kernel: update boot code and linker script for aarch64

Signed-off-by: EnderIce2 <enderice2@protonmail.com>

Kernel/arch/aarch64/bootstrap/boot.S

@@ -1,36 +1,49 @@
-/* Based on this tutorial:
+/*
-   https://github.com/s-matyukevich/raspberry-pi-os */
+	This file is part of Fennix Kernel.
 
-.section ".text.boot", "a"
+	Fennix Kernel is free software: you can redistribute it and/or
+	modify it under the terms of the GNU General Public License as
+	published by the Free Software Foundation, either version 3 of
+	the License, or (at your option) any later version.
 
-.extern _bss_start
+	Fennix Kernel is distributed in the hope that it will be useful,
-.extern _bss_end
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
 
-.extern arm64Entry
+	You should have received a copy of the GNU General Public License
-memzero:
+	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
-	str xzr, [x0], #8
+*/
-	subs x1, x1, #8
+
-	b.gt memzero
+.section ".bootstrap.boot", "a"
-	ret
+
+.extern _kernel_bss_start
+.extern _kernel_bss_end
+.extern _kernel_bss_size
 
 .global _start
 _start:
-	mrs x0, mpidr_el1
+	/* Keep only the main core */
-	and x0, x0, #0xFF
+	mrs x1, mpidr_el1
-	cbz x0, _start2
+	and x1, x1, #3
-	b CPU_Loop
+	cbz x1, 2f
 
-_start2:
+	/* Halt */
-	adr x0, _bss_start
+1:	wfe
-	adr x1, _bss_end
+	b 1b
-	sub x1, x1, x0
-	bl memzero
-	mov sp, #0x200000
-	bl arm64Entry
 
-Halt:
+	/* Initialize the stack */
-	wfe
+2:	ldr x1, =_start
-	b Halt
+	mov sp, x1
 
-CPU_Loop:
+	/* Clear the BSS */
-	b CPU_Loop
+	ldr x1, =_kernel_bss_start
+	ldr w2, =_kernel_bss_size
+3:	cbz w2, 4f
+	str xzr, [x1], #8
+	sub w2, w2, #1
+	cbnz w2, 3b
+
+	/* Start the kernel */
+4:	bl _aarch64_start
+	b 1b

Kernel/arch/aarch64/bootstrap/init.c

@@ -0,0 +1,24 @@
+/*
+	This file is part of Fennix Kernel.
+
+	Fennix Kernel is free software: you can redistribute it and/or
+	modify it under the terms of the GNU General Public License as
+	published by the Free Software Foundation, either version 3 of
+	the License, or (at your option) any later version.
+
+	Fennix Kernel is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <types.h>
+
+__attribute__((section(".bootstrap.text"))) void _aarch64_start(uint64_t dtb_ptr32, uint64_t x1, uint64_t x2, uint64_t x3)
+{
+	while (1)
+		;
+}

Kernel/arch/aarch64/linker.ld

@@ -20,43 +20,60 @@ OUTPUT_ARCH(aarch64)
 
 ENTRY(_start)
 
+PF_R = 0x4;
+PF_W = 0x2;
+PF_X = 0x1;
+
+PHDRS
+{
+	bootstrap   PT_LOAD    FLAGS( PF_R | PF_W /*| PF_X*/ );
+	text        PT_LOAD    FLAGS( PF_R | PF_X );
+	data        PT_LOAD    FLAGS( PF_R | PF_W );
+	rodata      PT_LOAD    FLAGS( PF_R );
+	bss         PT_LOAD    FLAGS( PF_R | PF_W );
+}
+
 SECTIONS
 {
+	. = 0x80000;
 	_bootstrap_start = .;
-	.text.boot :
+	.bootstrap :
 	{
-		*(.text.boot)
+		*(.bootstrap.boot .bootstrap.boot.*)
-		. += CONSTANT(MAXPAGESIZE);
+		*(.bootstrap .bootstrap.*)
-		_bss_start = .;
+	} :bootstrap
-		*(.text.bss)
-		_bss_end = .;
-	}
 	_bootstrap_end = .;
 
 	_kernel_start = .;
 	_kernel_text_start = .;
 	.text :
 	{
-		KEEP(*(.text.boot))
 		*(.text .text.*)
-	}
+	} :text
-	. = ALIGN(4096);
 	_kernel_text_end = .;
 
 	_kernel_data_start = .;
 	.data :
 	{
 		*(.data .data.*)
-	}
+	} :data
-	. = ALIGN(4096);
+
+	.eh_frame :
+	{
+		KEEP (*(.eh_frame .eh_frame.*))
+	} :data
+
+	.gcc_except_table :
+	{
+		KEEP (*(.gcc_except_table .gcc_except_table.*))
+	} :data
 	_kernel_data_end = .;
 
 	_kernel_rodata_start = .;
 	.rodata :
 	{
 		*(.rodata .rodata.*)
-	}
+	} :rodata
-	. = ALIGN(4096);
 
 	.init_array :
 	{
@@ -64,7 +81,7 @@ SECTIONS
 		KEEP(*(.init_array .ctors))
 		KEEP(*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))
 		PROVIDE_HIDDEN (__init_array_end = .);
-	}
+	} :rodata
 
 	.fini_array :
 	{
@@ -72,18 +89,33 @@ SECTIONS
 		KEEP(*(SORT_BY_INIT_PRIORITY(.fini_array.*) SORT_BY_INIT_PRIORITY(.dtors.*)))
 		KEEP(*(.fini_array .dtors))
 		PROVIDE_HIDDEN (__fini_array_end = .);
-	}
+	} :rodata
+
+	.eh_frame_hdr :
+	{
+		*(.eh_frame_hdr .eh_frame_hdr.*)
+	} :rodata
+
+	.eh_frame :
+	{
+		KEEP (*(.eh_frame .eh_frame.*))
+	} :rodata
+
+	.gcc_except_table :
+	{
+		KEEP (*(.gcc_except_table .gcc_except_table.*))
+	} :rodata
 	_kernel_rodata_end = .;
 
 	_kernel_bss_start = .;
 	.bss :
 	{
+		*(COMMON)
 		*(.bss .bss.*)
-	}
+	} :bss
-	. = ALIGN(4096);
 	_kernel_bss_end = .;
+	_kernel_bss_size = SIZEOF(.bss);
 	_kernel_end = .;
-	_bss_size = _kernel_end - _kernel_rodata_end;
 
 	/DISCARD/ :
 	{