The use of ARMv8.3 pointer authentication (PAuth) is governed by fields
in HCR_EL2, which trigger a 'trap to EL2' if not enabled. The reset
value of these fields is 'architecturally unknown' so we must ensure
that the fields are enabled (to disable the traps) if we are entering
the kernel at EL1.
The APK field disables PAuth instruction traps and the API field
disables PAuth register traps
Add code to disable the traps in armv8_switch_to_el1_m. Prior to doing
so, it checks fields in the ID_AA64ISAR1_EL1 register to ensure pointer
authentication is supported by the hardware.
The runtime checks require a second temporary register, so add this to
the EL1 transition macro signature and update 2 call sites.
Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
There are two issues:
(1) The spin table doesn't convert the endianness of the jump address.
Although there is code for it, the result isn't used at all (x0).
(2) If something goes wrong, the function returns. But that doesn't
make sense at all.
Use the actual converted jump address as destination to fix. If
there is an error, jump to a trap loop. And rearrange the code exception
level switching code to make it smaller and clearer.
This reduces the size of the spin table code section from 696 bytes to
424 bytes. If CONFIG_ARMV8_SWITCH_TO_EL1 the code size reduced from 696
bytes to 632 bytes.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
Add a new variable secondary_boot_code_start, which holds a pointer to
the start of the spin table code. This will help to relocate the code
section. While at it, move the size variable from the end to the
beginning so there is a common section for the variables. Remove any
other symbols.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
Now that the spin table is in a separate module, this is no longer
necessary. Drop it.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
Fix the alignment so it will match the comments. The spin table has to
be 8 byte aligned, so ".align 3" is enough.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
Don't use LDR to load a pointer to a function. This will generate a
literal which cannot be relocated. Use ADR which is PC-relative and
therefore can easily be relocated.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
Move it out of lowlevel.S into spintable.S. On layerscape, the secondary
CPUs are brought up in main u-boot. This will make it possible to only
compile the spin table code for the main u-boot and omit it in SPL.
This saves about 720 bytes in the SPL.
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
