emailler/client/examples/httpd.asm

451 lines
9.3 KiB
NASM

;NB65 API example in DASM format (http://www.atari2600.org/DASM/)
processor 6502
include "../inc/nb65_constants.i"
;useful macros
mac ldax
lda [{1}]
ldx [{1}]+1
endm
mac ldaxi
lda #<[{1}]
ldx #>[{1}]
endm
mac stax
sta [{1}]
stx [{1}]+1
endm
mac cout
lda [{1}]
jsr print_a
endm
mac print_cr
cout #13
jsr print_a
endm
mac nb65call
ldy [{1}]
jsr NB65_DISPATCH_VECTOR
endm
mac print
ldaxi [{1}]
ldy #NB65_PRINT_ASCIIZ
jsr NB65_DISPATCH_VECTOR
endm
protocol_http equ $00
protocol_gopher equ $01
;some routines & zero page variables
print_a equ $ffd2
temp_ptr equ $FB ; scratch space in page zero
;start of code
;NO BASIC stub! needs to be direct booted via TFTP
org $1000
jsr init_tod
ldaxi #NB65_CART_SIGNATURE ;where signature should be in cartridge (if cart is banked in)
jsr look_for_signature
bcc found_nb65_signature
ldaxi #NB65_RAM_STUB_SIGNATURE ;where signature should be in a RAM stub
jsr look_for_signature
bcs nb65_signature_not_found
jsr NB65_RAM_STUB_ACTIVATE ;we need to turn on NB65 cartridge
jmp found_nb65_signature
nb65_signature_not_found
ldaxi #nb65_api_not_found_message
jsr print_ax
rts
found_nb65_signature
lda NB65_API_VERSION
cmp #02
bpl .version_ok
print incorrect_version
jmp reset_after_keypress
.version_ok
print #initializing
nb65call #NB65_INITIALIZE
bcc .init_ok
print_cr
print #failed
print_cr
jsr print_errorcode
jmp reset_after_keypress
.init_ok
;if we got here, we have found the NB65 API and initialised the IP stack
;print out the current configuration
nb65call #NB65_PRINT_IP_CONFIG
listen_on_port_80
ldaxi #scratch_buffer
stax tcp_buffer_ptr
print #waiting
ldaxi #80 ;port number
stax nb65_param_buffer+NB65_TCP_PORT
stx nb65_param_buffer+NB65_TCP_REMOTE_IP
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+1
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+2
stx nb65_param_buffer+NB65_TCP_REMOTE_IP+3
ldaxi #http_callback
stax nb65_param_buffer+NB65_TCP_CALLBACK
ldaxi #nb65_param_buffer
nb65call #NB65_TCP_CONNECT ;wait for inbound connect
bcc .connected_ok
print #error_while_waiting
jsr print_errorcode
jmp reset_after_keypress
.connected_ok
print #ok
lda #0
sta connection_closed
sta found_eol
clc
lda $dc09 ;time of day clock: seconds (in BCD)
sed
adc #$30
cmp #$60
bcc .timeout_set
sec
sbc #$60
.timeout_set:
cld
sta connection_timeout_seconds
.main_polling_loop
jsr NB65_PERIODIC_PROCESSING_VECTOR
lda found_eol
bne .got_eol
lda $dc09 ;time of day clock: seconds
cmp connection_timeout_seconds
beq .connection_timed_out
; nb65call #NB65_PRINT_HEX
lda connection_closed
beq .main_polling_loop
jmp listen_on_port_80
.connection_timed_out:
print #timeout
jmp listen_on_port_80
.got_eol:
;if we have a CR, we have got enough of a request to know if it's a HTTP or gopher request
lda #"G"
cmp scratch_buffer
bne .gopher
lda #"E"
cmp scratch_buffer+1
bne .gopher
lda #"T"
cmp scratch_buffer+2
bne .gopher
lda #" "
cmp scratch_buffer+3
bne .gopher
lda #protocol_http
sta protocol
print #http
ldx #4
jmp .copy_selector
.gopher
jsr print_a
lda #protocol_gopher
sta protocol
print #gopher
ldx #0
.copy_selector:
lda scratch_buffer,x
cmp #"/"
bne .copy_one_char
inx
.copy_one_char
lda scratch_buffer,x
cmp #$20
bcc .last_char_in_selector
sta selector,y
inx
iny
bne .copy_one_char
.last_char_in_selector
lda #0
sta selector,y
print #selector
;ldaxi #html_length
ldaxi #index_html_buffer_length
stax nb65_param_buffer+NB65_TCP_PAYLOAD_LENGTH
; ldaxi #html
ldaxi #index_html_buffer
stax nb65_param_buffer+NB65_TCP_PAYLOAD_POINTER
ldaxi #nb65_param_buffer
nb65call #NB65_SEND_TCP_PACKET
nb65call #NB65_TCP_CLOSE_CONNECTION
.start_new_connection
jmp listen_on_port_80
;look for NB65 signature at location pointed at by AX
look_for_signature subroutine
stax temp_ptr
ldy #3
.check_one_byte
lda (temp_ptr),y
cmp nb65_signature,y
bne .bad_match
dey
bpl .check_one_byte
clc
rts
.bad_match
sec
rts
print_ax subroutine
stax temp_ptr
ldy #0
.next_char
lda (temp_ptr),y
beq .done
jsr print_a
iny
jmp .next_char
.done
rts
get_key
jsr $ffe4
cmp #0
beq get_key
rts
reset_after_keypress
print #press_a_key_to_continue
jsr get_key
jmp $fce2 ;do a cold start
;init the Time-Of-Day clock - cribbed from http://codebase64.org/doku.php?id=base:initialize_tod_clock_on_all_platforms
init_tod:
sei
lda #0
sta $d011 ;Turn off display to disable badlines
sta $dc0e ;Set TOD Clock Frequency to 60Hz
sta $dc0f ;Enable Set-TOD-Clock
sta $dc0b ;Set TOD-Clock to 0 (hours)
sta $dc0a ;- (minutes)
sta $dc09 ;- (seconds)
sta $dc08 ;- (deciseconds)
lda $dc08 ;
.wait_raster
cmp $dc08 ;Sync raster to TOD Clock Frequency
beq .wait_raster
ldx #0 ;Prep X and Y for 16 bit
ldy #0 ; counter operation
lda $dc08 ;Read deciseconds
.loop1
inx ;2 -+
bne .loop2 ;2/3 | Do 16 bit count up on
iny ;2 | X(lo) and Y(hi) regs in a
jmp .loop3 ;3 | fixed cycle manner
.loop2
nop ;2 |
nop ;2 -+
.loop3
cmp $dc08 ;4 - Did 1 decisecond pass?
