- Android dosbox serial port how to#
- Android dosbox serial port serial#
- Android dosbox serial port android#
The line status register (LSR) is at 03FD (PORT + 5). The line control register (LCR) is at 03FB (PORT + 3). It's even true for programming in general.
Android dosbox serial port serial#
I checked USB to serial functionality in DOSBOX it is working perfectly url removed, login to view i was unable to MAP the Serialport to dosbox.
Android dosbox serial port android#
I am working on android x86 emulator with virtuabox in PC environment. Īccuracy will be key in programming this hardware. I was able to do configuration of Serial port in url removed, login to view but it was not working in android devices. (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled) If serial is not faulty set it in normal operation mode Check if serial is faulty (i.e: not same byte as sent) Outb(PORT + 0, 0xAE) // Test serial chip (send byte 0xAE and check if serial returns same byte) Outb(PORT + 4, 0x1E) // Set in loopback mode, test the serial chip Outb(PORT + 4, 0x0B) // IRQs enabled, RTS/DSR set Outb(PORT + 2, 0xC7) // Enable FIFO, clear them, with 14-byte threshold Outb(PORT + 3, 0x03) // 8 bits, no parity, one stop bit Outb(PORT + 0, 0x03) // Set divisor to 3 (lo byte) 38400 baud Outb(PORT + 3, 0x80) // Enable DLAB (set baud rate divisor) Outb(PORT + 1, 0x00) // Disable all interrupts The C code given for reference: define PORT 0x3f8 // COM1
This time NASM will expand your outb macro into these 3 instructions: mov dx, PORT + 1 Same as `mov dx, 0x03F9` And the outb(PORT + 1, 0x00) instruction becomes outb PORT + 1, 0x00 in assembly. It has define PORT 0x3f8 which in assembly becomes PORT equ 0x03F8. However those brackets have nothing to do with the same brackets used in the assembly programming language. In your defense, the wiki article does use square brackets when it says that you should send data to e.g. Given the outb macro definition, NASM will expand your outb, 0x00 macro invokation into: mov dx, īecause of the square brackets, the first instruction will load DX from memory, and sadly that does not contain the intended port address (0x03F9)! What you get is 0x0003, composed from the high byte of the word stored at com1 and the next byte in memory that happens to be 0 because of the times zero-padding.
Android dosbox serial port how to#
I have some debugging primitives and everything, seems to go smoothly until the line outb, 0x03 afterwards, if I read the line control register I get an error but I am not to sure how to interpret it (it seems to be an error related to stop bits, error 3) Outb, 0x1e set in loopback mode, test the serial chip Outb, 0xc7 enable fifo, clear them, with 14-byte threshold Outb, 0x03 8 bits, no parity, one stop bit Outb, 0x03 Set divisor to 3 (lo byte) 38440 baud Outb, 0x80 enable DLAB (set baud rate divisor) Org 0x7c00 set the origin at the start of the bootloader address space My current code looks like this, and should be a direct translation of their C code. (I am pretty new to asm and to bios related stuff so my code may be very wrong or may be there is a need to initialize other things before I can initialize the serial port)
I want to use the serial port COM1 without using the BIOS interrupt 14h, and for this purpose I am following the tutorial at osdev but I have some problems during the initialization.
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