From 03fa5edfa5562f2fd3a8895d85da2cdcdbb92377 Mon Sep 17 00:00:00 2001
From: Aleksa Vuckovic <aleksav013@gmail.com>
Date: Sun, 29 Jan 2023 16:56:16 +0100
Subject: SMP WORKING

---
 kernel/src/scheduler/ap_init.S    | 71 +++++++++++++++++++++++++++++++++++++++
 kernel/src/scheduler/ap_startup.c |  5 +++
 2 files changed, 76 insertions(+)
 create mode 100644 kernel/src/scheduler/ap_init.S
 create mode 100644 kernel/src/scheduler/ap_startup.c

(limited to 'kernel/src/scheduler')

diff --git a/kernel/src/scheduler/ap_init.S b/kernel/src/scheduler/ap_init.S
new file mode 100644
index 0000000..8cb4314
--- /dev/null
+++ b/kernel/src/scheduler/ap_init.S
@@ -0,0 +1,71 @@
+.section .apinit, "a"
+
+
+.SET stack_top, 0x3008000
+.SET stack_off, 0x8000
+.SET bspdone, 0x3000100
+.SET aprunning, 0x3000200
+
+# this code will be relocated to 0x8000, sets up environment for calling a C function
+.code16
+ap_trampoline:
+	cli
+	cld
+	ljmp $0, $0x8040
+.align 16
+_L8010_GDT_table:
+	.long 0, 0
+	.long 0x0000FFFF, 0x00CF9A00 # flat code
+	.long 0x0000FFFF, 0x008F9200 # flat data
+	.long 0x00000068, 0x00CF8900 # tss
+_L8030_GDT_value:
+	.word _L8030_GDT_value - _L8010_GDT_table - 1
+	.long 0x8010
+	.long 0, 0
+	.align 64
+_L8040:
+	xorw %ax, %ax
+	movw %ax, %ds
+	lgdtl 0x8030
+	movl %cr0, %eax
+	orl $1, %eax
+	movl %eax, %cr0
+	ljmp $8, $0x8060
+	.align 32
+	.code32
+_L8060:
+	movw $16, %ax
+	movw %ax, %ds
+	movw %ax, %ss
+	# get our Local APIC ID
+	mov $1, %eax
+	cpuid
+	shrl $24, %ebx
+	movl %ebx, %edi
+
+
+	# set up 32k stack, one for each core. It is important that all core must have its own stack
+	movl $stack_top, %esp
+	mov %edi, %ecx
+2:
+	addl $stack_off, %esp
+	decl %ecx
+	cmp $0, %ecx
+	jne 2b
+
+	shll $15, %ebx
+	subl %ebx, %esp
+	pushl %edi
+	# spinlock, wait for the BSP to finish
+1:
+	pause
+	cmpb $0, bspdone
+	jz 1b
+	lock incb aprunning
+
+3:
+	hlt
+	jmp 3b
+
+	# jump into C code (should never return)
+	# ljmp $8, $ap_startup
diff --git a/kernel/src/scheduler/ap_startup.c b/kernel/src/scheduler/ap_startup.c
new file mode 100644
index 0000000..43b1a51
--- /dev/null
+++ b/kernel/src/scheduler/ap_startup.c
@@ -0,0 +1,5 @@
+// this C code can be anywhere you want it, no relocation needed
+void ap_startup(int apicid) {
+	// do what you want to do on the AP
+	while(1);
+}
-- 
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