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author | Josh Blum <josh@joshknows.com> | 2010-12-22 19:19:14 -0800 |
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committer | Josh Blum <josh@joshknows.com> | 2010-12-22 19:19:14 -0800 |
commit | 22ed61f97815856bf74cec25ae6bca88bfbe5f44 (patch) | |
tree | 7d87d49b46f9507ff10486097e6d79e4bee4cb81 /firmware/zpu/lib/gdbstub2.c | |
parent | 71fc99d006f2347a356c5339905593f64ff902ec (diff) | |
download | uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.tar.gz uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.tar.bz2 uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.zip |
zpu: renamed the directory for the usrp2 fw to zpu to reflect the cpu type
Diffstat (limited to 'firmware/zpu/lib/gdbstub2.c')
-rw-r--r-- | firmware/zpu/lib/gdbstub2.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/firmware/zpu/lib/gdbstub2.c b/firmware/zpu/lib/gdbstub2.c new file mode 100644 index 000000000..4c63dfce2 --- /dev/null +++ b/firmware/zpu/lib/gdbstub2.c @@ -0,0 +1,506 @@ +/* -*- c++ -*- */ +/* + * Copyright 2009 Ettus Research LLC + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* + * Implement a eensy weensy part of the GDB Remote Serial Protocol + * + * See Appendix D of the GDB manual + * + * m<addr>,<length> -- read <length> bytes of memory starting at <addr> + * Reply: + * XX... XX... is memory contents in hex + * ENN ENN NN is a hex error number + * + * M<addr>,<length>:XX... -- write memory, data in hex + * Reply: + * OK for success + * ENN for an error. NN is a hex error number + * + * X<addr>,<length>:XX... -- write memory, data in binary + * Reply: + * OK for success + * ENN for an error. NN is a hex error number + * + * c<addr> -- continue. <addr> is the address to resume (goto). + * Reply: <none> + * + * \x80 New Format... + */ + +#include "gdbstub2.h" +#include "loader_parser.h" +#include "hal_uart.h" +#include <stdbool.h> +#include <stddef.h> + +#define MAX_PACKET 1024 + +/* + * Get raw character from serial port, no echo. + */ +static inline int +gdb_getc(void) +{ + return hal_uart_getc(); +} + +/* + * Put character to serial port. Raw output. + */ +static inline void +gdb_putc(int ch) +{ + hal_uart_putc(ch); +} + +// ------------------------------------------------------------------------ + +#define GDB_ESCAPE 0x7d + +static unsigned char hex_table[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' +}; + +static int +put_hex8_checksum(int ch, int checksum) +{ + unsigned char t = hex_table[(ch >> 4) & 0xf]; + checksum += t; + gdb_putc(t); + + t = hex_table[ch & 0xf]; + checksum += t; + gdb_putc(t); + return checksum; +} + +static void +put_hex8(int ch) +{ + put_hex8_checksum(ch, 0); +} + +static bool +hex4_to_bin(int ch, int *value) +{ + if ('0' <= ch && ch <= '9'){ + *value = ch - '0'; + return true; + } + if ('a' <= ch && ch <= 'f'){ + *value = ch - 'a' + 10; + return true; + } + if ('A' <= ch && ch <= 'F'){ + *value = ch - 'A' + 10; + return true; + } + *value = 0; + return false; +} + +static bool +hex8_to_bin(const unsigned char *s, int *value) +{ + int v0, v1; + if (hex4_to_bin(s[0], &v0) && hex4_to_bin(s[1], &v1)){ + *value = (v0 << 4) | v1; + return true; + } + return false; +} + +static bool +hex_to_bin_array(unsigned char *binary_data, const unsigned char *hex_data, size_t nbytes) +{ + for (size_t i = 0; i < nbytes; i++){ + int t; + if (!hex8_to_bin(&hex_data[2*i], &t)) + return false; + binary_data[i] = t; + } + return true; +} + +static bool +needs_escaping(int ch) +{ + return ch == '$' || ch == '#' || ch == GDB_ESCAPE; +} + +/* + * \brief Wait for a packet. + * \param[out] pkt_buf gets the received packet payload. + * \param[in] max_size is the maximum number of bytes to write into \p pkt_buf. + * \param[out] actual_size is the number of bytes written to \p pkt_buf. + * + * \returns true iff the payload fits and the checksum is OK. + * + * Packets have this format: + * + * $<packet-data>#<checksum> + * + * Where <packet-data> is anything and <checksum> is a two byte hex + * checksum. In <packet-data> '$', '#' and 0x7d are escaped with 0x7d. + * The checksum is computed as the modulo 256 sum of all characters + * btween the leading '$' and the trailing '#' (an 8-bit unsigned + * checksum). + */ +static bool +get_packet(unsigned char *pkt_buf, size_t max_size, size_t *actual_size) +{ + typedef enum states { + LOOKING_FOR_DOLLAR, + LOOKING_FOR_HASH, + CSUM1, + CSUM2, + } state_t; + + *actual_size = 0; + unsigned char csum[2] = {0, 0}; + state_t state = LOOKING_FOR_DOLLAR; + size_t pi = 0; + + while (1){ + int ch = gdb_getc(); + + switch (state){ + case LOOKING_FOR_DOLLAR: + if (ch == '$'){ + pi = 0; + state = LOOKING_FOR_HASH; + } + else if (ch == '#'){ // most likely missed the $ + return false; + } + break; + + case LOOKING_FOR_HASH: + if (ch == '$'){ + return false; + } + else if (ch == '#'){ + state = CSUM1; + } + else { + if (pi >= max_size) // payload too big + return false; + + if (ch == GDB_ESCAPE) + ch = gdb_getc(); + + pkt_buf[pi++] = ch; + } + break; + + case CSUM1: + csum[0] = ch; + state = CSUM2; + break; + + case CSUM2: + csum[1] = ch; + *actual_size = pi; + + // accept .. as a correct checksum + if (csum[0] == '.' && csum[1] == '.') + return true; + + int expected_checksum; + if (!hex8_to_bin(csum, &expected_checksum)) + return false; + + int checksum = 0; + for (size_t i = 0; i < pi; i++) + checksum += pkt_buf[i]; + + checksum &= 0xff; + return checksum == expected_checksum; + } + } +} + +static void +put_packet_trailer(int checksum) +{ + gdb_putc('#'); + put_hex8(checksum & 0xff); + gdb_putc('\r'); + gdb_putc('\n'); +} + +static void +put_packet(const unsigned char *pkt_buf, size_t size) +{ + gdb_putc('$'); + + int checksum = 0; + for (size_t i = 0; i < size; i++){ + int ch = pkt_buf[i]; + if (needs_escaping(ch)) + gdb_putc(GDB_ESCAPE); + gdb_putc(ch); + checksum += ch; + } + put_packet_trailer(checksum); +} + +/*! + * Read a hex number + * + * \param[inout] bufptr - pointer to pointer to buffer (updated on return) + * \param[in] end - one past end of valid data in buf + * \param[out] value - the parsed value + * + * \returns true iff a valid hex number was read from bufptr + */ +static bool +parse_number(const unsigned char **bufptr, const unsigned char *end, unsigned int *value) +{ + const unsigned char *buf = *bufptr; + unsigned int v = 0; + bool valid = false; + int nibble; + + while (buf < end && hex4_to_bin(*buf, &nibble)){ + valid = true; + v = (v << 4) | nibble; + buf++; + } + + *value = v; + *bufptr = buf; + return valid; +} + +static bool +parse_char(const unsigned char **bufptr, const unsigned char *end, unsigned char *ch) +{ + const unsigned char *buf = *bufptr; + if (buf < end){ + *ch = *buf++; + *bufptr = buf; + return true; + } + return false; +} + +static bool +expect_char(const unsigned char **bufptr, const unsigned char *end, unsigned char expected) +{ + unsigned char ch; + return parse_char(bufptr, end, &ch) && ch == expected; +} + +static bool +expect_end(const unsigned char **bufptr, const unsigned char *end) +{ + return *bufptr == end; +} + +static bool +parse_addr_length(const unsigned char **bufptr, const unsigned char *end, + unsigned int *addr, unsigned int *length) +{ + return (parse_number(bufptr, end, addr) + && expect_char(bufptr, end, ',') + && parse_number(bufptr, end, length)); +} + +static void +put_error(int error) +{ + unsigned char buf[3]; + buf[0] = 'E'; + buf[1] = hex_table[(error >> 4) & 0xf]; + buf[2] = hex_table[error & 0xf]; + + put_packet(buf, sizeof(buf)); +} + +static void +put_ok(void) +{ + const unsigned char buf[2] = "OK"; + put_packet(buf, sizeof(buf)); +} + +/* + * Read memory and send the reply. + * We do it on the fly so that our packet size is effectively unlimited + */ +static void +read_memory(unsigned int addr, unsigned int nbytes) +{ + int checksum = 0; + gdb_putc('$'); + + if ((addr & 0x3) == 0 && (nbytes & 0x3) == 0){ // word aligned + union { + unsigned int i; + unsigned char c[4]; + } u; + + unsigned int *p = (unsigned int *) addr; + unsigned int length = nbytes / 4; + + for (unsigned int i = 0; i < length; i++){ + u.i = p[i]; // do a word read + checksum = put_hex8_checksum(u.c[0], checksum); + checksum = put_hex8_checksum(u.c[1], checksum); + checksum = put_hex8_checksum(u.c[2], checksum); + checksum = put_hex8_checksum(u.c[3], checksum); + } + } + else { // byte aligned + unsigned char *p = (unsigned char *) addr; + for (unsigned int i = 0; i < nbytes; i++) + checksum = put_hex8_checksum(p[i], checksum); + } + + put_packet_trailer(checksum); +} + +static unsigned int +get_unaligned_int(const unsigned char *p) +{ + // we're bigendian + return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | (p[3]); +} + +static bool +write_memory(unsigned int addr, size_t nbytes, + const unsigned char *data) +{ + if ((addr & 0x3) == 0 && (nbytes & 0x3) == 0){ // word-aligned dst + unsigned int *dst = (unsigned int *) addr; + size_t length = nbytes / 4; + for (size_t i = 0; i < length; i++){ + unsigned int t = get_unaligned_int(&data[4*i]); + dst[i] = t; // word writes + } + } + else { // non-word-aligned dst + unsigned char *dst = (unsigned char *) addr; + for (size_t i = 0; i < nbytes; i++){ + dst[i] = data[i]; + } + } + return true; +} + +void +gdbstub2_main_loop(void) +{ + unsigned char inpkt[MAX_PACKET + 24]; + unsigned char binary_data[MAX_PACKET/2] __attribute__((aligned (4))); + + hal_uart_set_mode(UART_MODE_RAW); //tell UART HAL not to map \n to \r\n + + while (1){ + size_t inpkt_len; + bool ok = get_packet(inpkt, sizeof(inpkt), &inpkt_len); + if (!ok){ + gdb_putc('-'); + continue; + } + gdb_putc('+'); + + const unsigned char *buf = inpkt; + const unsigned char *end = inpkt + inpkt_len; + unsigned char ch; + + if (!parse_char(&buf, end, &ch)){ // empty packet + put_packet(0, 0); + continue; + } + + unsigned int addr; + unsigned int length; + + switch(ch){ + case 'm': // m<addr>,<length> -- read <length> bytes starting at <addr> + if (!(parse_addr_length(&buf, end, &addr, &length) && expect_end(&buf, end))){ + put_error(1); + } + else { + read_memory(addr, length); + } + break; + + case 'M': // M<addr>,<length>:XX... -- write <length> bytes starting at <addr> + // XX... is the data in hex + if (!(parse_addr_length(&buf, end, &addr, &length) + && expect_char(&buf, end, ':') + && (end - buf) == 2 * length)){ + put_error(1); + } + else { + if (!hex_to_bin_array(binary_data, buf, length)) + put_error(2); + else if (!write_memory(addr, length, binary_data)) + put_error(3); + else + put_ok(); + } + break; + + case 'X': // X<addr>,<length>:XX... -- write <length> bytes starting at <addr> + // XX... is the data in binary + if (!(parse_addr_length(&buf, end, &addr, &length) + && expect_char(&buf, end, ':') + && (end - buf) == length)){ + put_error(1); + } + else { + if (!write_memory(addr, length, buf)) + put_error(3); + else + put_ok(); + } + break; + + case 'c': // c<addr> -- continue. <addr> is the address to resume (goto). + if (!(parse_number(&buf, end, &addr) + && expect_end(&buf, end))){ + put_error(1); + } + else { + typedef void (*fptr_t)(void); + (*(fptr_t) addr)(); // most likely no return + } + break; +/* + case 0x80: + { + unsigned char *output = binary_data; // reuse + size_t sizeof_output = sizeof(binary_data); + size_t actual_olen; + loader_parser(buf, end-buf, + output, sizeof_output, &actual_olen); + put_packet(output, actual_olen); + } + break; +*/ + default: // unknown packet type + put_packet(0, 0); + break; + } + } +} |