From 93bf62580a68533dc8252b9a2a055c02f34ecb67 Mon Sep 17 00:00:00 2001 From: Christian Cunningham Date: Thu, 24 Mar 2022 09:38:08 -0700 Subject: Modularized --- kernel/boot.S | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 kernel/boot.S (limited to 'kernel/boot.S') diff --git a/kernel/boot.S b/kernel/boot.S new file mode 100644 index 0000000..46ef3d0 --- /dev/null +++ b/kernel/boot.S @@ -0,0 +1,118 @@ +// To keep this in the first portion of the binary. +.section ".text.boot" + +// Make _start global. +.globl _start + +.include "macros.inc" + +_start: +reset: + cpsid aif + + // Exit Hypervisor Mode + mrs r0, cpsr + and r1, r0, #0x1F + cmp r1, #0x1A + bne 1f + bic r0, r0, #0x1f + orr r0, r0, #0x13 + msr spsr_cxsf, r0 + add r0, pc, #4 + msr ELR_hyp, r0 + eret + +1: + // disable core0,1,2. + mrc p15, #0, r1, c0, c0, #5 + and r1, r1, #3 + cmp r1, #1 + beq runcore1 + cmp r1, #2 + beq runcore2 + cmp r1, #3 + bge runcore3 + + init_core 0 + + // Clear out bss. + ldr r4, =__bss_start + ldr r9, =__bss_end + mov r5, #0 + mov r6, #0 + mov r7, #0 + mov r8, #0 + b 2f + +1: // store multiple at r4. + stmia r4!, {r5-r8} + +2: // If we are still below bss_end, loop. + cmp r4, r9 + blo 1b + + // Clear mailboxes + mov r4, #0 + ldr r5, =mbox_core0 + str r4, [r5] + ldr r5, =mbox_core1 + str r4, [r5] + ldr r5, =mbox_core2 + str r4, [r5] + ldr r5, =mbox_core3 + str r4, [r5] + + // Call kernel_main + ldr r3, =kernel_main + blx r3 + +runcore1: + init_core 1 + b io_halt +runcore2: + init_core 2 + b io_halt +runcore3: + init_core 3 + b io_halt + +.globl io_halt +io_halt: + wfi + b io_halt + +.align 5 +vector: + ldr pc, reset_handler + ldr pc, undefined_handler + ldr pc, svc_handler + ldr pc, prefetch_handler + ldr pc, data_handler + ldr pc, unused_handler + ldr pc, irq_handler + ldr pc, fiq_handler + +reset_handler: .word reset +undefined_handler: .word undefined +svc_handler: .word svc +prefetch_handler: .word prefetch +data_handler: .word data +unused_handler: .word io_halt +irq_handler: .word irq +fiq_handler: .word fiq + +.section .data +.globl mbox_core0 +mbox_core0: .word 0 +.globl mbox_core1 +mbox_core1: .word 0 +.globl mbox_core2 +mbox_core2: .word 0 +.globl mbox_core3 +mbox_core3: .word 0 + +.section .bss.estacks +core_stacks 0 +core_stacks 1 +core_stacks 2 +core_stacks 3 -- cgit v1.2.1