Hi all, I tried to run seL4 test suite on my ARM Cortex-A7 target board. There is no error message when boot up seL4 kernel and boot strap test program on seL4 user land. But I got a “data abort” message after call sel4utils_map_page(..vaddr) and do memset(vaddr, 0, PAGE_SIZE_4K);
There are some debug information list below.
<1> I add debug message before the program that happen data abort diff --git a/libsel4utils/src/vspace/bootstrap.c b/libsel4utils/src/vspace/bootstrap.c index c366a35..70d378a 100644 --- a/libsel4utils/src/vspace/bootstrap.c +++ b/libsel4utils/src/vspace/bootstrap.c @@ -107,13 +107,13 @@ static void *alloc_and_map(vspace_t *vspace, size_t size) {
error = sel4utils_map_page(data->vka, data->vspace_root, frame.cptr, vaddr, seL4_AllRights, 1, objects, &num); + LOG_ERROR("my-hacker\n"); if (error) { vka_free_object(data->vka, &frame); LOG_ERROR("Failed to map bootstrap frame at %p, error: %d", vaddr, error); return NULL; } + LOG_ERROR("my-hacker alloc_and_map() before memset vaddr=0x%x\n",vaddr); /* Zero the memory */ memset(vaddr, 0, PAGE_SIZE_4K);
<2>Printed messages:
ELF-loader started on CPU: ARM Ltd. Cortex-A7 r0p5 paddr=[20000000..2051881f] ELF-loading image 'kernel' paddr=[22000000..22032fff] vaddr=[e0000000..e0032fff] virt_entry=e0000000 ELF-loading image 'sel4test-driver' paddr=[22033000..22463fff] vaddr=[8000..438fff] virt_entry=15f50 Enabling MMU and paging Jumping to kernel-image entry point...
Bootstrapping kernel Booting all finished, dropped to user space Warning: using printf before serial is set up. This only works as your printf is backed by seL4_Debug_PutChar() alloc_and_map@bootstrap.c:111 my-hacker alloc_and_map@bootstrap.c:119 my-hacker alloc_and_map() before memset() vaddr=0xdf7fe000
<3>When happen data abort, the value of CPU registers: r1:0 r3:0xdf7fe000 lr:0xcbe8
<4>Objdump sel4test-driver. 0000cbc8 <memset>: cbc8: e3520000 cmp r2, #0 cbcc: e92d4030 push {r4, r5, lr} cbd0: 08bd8030 popeq {r4, r5, pc} cbd4: e0803002 add r3, r0, r2 cbd8: e6ef1071 uxtb r1, r1 cbdc: e3520002 cmp r2, #2 cbe0: e5431001 strb r1, [r3, #-1] cbe4: e5c01000 strb r1, [r0] cbe8: 98bd8030 popls {r4, r5, pc} cbec: e3520006 cmp r2, #6 It seems to write virtual address 0xdf7ff000.
<5>The virtual address 0xdf7fe000 is not map in page table
It seems sel4utils_map_page() not create page table for user land program correctly. Can anyone help me, how to solve this problem? Thanks!
Joyce Peng(彭美僑)