Serial commit

Author: Ian Seyler

src/init/serial.asm

@@ -0,0 +1,65 @@
+; =============================================================================
+; Pure64 -- a 64-bit OS/software loader written in Assembly for x86-64 systems
+; Copyright (C) 2008-2025 Return Infinity -- see LICENSE.TXT
+;
+; INIT SERIAL - 115200 bps, 8N1 (8 data bits, no parity, and 1 stop bit)
+; =============================================================================
+
+
+init_serial:
+	; Disable Interrupts
+	mov dx, COM_PORT_INTERRUPT_ENABLE
+	mov al, 0			; Disable all interrupts
+	out dx, al
+
+	; Enable divisor register for setting baud rate
+	mov dx, COM_PORT_LINE_CONTROL
+	mov dl, 0x80			; DLB (7 set)
+	out dx, al
+
+	; Send the divisor (baud rate will be 115200 / divisor)
+	mov dx, COM_PORT_DATA
+	mov ax, BAUD_115200
+	out dx, al
+	mov dx, COM_PORT_DATA+1
+	shr ax, 8
+	out dx, al
+
+	; Disable divisor register and set values
+	mov dx, COM_PORT_LINE_CONTROL
+	mov al, 00000111b		; 8 data bits (0-1 set), one stop bit (2 set), no parity (3-5 clear), DLB (7 clear)
+	out dx, al
+
+	; Disable modem control
+	mov dx, COM_PORT_MODEM_CONTROL
+	mov al, 0
+	out dx, al
+
+	; Set FIFO
+	mov dx, COM_PORT_FIFO_CONTROL
+	mov al, 0xC7			; Enable FIFO, clear them, 14-byte threshold
+	out dx, al
+
+	ret
+
+
+; Port Registers
+COM_BASE			equ 0x3F8
+COM_PORT_DATA			equ COM_BASE + 0
+COM_PORT_INTERRUPT_ENABLE	equ COM_BASE + 1
+COM_PORT_FIFO_CONTROL		equ COM_BASE + 2
+COM_PORT_LINE_CONTROL		equ COM_BASE + 3
+COM_PORT_MODEM_CONTROL		equ COM_BASE + 4
+COM_PORT_LINE_STATUS		equ COM_BASE + 5
+COM_PORT_MODEM_STATUS		equ COM_BASE + 6
+COM_PORT_SCRATCH_REGISTER	equ COM_BASE + 7
+
+; Baud Rates
+BAUD_115200			equ 1
+BAUD_57600			equ 2
+BAUD_9600			equ 12
+BAUD_300			equ 384
+
+
+; =============================================================================
+; EOF

src/pure64.asm

@@ -260,6 +260,25 @@ start64:
 	mov ebx, 0
 	call debug_block
 
+	; Configure serial port @ 0x03F8 as 115200 8N1
+	call init_serial
+	
+	mov rsi, msg_pure64		; Output "[ Pure64 ]"
+	call debug_msg
+	
+	; Output boot method
+	mov rsi, msg_boot
+	call debug_msg
+	cmp byte [p_BootMode], 'U'
+	je boot_uefi
+	mov rsi, msg_bios
+	call debug_msg
+	jmp msg_boot_done
+boot_uefi:
+	mov rsi, msg_uefi
+	call debug_msg
+msg_boot_done:
+
 ; Clear out the first 20KiB of memory. This will store the 64-bit IDT, GDT, PML4, PDP Low, and PDP High
 	mov ecx, 5120
 	xor eax, eax
@@ -716,25 +735,41 @@ pde_end:
 	mov ebx, 4
 	call debug_block
 
+	mov rsi, msg_acpi
+	call debug_msg
 	call init_acpi			; Find and process the ACPI tables
+	mov rsi, msg_ok
+	call debug_msg
 
 ; Visual Debug (4/8)
 	mov ebx, 6
 	call debug_block
 
+	mov rsi, msg_bsp
+	call debug_msg
 	call init_cpu			; Configure the BSP CPU
+	mov rsi, msg_ok
+	call debug_msg
 
 ; Visual Debug (5/8)
 	mov ebx, 8
 	call debug_block
 	
+	mov rsi, msg_hpet
+	call debug_msg
 	call init_hpet			; Configure the HPET
+	mov rsi, msg_ok
+	call debug_msg
 
 ; Visual Debug (6/8)
 	mov ebx, 10
 	call debug_block
 
+	mov rsi, msg_smp
+	call debug_msg
 	call init_smp			; Init of SMP, deactivate interrupts
+	mov rsi, msg_ok
+	call debug_msg
 
 ; Reset the stack to the proper location (was set to 0x8000 previously)
 	mov rsi, [p_LocalAPICAddress]	; We would call p_smp_get_id here but the stack is not ...
@@ -887,6 +922,9 @@ lfb_wc_end:
 	mov ebx, 14
 	call debug_block
 
