| Message ID | 20240606133628.3330423-3-luca.fancellu@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add Armv8-R AArch64 support | expand |
On Thu, 6 Jun 2024 14:36:23 +0100 Luca Fancellu <luca.fancellu@arm.com> wrote: Hi, > Store the value of the initial SPSR into a variable during > EL3 initialization and load it from the variable before dropping > EL, this is done as preparation work to be able to boot from a > different exception level. > > Signed-off-by: Luca Fancellu <luca.fancellu@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Cheers, Andre > --- > arch/aarch64/boot.S | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S > index 7727475925c1..211077af17c8 100644 > --- a/arch/aarch64/boot.S > +++ b/arch/aarch64/boot.S > @@ -51,6 +51,10 @@ reset_at_el3: > b.eq err_invalid_id > bl setup_stack > > + mov w0, #SPSR_KERNEL > + ldr x1, =spsr_to_elx > + str w0, [x1] > + > bl cpu_init_bootwrapper > > bl cpu_init_el3 > @@ -135,7 +139,7 @@ ASM_FUNC(jump_kernel) > b.eq 1f > br x19 // Keep EL > > -1: mov x4, #SPSR_KERNEL > +1: ldr w4, spsr_to_elx > > /* > * If bit 0 of the kernel address is set, we're entering in AArch32 > @@ -153,3 +157,5 @@ ASM_FUNC(jump_kernel) > .align 3 > flag_keep_el: > .long 0 > +spsr_to_elx: > + .long 0
diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S index 7727475925c1..211077af17c8 100644 --- a/arch/aarch64/boot.S +++ b/arch/aarch64/boot.S @@ -51,6 +51,10 @@ reset_at_el3: b.eq err_invalid_id bl setup_stack + mov w0, #SPSR_KERNEL + ldr x1, =spsr_to_elx + str w0, [x1] + bl cpu_init_bootwrapper bl cpu_init_el3 @@ -135,7 +139,7 @@ ASM_FUNC(jump_kernel) b.eq 1f br x19 // Keep EL -1: mov x4, #SPSR_KERNEL +1: ldr w4, spsr_to_elx /* * If bit 0 of the kernel address is set, we're entering in AArch32 @@ -153,3 +157,5 @@ ASM_FUNC(jump_kernel) .align 3 flag_keep_el: .long 0 +spsr_to_elx: + .long 0
Store the value of the initial SPSR into a variable during EL3 initialization and load it from the variable before dropping EL, this is done as preparation work to be able to boot from a different exception level. Signed-off-by: Luca Fancellu <luca.fancellu@arm.com> --- arch/aarch64/boot.S | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)