ASF/AVR32: how to read/write to FLASH

First, open example ASF project on FLASHC read/write. Get code from and paste into your project. Also add *.lds file from example (...asf/avr32/drivers/flashc/flash_example//.lds) into your project. Then add to Linker options next:

--rodata-writable -Wl,--direct-data -T../src/asf/avr32/drivers/flashc/flash_example/at32uc3a3256_evk1104/link_uc3a3256.lds

(first in options line on tab "Miscellaneous" and correct path).
Now build and no any linker errors about regions...

AVR32/ASF: ANSI terminal on UART

It's good known goal - to run terminal (with some kind of shell) of one (or all) of the UARTs. This snippet shows how to process input byte from UART and to emulate ANSI terminal behavior:

/**
 * Handle input byte via USART; process it to emulate edit line behaviour.
 * After processing, sets self->response array to 4 possible responses (until
 * one is NULL). sh_task() will send these responses via UART...
 * Each response can be usual ASCIIZ but also can be ANSI ESC codes, so user
 * terminal should be in ANSI TERM mode. Supported:
 * - BS/DEL - delete prev. char
 * - ^U - delete entire line
 * - ^L - clear screen but keep edited line
 * - TAB - changed to SPACE
 * On error sends BEL ('\7')
 */
void handle_input_byte(sh_t *self, uint8_t ch)
{
    switch (ch) {
        case '\r':
            ch = '\n';
        case '\n':
            self->inpos = 0;
            self->inbuf[0] = 0;
            _SETRESP(self, "\r\n", self->promptbuf, NULL, NULL);
        break;

        /* backspace, del */
        case '\b':
        case '\x7f':
            if (self->inpos > 0) {
                self->inpos--;
                self->inbuf[self->inpos] = 0;
                _SETRESP(self, "\b \b", NULL, NULL, NULL);
            } else {
                _SETRESP(self, "\a", NULL, NULL, NULL);
            }
        break;

        /* ^U - del line */
        case 'u' & 0x1f:
            self->inpos = 0;
            self->inbuf[self->inpos] = 0;
            _SETRESP(self, "\x1B[2K\r", self->promptbuf, NULL, NULL);
        break;

        /* ^L - clear screen */
        case 'l' & 0x1f:
            _SETRESP(self, "\x1B[2J\x1B[H", self->promptbuf, self->inbuf, NULL);
        break;

        /* all other chars */
        case '\t':
            ch = ' ';
        default:
            if ((ch >= (uint8_t)' ' && ch <= (uint8_t)'\x7e')
                            || ch >= (uint8_t)'\xa0') {
                // printable
                if (self->inpos < sizeofarray(self->inbuf) - 1) {
                    // in bounds (-2 is for ch, -1 is for '\0')
                    self->inbuf[self->inpos++] = ch;
                    self->inbuf[self->inpos] = 0;
                    _SETRESP(self, self->inbuf + (self->inpos-1), NULL, NULL, NULL);
                } else {
                    _SETRESP(self, "\a", NULL, NULL, NULL);
                }
            } else {
                // non-printable
                _SETRESP(self, "\a", NULL, NULL, NULL);
            }
        break;
    }
}

Nothing special: no support of editing in the middle of the line, only at the end, clearing of line, screen, deleting last char. It generates ANSI ESC sequencies. self is the pointer to special struct with inbuf char buffer and inpos - current position of added bytes, so entered line will be in the inbuf. _SETRESP() is the macros - it sets 4 char pointers to be sent in sh_task() function (sends all 4 or until one of them is NULL) - it's looks similar like yielding of responces in WSGI Python Web application, but limited with 0 to 4 parts only :)
sh_task() is call in main loop and sends these responces, handle_input_byte() is called in UART ISR routine to save input and prepare responces. Using of struct, wrapped all needed resources helps us to avoid global and single shell only, so we can have several shells on several UARTs.
sizeofarray() is trivial macros, returns array items number. Short example how it looks:

ANSI terminal on AVR chip from bapcyk on Vimeo.