Hi all, For experiment, I created a simple app along with the vmm using CamKES-ARM-VM repository. Currently the simple app only prints strings periodically using printf(). However as soon as the guest Linux starting running. I cannot print anything and also receives error as following: I assumes it is due to the iommu capability got assigned to Linux by VMM. Is there a way to allow native app also prints information on the screen using printf()? ------------------ libsel4muslcsys: Error attempting syscall 162 FAULT HANDLER: data fault from hello.control (ID 0x1) on address 0xffffff80, pc = 0x135ac, fsr = 0x3840046 FAULT HANDLER: pc = 0x135ac FAULT HANDLER: sp = 0x142d20 FAULT HANDLER: lr = 0x135ac FAULT HANDLER: r0 = 0xffffff80 FAULT HANDLER: r1 = 0 FAULT HANDLER: r2 = 0 FAULT HANDLER: r3 = 0 FAULT HANDLER: r4 = 0x26 FAULT HANDLER: r5 = 0 FAULT HANDLER: r6 = 0 FAULT HANDLER: r7 = 0xfffffff2 FAULT HANDLER: r8 = 0x1 FAULT HANDLER: r9 = 0 FAULT HANDLER: r10 = 0 FAULT HANDLER: r12 = 0x142caa FAULT HANDLER: r14 = 0x135ac FAULT HANDLER: cpsr = 0x20000050 FAULT HANDLER: memory map: FAULT HANDLER: +-- 0x00143fff -- FAULT HANDLER: | guard page FAULT HANDLER: +-- 0x00143000 -- FAULT HANDLER: | stack FAULT HANDLER: +-- 0x0013f000 -- FAULT HANDLER: | guard page FAULT HANDLER: +-- 0x0013e000 -- FAULT HANDLER: | <undescribed> FAULT HANDLER: +-- 0x00137fff -- FAULT HANDLER: | guard page FAULT HANDLER: +-- 0x00137000 -- FAULT HANDLER: | IPC buffer FAULT HANDLER: +-- 0x00136000 -- FAULT HANDLER: | guard page FAULT HANDLER: +-- 0x00135000 -- FAULT HANDLER: | <undescribed> FAULT HANDLER: +-- 0x00131fff -- FAULT HANDLER: | code and data FAULT HANDLER: +-- 0x00010000 -- CPIO: 2 files found. 0) linux 0x00059c70, 16302080 bytes 1) linux-dtb 0x00fe5ce8, 29415 bytes Best Regards -Daniel Wang