> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0438g/BABFFDFD.html > >> it is the DFSR = 0x7 -> b00111 > >> Translation fault, 2nd level. > >> > >> > >> Thanks! > >> - Wladislav Wiebe > >> > >> 2017-01-24 15:42 GMT+01:00 Wladislav Wiebe <[email protected]>: > >> > Hello, > >> > > >> > has somebody experience with running into arm_data_abort_exception > >> > after enabling the MMU/paging and jumping to the kernel image: > >> > .. > >> > ELF-loader started on CPU: ARM Ltd. Cortex-A15 r2p4 > >> > paddr=[90000000..904b041f] > >> > ELF-loading image 'kernel' > >> > paddr=[80000000..80033fff] > >> > vaddr=[f0000000..f0033fff] > >> > virt_entry=f0000000 > >> > ELF-loading image 'sel4test-driver' > >> > paddr=[80034000..8042dfff] > >> > vaddr=[10000..409fff] > >> > virt_entry=1e924 > >> > Enabling MMU and paging > >> > Jumping to kernel-image entry point... > >> > > >> > check_data_abort_exception() > >> > DFAR = 0xfff01014 > >> > DFSR = 0x7 > >> > ADFSR = 0x0 > >> > abort() called. > >> > > >> > I've dumped the DFAR/DFSR register -- > >> > > >> > Relevant config parts about the setup: > >> > CONFIG_ARCH_ARM_V7A=y > >> > CONFIG_ARCH_ARM=y > >> > CONFIG_ARCH_AARCH32=y > >> > CONFIG_ARM_CORTEX_A15=y > >> > CONFIG_PLAT_KEYSTONE=y > >> > > >> > > >> > Thanks in advance! > >> > -- > >> > WBR, Wladislav WIebe > >> > >> > >> > > > > > _______________________________________________ Devel mailing list [email protected] https://sel4.systems/lists/listinfo/devel
