There are many instances in ARM Trusted Firmware where control is
transferred to functions from which return isn't expected. Such jumps
are made using 'bl' instruction to provide the callee with the location
from which it was jumped to. Additionally, debuggers infer the caller by
examining where 'lr' register points to. If a 'bl' of the nature
described above falls at the end of an assembly function, 'lr' will be
left pointing to a location outside of the function range. This misleads
the debugger back trace.
This patch defines a 'no_ret' macro to be used when jumping to functions
from which return isn't expected. The macro ensures to use 'bl'
instruction for the jump, and also, for debug builds, places a 'nop'
instruction immediately thereafter (unless instructed otherwise) so as
to leave 'lr' pointing within the function range.
Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
In order to avoid unexpected traps into EL3/MON mode, this patch
resets the debug registers, MDCR_EL3 and MDCR_EL2 for AArch64,
and SDCR and HDCR for AArch32.
MDCR_EL3/SDCR is zero'ed when EL3/MON mode is entered, at the
start of BL1 and BL31/SMP_MIN.
For MDCR_EL2/HDCR, this patch zero's the bits that are
architecturally UNKNOWN values on reset. This is done when
exiting from EL3/MON mode but only on platforms that support
EL2/HYP mode but choose to exit to EL1/SVC mode.
FixesARM-software/tf-issues#430
Change-Id: Idb992232163c072faa08892251b5626ae4c3a5b6
Signed-off-by: David Cunado <david.cunado@arm.com>
At present the `el3_entrypoint_common` macro uses `memcpy`
function defined in lib/stdlib/mem.c file, to copy data
from ROM to RAM for BL1. Depending on the compiler being
used the stack could potentially be used, in `memcpy`,
for storing the local variables. Since the stack is
initialized much later in `el3_entrypoint_common` it
may result in unknown behaviour.
This patch adds `memcpy4` function definition in assembly so
that it can be used before the stack is initialized and it
also replaces `memcpy` by `memcpy4` in `el3_entrypoint_common`
macro, to copy data from ROM to RAM for BL1.
Change-Id: I3357a0e8095f05f71bbbf0b185585d9499bfd5e0
This patch adds common changes to support AArch32 state in
BL1 and BL2. Following are the changes:
* Added functions for disabling MMU from Secure state.
* Added AArch32 specific SMC function.
* Added semihosting support.
* Added reporting of unhandled exceptions.
* Added uniprocessor stack support.
* Added `el3_entrypoint_common` macro that can be
shared by BL1 and BL32 (SP_MIN) BL stages. The
`el3_entrypoint_common` is similar to the AArch64
counterpart with the main difference in the assembly
instructions and the registers that are relevant to
AArch32 execution state.
* Enabled `LOAD_IMAGE_V2` flag in Makefile for
`ARCH=aarch32` and added check to make sure that
platform has not overridden to disable it.
Change-Id: I33c6d8dfefb2e5d142fdfd06a0f4a7332962e1a3
