mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2025-12-27 18:25:05 +00:00
3ec36e0160
This change configures MPU to prevent instruction fetch from the flash image that is not running at the time system_disable_jump is called. Violating the protection causes instruction access violation, then the EC reboots. RO image protection is tested as follows: ... [6.255696 MPU type: 00000800] [6.255874 RAM locked. Exclusion 20005680-200056a0] [6.256168 RO image locked] ... > sysjump 0 Jumping to 0x00000000 === PROCESS EXCEPTION: 03 ====== xPSR: 60000000 === r0 :00000000 r1 :2000541c r2 :00001388 r3 :20007fe8 r4 :200032f0 r5 :00000000 r6 :20002b70 r7 :20002df4 r8 :0002d308 r9 :20002df4 r10:00000000 r11:00000000 r12:00000002 sp :20002358 lr :0002a1a7 pc :00000000 Instruction access violation, Forced hard fault mmfs = 1, shcsr = 70000, hfsr = 40000000, dfsr = 0 =========== Process Stack Contents =========== 200023c0: 00000098 00000000 00000000 0002a785 200023d0: 00000002 20002dfd 00000007 20002b70 200023e0: 00000002 00025777 00000000 20002dfd 200023f0: 20002df4 20002dfc 00000000 00000000 Rebooting... Memory management fault status register has bit0 set, indicating there was an instruction fetch volation. FYI, RAM protection is still working: > sysjump 0x20000000 Jumping to 0x20000000 === PROCESS EXCEPTION: 03 ====== xPSR: 60000000 === r0 :00000000 r1 :2000541c r2 :00001388 r3 :20007fe8 r4 :200032f0 r5 :20000000 r6 :20002b70 r7 :20002df4 r8 :0002d308 r9 :20002df4 r10:00000000 r11:00000000 r12:00000002 sp :20002358 lr :0002a1a7 pc :20000000 Instruction access violation, Forced hard fault mmfs = 1, shcsr = 70000, hfsr = 40000000, dfsr = 0 =========== Process Stack Contents =========== 200023c0: 00000098 00000000 20000000 0002a785 200023d0: 00000002 20002e06 00000007 20002b70 200023e0: 00000002 00025777 00000000 20002e06 200023f0: 20002df4 20002dfc 00000000 00000000 Rebooting... TEST=Booted Peppy. Tested lid close & open. Ran Flashrom from userspace to update main firmware then software-synched an EC image. BUG=chrome-os-partner:16904 BRANCH=none Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org> Change-Id: Id4f84d24325566a9f648194166bde0d94d1124dc Reviewed-on: https://chromium-review.googlesource.com/169050 Reviewed-by: Bill Richardson <wfrichar@chromium.org> Reviewed-by: Randall Spangler <rspangler@chromium.org> Commit-Queue: Daisuke Nojiri <dnojiri@google.com> Tested-by: Daisuke Nojiri <dnojiri@google.com>