RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 07:27:45 +00:00
Code Issues Activity Actions

Kernel/aarch64: Execute kernel with SP_EL1 instead of SP_EL0

Browse source 
Until now the kernel was always executing with SP_EL0, as this made the
initial dropping to EL1 a bit easier. This commit changes this behaviour
to use the corresponding SP_ELx for each exception level.

To make sure that the execution of the C++ code can continue, the
current stack pointer is copied into the corresponding SP_ELx just
before dropping an exception level.
This commit is contained in:
Timon Kruiper 2023-01-08 14:01:31 +01:00 • committed by Andreas Kling
parent 05659debd1
commit 247109cee6
5 changed files with 23 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

12
Kernel/Arch/aarch64/ASM_wrapper.h
View file

@ -75,7 +75,11 @@ inline void load_el1_vector_table(void* vector_table)
inline void enter_el2_from_el3()
{
asm volatile(" adr x0, entered_el2\n"
// NOTE: This also copies the current stack pointer into SP_EL2, as
// the processor is set up to use SP_EL2 when jumping into EL2.
asm volatile(" mov x0, sp\n"
" msr sp_el2, x0\n"
" adr x0, entered_el2\n"
" msr elr_el3, x0\n"
" eret\n"
"entered_el2:" ::
@ -84,7 +88,11 @@ inline void enter_el2_from_el3()
inline void enter_el1_from_el2()
{
asm volatile(" adr x0, entered_el1\n"
// NOTE: This also copies the current stack pointer into SP_EL1, as
// the processor is set up to use SP_EL1 when jumping into EL1.
asm volatile(" mov x0, sp\n"
" msr sp_el1, x0\n"
" adr x0, entered_el1\n"
" msr elr_el2, x0\n"
" eret\n"
"entered_el1:" ::