+	mov rsi, msg_kernel
+	call debug_msg
+
 %ifdef BIOS
 	cmp byte [p_BootDisk], 'F'	; Check if sys is booted from floppy?
 	jnz clear_regs
@@ -916,6 +954,7 @@ clear_regs:
 %include "init/acpi.asm"
 %include "init/cpu.asm"
 %include "init/hpet.asm"
+%include "init/serial.asm"
 %include "init/smp.asm"
 %ifdef BIOS
 %include "fdc/dma.asm"
@@ -1010,6 +1049,106 @@ debug_progressbar:
 %endif
 
 
+; -----------------------------------------------------------------------------
+; debug_msg_char - Send a single char via the serial port
+; IN: AL = Byte to send
+debug_msg_char:
+	pushf
+	push rdx
+	push rax			; Save the byte
+	mov dx, 0x03F8			; Address of first serial port
+debug_msg_char_wait:
+	add dx, 5			; Offset to Line Status Register
+	in al, dx
+	sub dx, 5			; Back to to base
+	and al, 0x20
+	cmp al, 0
+	je debug_msg_char_wait
+	pop rax				; Restore the byte
+	out dx, al			; Send the char to the serial port
+debug_msg_char_done:
+	pop rdx
+	popf
+	ret
+; -----------------------------------------------------------------------------
+
+
+; -----------------------------------------------------------------------------
+; debug_msg_char - Send a message via the serial port
+; IN: RSI = Location of message
+debug_msg:
+	pushf
+	push rdx
+	push rax
+	cld				; Clear the direction flag.. we want to increment through the string
+	mov dx, 0x03F8			; Address of first serial port
+debug_msg_next:
+	add dx, 5			; Offset to Line Status Register
+	in al, dx
+	sub dx, 5			; Back to to base
+	and al, 0x20
+	cmp al, 0
+	je debug_msg_next
+	lodsb				; Get char from string and store in AL
+	cmp al, 0
+	je debug_msg_done
+	out dx, al			; Send the char to the serial port
+	jmp debug_msg_next
+debug_msg_done:
+	pop rax
+	pop rdx
+	popf
+	ret
+; -----------------------------------------------------------------------------
+
+
+; -----------------------------------------------------------------------------
+; debug_dump_(rax|eax|ax|al) -- Dump content of RAX, EAX, AX, or AL
+;  IN:	RAX/EAX/AX/AL = content to dump
+; OUT:	Nothing, all registers preserved
+debug_dump_rax:
+	rol rax, 8
+	call debug_dump_al
+	rol rax, 8
+	call debug_dump_al
+	rol rax, 8
+	call debug_dump_al
+	rol rax, 8
+	call debug_dump_al
+	rol rax, 32
+debug_dump_eax:				; RAX is used here instead of EAX to preserve the upper 32-bits
+	rol rax, 40
+	call debug_dump_al
+	rol rax, 8
+	call debug_dump_al
+	rol rax, 16
+debug_dump_ax:
+	rol ax, 8
+	call debug_dump_al
+	rol ax, 8
+debug_dump_al:
+	push rax			; Save RAX
+	push ax				; Save AX for the low nibble
+	shr al, 4			; Shift the high 4 bits into the low 4, high bits cleared
+	or al, '0'			; Add "0"
+	cmp al, '9'+1			; Digit?
+	jl debug_dump_al_h		; Yes, store it
+	add al, 7			; Add offset for character "A"
+debug_dump_al_h:
+	call debug_msg_char
+	pop ax				; Restore AX
+	and al, 0x0F			; Keep only the low 4 bits
+	or al, '0'			; Add "0"
+	cmp al, '9'+1			; Digit?
+	jl debug_dump_al_l		; Yes, store it
+	add al, 7			; Add offset for character "A"
+debug_dump_al_l:
+	call debug_msg_char
+	pop rax				; Restore RAX
+	ret
+; -----------------------------------------------------------------------------
+
+
 EOF:
 	db 0xDE, 0xAD, 0xC0, 0xDE
 

src/sysvar.asm

@@ -6,6 +6,21 @@
 ; =============================================================================
 
 
+; Messages
+msg_pure64:		db 13, 10, 13, 10, '[ Pure64 ]', 0
+msg_ok:			db 'ok', 0
+msg_error:		db 'ERROR', 0
+msg_exception:		db 'EXCEPTION 0x', 0
+msg_pml4:		db 13, 10, 'pml4 ', 0
+msg_boot:		db 13, 10, 'boot ', 0
+msg_bios:		db 'bios', 0
+msg_uefi:		db 'uefi', 0
+msg_acpi:		db 13, 10, 'acpi ', 0
+msg_bsp:		db 13, 10, 'bsp ', 0
+msg_hpet:		db 13, 10, 'hpet ', 0
+msg_smp:		db 13, 10, 'smp ', 0
+msg_kernel:		db 13, 10, 'kernel start', 13, 10, 0
+
 ;CONFIG
 cfg_smpinit:		db 1		; By default SMP is enabled. Set to 0 to disable.