beq .loop1 ;3 - If not, loop-di-doop
;Each loop = 16 cycles
;If less than 118230 cycles passed, TOD is
;clocked at 60Hz. If 118230 or more cycles
;passed, TOD is clocked at 50Hz.
;It might be a good idea to account for a bit
;of slack and since every loop is 16 cycles,
;28*256 loops = 114688 cycles, which seems to be
;acceptable. That means we need to check for
;a Y value of 28.
cpy #28 ;Did 114688 cycles or less go by?
bcc .hertz_correct ;- Then we already have correct 60Hz $dc0e value
lda #$80 ;Otherwise, we need to set it to 50Hz
sta $dc0e
.hertz_correct
lda #$1b ;Enable the display again
sta $d011
cli
rts
print_errorcode
print #error_code
nb65call #NB65_GET_LAST_ERROR
nb65call #NB65_PRINT_HEX
print_cr
rts
;http callback - will be executed whenever data arrives on the TCP connection
http_callback
ldaxi #nb65_param_buffer
nb65call #NB65_GET_INPUT_PACKET_INFO
lda nb65_param_buffer+NB65_PAYLOAD_LENGTH+1
cmp #$ff
bne .not_eof
lda #1
sta connection_closed
rts
.not_eof
lda #"*"
jsr print_a
ldax nb65_param_buffer+NB65_PAYLOAD_POINTER
stax tcp_inbound_data_ptr
ldax nb65_param_buffer+NB65_PAYLOAD_LENGTH
stax tcp_inbound_data_length
;copy this chunk to our input buffer
ldax tcp_buffer_ptr
stax nb65_param_buffer+NB65_BLOCK_DEST
ldax tcp_inbound_data_ptr
stax nb65_param_buffer+NB65_BLOCK_SRC
ldax tcp_inbound_data_length
stax nb65_param_buffer+NB65_BLOCK_SIZE
ldaxi #nb65_param_buffer
nb65call #NB65_BLOCK_COPY
;increment the pointer into the input buffer
clc
lda tcp_buffer_ptr
adc tcp_inbound_data_length
sta tcp_buffer_ptr
sta temp_ptr
lda tcp_buffer_ptr+1
adc tcp_inbound_data_length+1
sta tcp_buffer_ptr+1
sta temp_ptr
;put a null byte at the end (assumes we have set temp_ptr already)
lda #0
tay
sta (temp_ptr),y
;look for CR or LF in input
sta found_eol
ldaxi #scratch_buffer
stax get_next_byte+1
.look_for_eol
jsr get_next_byte
cmp #$0a
beq .found_eol
cmp #$0d
bne .not_eol
.found_eol
inc found_eol
rts
.not_eol
cmp #0
bne .look_for_eol
rts
;constants
nb65_api_not_found_message dc.b "ERROR - NB65 API NOT FOUND.",13,0
incorrect_version dc.b "ERROR - NB65 API MUST BE AT LEAST VERSION 2.",13,0
nb65_signature dc.b $4E,$42,$36,$35 ; "NB65" - API signature
initializing dc.b "INITIALIZING ",13,0
error_code dc.b "ERROR CODE: $",0
error_while_waiting dc.b "ERROR WHILE "
waiting dc.b "WAITING FOR CLIENT CONNECTION",13,0
press_a_key_to_continue dc.b "PRESS ANY KEY TO CONTINUE",0
mode dc.b " MODE",13,0
disconnected dc.b 13,"CONNECTION CLOSED",13,0
failed dc.b "FAILED ", 0
ok dc.b "OK ", 0
timeout dc.b 13,"CONNECTION TIMEOUT ",13, 0
transmission_error dc.b "ERROR WHILE SENDING ",0
http: dc.b "HTTP: ",0
gopher: dc.b "GOPHER: ",0
;self modifying code
get_next_byte
lda $ffff
inc get_next_byte+1
bne .skip
inc get_next_byte+2
.skip
rts
reset_output_buffer
sta emit_a+1
stx emit_a+2
lda #0
sta output_buffer_length
sta output_buffer_length+1
rts
emit_a
sta $ffff
inc emit_a+1
bne .1
inc emit_a+2
.1
inc output_buffer_length
bne .2
inc output_buffer_length+1
.2
rts
;variables
protocol ds.b 1
connection_closed ds.b 1
connection_timeout_seconds ds.b 1
found_eol ds.b 1
nb65_param_buffer DS.B $20
tcp_buffer_ptr ds.b 2
scan_ptr ds.b 2
tcp_inbound_data_ptr ds.b 2
tcp_inbound_data_length ds.b 2
output_buffer_length: ds.b 2
selector: ds.b $100
scratch_buffer: ds.b $1000
index_html_buffer: ds.b $1000
index_html_buffer_length: ds.b 2
gopher_map_buffer: ds.b $1000