From 14b109ea24dc5cb1db948de57a2a44c80ef4622e Mon Sep 17 00:00:00 2001
From: Brett Weiland <brett_weiland@bpcspace.com>
Date: Wed, 24 Mar 2021 15:36:54 -0500
Subject: 	modified:   README.md 	modified:  
 compiler/create_crosscompiler.sh 	deleted:    notes 	modified:  
 src/.gdb_history 	deleted:    src/amd64_vol2.pdf 	modified:  
 src/bootloader/bios_functions/bios_disk.asm 	modified:  
 src/bootloader/bios_functions/print.asm 	modified:  
 src/bootloader/bootloader.asm 	modified:   src/bootloader/cpu_check.asm 
 modified:   src/bootloader/enter_kernel.asm 	deleted:   
 src/bootloader/enter_kernel_backup 	modified:   src/bootloader/gdt.asm 
 deleted:    src/bootloader/multicore.asm 	deleted:   
 src/bootloader/notes 	new file:   src/debug/gdbinit.gdb 	deleted:   
 src/indigo_os 	modified:   src/kernel/include/libc.h 	modified:  
 src/kernel/include/paging.h 	modified:   src/kernel/include/video.h 
 modified:   src/kernel/kernel.c 	modified:   src/kernel/libs/acpi.c 
 modified:   src/kernel/libs/drivers/serial.c 	modified:  
 src/kernel/libs/drivers/video.c 	modified:   src/kernel/libs/libc.c 
 modified:   src/kernel/libs/page.c 	modified:   src/link.ld 
 modified:   src/makefile 	new file:   tools/README.md 	modified:  
 tools/page/page.py

---
 src/bootloader/cpu_check.asm | 51 +++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 19 deletions(-)

(limited to 'src/bootloader/cpu_check.asm')

diff --git a/src/bootloader/cpu_check.asm b/src/bootloader/cpu_check.asm
index ffdd908..0fa6ddf 100644
--- a/src/bootloader/cpu_check.asm
+++ b/src/bootloader/cpu_check.asm
@@ -1,38 +1,41 @@
-; TODO move this file to something like "system_check", now that we do ram checks here
 [extern _meminfo_loc]
 detect_arch:
-; todo: figure out how to just handle invalid opcode exceptions, it would be faster and (maybe?) easier 
-; todo: digest this part a little better when it's _not_ 1am.
-pushfd    ; pushes eflags to stack
-pushfd    ; pushes eflags to stack a second time
-xor dword [esp], 0x00200000 ; inverses the ID bit to see if cpuid is a thing
-pop eax         ;gets our modified cpuid back
-xor eax, [esp]  ; checks with the first time we pushed it; the OG eflag
-popfd           ; pops the flags back I guess?
-and eax, 0x00200000 ; checks to see if the bit was inverted
+
+; detect CPUID
+
+pushfd    
+pushfd    
+xor dword [esp], 0x00200000 
+pop eax         
+xor eax, [esp]  
+popfd           
+and eax, 0x00200000 
 jz .print_cpuid_error
-;now we detect if we support long slong (aka 64 bit)
 
-;https://www.amd.com/system/files/TechDocs/25481.pdf page 21
-;So apperently some dumbass engineers thought it would be funny to sell CPUs that have the long mode bit set without it being supported, dispite including it in their own documentation.
-;there's a work around by checking other bits, and it's a low priority TODO. However, I really think us coming accross this will be extremely rare.
+; detect long mode
+
 mov eax, 0x80000001
-cpuid ;cpuid returns into edx
-and edx, 0x0020000000 ; the 21st bit is cpuid.
+cpuid 
+and edx, 0x0020000000 
 jz .print_long_error
 
+; APIC
 mov eax, 0x00000001
 cpuid
-and edx, 0x00000200
+test edx, 0x00000200
 jz .print_apic_error
 
+; SSE (you might be able to remove this, I think it's a standard requirement)
+test edx, 0x2000000
+jz .print_sse_error
+
 
 mov bx, .no_error
 mov cx, 0
 call bios_print
 
 
-;mapping memory
+; get memory mappings 
 mov ax, 0
 mov es, ax
 mov ax, _meminfo_loc
@@ -71,7 +74,7 @@ call bios_print
 jmp $
 
 .print_long_error:
-mov bx, .arch_error ; lets just test for now
+mov bx, .arch_error
 mov cx, 0
 call bios_print
 jmp $
@@ -80,11 +83,19 @@ jmp $
 mov bx, .apic_error
 mov cx, 0
 call bios_print
+jmp $
 
 .print_mem_error:
 mov bx, .mem_error
 mov cx, 0
 call bios_print
+jmp $
+
+.print_sse_error:
+mov bx, .sse_error
+mov cx, 0
+call bios_print
+jmp $
 
 
 .cpuid_error:
@@ -95,6 +106,8 @@ call bios_print
   db "No apic support", 0x0
 .mem_error:
   db "Could not get information on memory!", 0x0
+.sse_error:
+  db "This OS requires SSE", 0x0
 .no_error:
   db "CPU info gathered!", 0x0
 
-- 
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