Improved SWI service routine to handle C functions

This commit is contained in:
giomba 2018-12-31 17:28:04 +01:00
parent c4342f1b89
commit 52c288a056
6 changed files with 69 additions and 27 deletions

8
src/isr.cpp Normal file
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@ -0,0 +1,8 @@
#include <stdint.h>
#include <dbg.h>
extern "C" void c_swi_handler(uint32_t type) {
printk("Serving SWI # ");
printkl(itoa(type));
// TODO: to be done =)
}

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@ -2,14 +2,21 @@
#include <stdint.h>
#include <interrupt.h>
extern "C" void go_usr(void);
/* KERNEL MAIN */
extern "C" int main(int argc, char** argv) {
printkl("Welcome to STKARM -- Simple and Trivial Kernel for Advanced Reduced Instruction Set Computer Machines");
printkl("Now firing software interrupt...");
printkl("Installing kernel...");
printkl("Now firing test software interrupt...");
fireswi();
printkl("EOK -- End of Kernel -- Now returning to assembly");
printkl("Go user...");
go_usr();
printkl("EOK -- End of Kernel -- This point can not be reached");
return 0;
}

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@ -1,31 +1,29 @@
ENTRY(_start)
MEMORY {
m_text (RX) : ORIGIN = 0x40000000, LENGTH = 16M
m_data (RW) : ORIGIN = 0x41000000, LENGTH = 16M
m_stack (RW) : ORIGIN = 0x42000000, LENGTH = 16M
m_ram (RWX) : ORIGIN = 0x40000000, LENGTH = 2048M
}
SECTIONS
{
. = 0x40000000;
.text : ALIGN(0x1000) {
*(.text)
} > m_text
.data : ALIGN(0x1000) {
*(.data)
} > m_data
.bss : ALIGN(0x1000) {
*(.bss)
} > m_data
. = ALIGN(0x100); stack_svc = .;
.stack : ALIGN(0x100) {
. = . + 0x100; stack_svc = .;
. = . + 0x100; stack_und = .;
. = . + 0x100; stack_abt = .;
. = . + 0x100; stack_irq = .;
. = . + 0x100; stack_fiq = .;
. = . + 0x100; stack_sys = .;
. = . + 0x100; stack_usr = .;
. = . + 0x100; stack_sys = .; stack_usr = .;
} > m_ram
.data : ALIGN(0x4) {
*(.data)
} > m_ram
.bss : ALIGN(0x4) {
*(.bss)
} > m_ram
.text : ALIGN(0x4) {
*(.text)
} > m_ram
}

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@ -24,9 +24,8 @@ _start:
cps #0x1f
ldr sp, =stack_sys
// Leave in usr mode
// cps #0x10
// ldr sp, =stack_usr
/* Enter SuperVisor Mode */
cps #0x13
/* Enable Vector Table BAR remapping (clears bit 13 of SCTLR) */
mrc p15, 0, r0, c1, c0, 0

20
src/user.s Normal file
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@ -0,0 +1,20 @@
.global go_usr
go_usr:
mrs r0, cpsr
bl itoa
bl printkl
/* Actually go to user mode */
cps #0x10
ldr sp, =stack_usr
mrs r0, cpsr
bl itoa
bl printkl
swi #0xc
swi #0x1
swi #0xa
swi #0x0
b .

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@ -37,12 +37,22 @@ und_handler:
ldmfd sp!, {pc}^
swi_handler:
stmfd sp!, {lr}
stmfd sp!, {r0-r12, lr}
ldr r0, =swi_msg
bl printkl
/* Get SWI number to pass to c_swi_handler */
ldr r10, [lr, #-4]
and r10, #0x00ffffff
mov r0, r10
ldmfd sp!, {pc}^
mov r1, sp
mrs r2, spsr
stmfd sp!, {r2}
bl c_swi_handler
ldmfd sp!, {r2}
msr spsr_cxsf, r2
ldmfd sp!, {r0-r12, pc}^
// TODO: untested
prefetch_abt_handler: