fox32os/kernel/main.asm
2022-05-19 14:15:40 -07:00

83 lines
1.8 KiB
NASM

; fox32os kernel
org 0x00000800
const FOX32OS_VERSION_MAJOR: 0
const FOX32OS_VERSION_MINOR: 1
const FOX32OS_VERSION_PATCH: 0
const BACKGROUND_COLOR: 0xFF674764
const TEXT_COLOR: 0xFFFFFFFF
; initialization code
entry:
; clear the background
mov r0, BACKGROUND_COLOR
call fill_background
draw_startup_text:
mov r0, startup_str
mov r1, 16
mov r2, 464
mov r3, TEXT_COLOR
mov r4, 0x00000000
mov r10, FOX32OS_VERSION_MAJOR
mov r11, FOX32OS_VERSION_MINOR
mov r12, FOX32OS_VERSION_PATCH
call draw_format_str_to_background
; open startup.cfg
mov r0, startup_file
mov r1, 0
mov r2, startup_file_struct
call ryfs_open
cmp r0, 0
ifz jmp startup_error
; load the first 11 bytes of startup.cfg, overwriting the "startup cfg" string
mov r0, 11
mov r1, startup_file_struct
mov r2, startup_file
call ryfs_read
; open the actual startup file
mov r0, startup_file
mov r1, 0
mov r2, startup_file_struct
call ryfs_open
cmp r0, 0
ifz jmp startup_error
; read the startup file into memory starting at the bottom of the kernel
mov r0, startup_file_struct
mov r1, kernel_bottom
call ryfs_read_whole_file
; relocate and execute it!!!
mov r0, kernel_bottom
call execute_fxf_binary
rjmp 0
startup_error:
mov r0, startup_error_str
mov r1, 16
mov r2, 16
mov r3, TEXT_COLOR
mov r4, 0x00000000
call draw_str_to_background
rjmp 0
#include "allocator.asm"
#include "fxf/fxf.asm"
startup_str: data.str "fox32 - OS version %u.%u.%u" data.8 0
startup_file: data.str "startup cfg"
startup_error_str: data.str "startup.cfg is invalid" data.8 0
startup_file_struct: data.32 0 data.32 0
#include "../../fox32rom/fox32rom.def"
kernel_bottom: