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| author | Wojtek Kosior <kwojtus@protonmail.com> | 2019-12-31 18:54:28 +0100 |
|---|---|---|
| committer | Wojtek Kosior <kwojtus@protonmail.com> | 2019-12-31 18:54:28 +0100 |
| commit | 0ec2016f80ffb5971362559b98b10744bb5bf893 (patch) | |
| tree | 839991c83c04ef157cdc4b3d747a79ca5975445b | |
| parent | 97612feede34cdd0099d72d0e6fa125dd65b5e9a (diff) | |
| download | rpi-MMU-example-0ec2016f80ffb5971362559b98b10744bb5bf893.tar.gz rpi-MMU-example-0ec2016f80ffb5971362559b98b10744bb5bf893.zip | |
split stack into irq, fiq and supervisor stacks; add proper handling of those in interrupt handlers (asm code)
| -rw-r--r-- | interrupt_vector.S | 25 | ||||
| -rw-r--r-- | kernel_stage2.ld | 22 | ||||
| -rw-r--r-- | memory.h | 18 |
3 files changed, 48 insertions, 17 deletions
diff --git a/interrupt_vector.S b/interrupt_vector.S index 88b32bf..af80eec 100644 --- a/interrupt_vector.S +++ b/interrupt_vector.S @@ -9,39 +9,42 @@ _interrupt_vectors: b fiq_handler_caller reset_handler_caller: - ldr sp, =_stack_top + ldr sp, =_supervisor_stack_top ldr r5, =reset_handler bx r5 undef_handler_caller: - ldr sp, =_stack_top + ldr sp, =_supervisor_stack_top ldr r5, =undefined_instruction_vector bx r5 svc_handler_caller: - ldr sp, =_stack_top + ldr sp, =_supervisor_stack_top + push {r5, lr} ldr r5, =supervisor_call_handler - push {lr} blx r5 - ldm sp!, {pc} ^ + ldm sp!, {r5, pc} ^ abort_handler_caller: - ldr sp, =_stack_top + ldr sp, =_supervisor_stack_top ldr r5, =abort_handler bx r5 generic_handler_caller: - ldr sp, =_stack_top + ldr sp, =_supervisor_stack_top ldr r5, =generic_handler bx r5 irq_handler_caller: - ldr sp, =_stack_top - ldr r5, =irq_handler - bx r5 + ldr sp, =_irq_stack_top + sub lr, #4 + push {r0-r3, lr} + ldr r3, =irq_handler + blx r3 + ldm sp!, {r0-r3, pc} ^ fiq_handler_caller: - ldr sp, =_stack_top + ldr sp, =_fiq_stack_top ldr r5, =fiq_handler bx r5 diff --git a/kernel_stage2.ld b/kernel_stage2.ld index a3df063..15b61ec 100644 --- a/kernel_stage2.ld +++ b/kernel_stage2.ld @@ -56,8 +56,24 @@ SECTIONS { _stack_start = .; - . = . + MMU_SECTION_SIZE; - - _stack_top = .; + _fiq_stack_start = .; + + . = . + (1 << 18); + + _fiq_stack_top = .; + + _irq_stack_start = .; + + . = . + (1 << 18); + + _irq_stack_top = .; + + _supervisor_stack_start = .; + + . = . + (1 << 19); + + _supervisor_stack_top = .; + + _stack_end = .; } } @@ -28,7 +28,13 @@ extern char _translation_table_end; extern char _sections_list_start; extern char _sections_list_end; extern char _stack_start; -extern char _stack_top; +extern char _fiq_stack_start; +extern char _fiq_stack_top; +extern char _irq_stack_start; +extern char _irq_stack_top; +extern char _supervisor_stack_start; +extern char _supervisor_stack_top; +extern char _stack_end; #define KERNEL_START ((size_t) &__start) // this is 0x0 #define KERNEL_END ((size_t) &__end) @@ -43,8 +49,14 @@ extern char _stack_top; // first section after the translation table is left unused; // the next section is used as the stack -#define STACK_START ((size_t) &_stack_start) -#define STACK_END ((size_t) &_stack_top) +#define STACK_START ((size_t) &_stack_start) +#define FIQ_STACK_START ((size_t) &_fiq_stack_start) +#define FIQ_STACK_END ((size_t) &_fiq_stack_top) +#define IRQ_STACK_START ((size_t) &_irq_stack_start) +#define IRQ_STACK_END ((size_t) &_irq_stack_top) +#define SUPERVISOR_STACK_START ((size_t) &_supervisor_stack_start) +#define SUPERVISOR_STACK_END ((size_t) &_supervisor_stack_top) +#define STACK_END ((size_t) &_stack_end) #define PRIVILEGED_MEMORY_END STACK_END |