/* vi: set sw=4 ts=4: */
/*
 * busybox reimplementation of flashcp
 *
 * (C) 2009 Stefan Seyfried <seife@sphairon.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
//config:config FLASHCP
//config:       bool "flashcp (5.3 kb)"
//config:       default n  # doesn't build on Ubuntu 8.04
//config:       help
//config:       The flashcp binary, inspired by mtd-utils as of git head 5eceb74f7.
//config:       This utility is used to copy images into a MTD device.

//applet:IF_FLASHCP(APPLET(flashcp, BB_DIR_USR_SBIN, BB_SUID_DROP))
/* not NOEXEC: if flash operation stalls, use less memory in "hung" process */

//kbuild:lib-$(CONFIG_FLASHCP) += flashcp.o

//usage:#define flashcp_trivial_usage
//usage:       "[-v] FILE MTD_DEVICE"
//usage:#define flashcp_full_usage "\n\n"
//usage:       "Copy FILE to MTD device\n"
//usage:     "\n        -v      Verbose"

#include "libbb.h"
#include <mtd/mtd-user.h>

/* If 1, simulates "flashing" by writing to existing regular file */
#define MTD_DEBUG 0

#define OPT_v (1 << 0)

#define BUFSIZE (4 * 1024)

static void progress(int mode, uoff_t count, uoff_t total)
{
        uoff_t percent;

        if (!option_mask32) //if (!(option_mask32 & OPT_v))
                return;
        percent = count * 100;
        if (total)
                percent = (unsigned) (percent / total);
        printf("\r%s: %"OFF_FMT"u/%"OFF_FMT"u (%u%%) ",
                (mode < 0) ? "Erasing block" : ((mode == 0) ? "Writing kb" : "Verifying kb"),
                count, total, (unsigned)percent);
        fflush_all();
}

static void progress_newline(void)
{
        if (!option_mask32) //if (!(option_mask32 & OPT_v))
                return;
        bb_putchar('\n');
}

int flashcp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int flashcp_main(int argc UNUSED_PARAM, char **argv)
{
        int fd_f, fd_d; /* input file and mtd device file descriptors */
        int i;
        uoff_t erase_count;
        struct mtd_info_user mtd;
        struct erase_info_user e;
        struct stat statb;
//      const char *filename, *devicename;
        RESERVE_CONFIG_UBUFFER(buf, BUFSIZE);
        RESERVE_CONFIG_UBUFFER(buf2, BUFSIZE);

        /*opts =*/ getopt32(argv, "^" "v" "\0" "=2"/*exactly 2 non-option args: file,dev*/);
        argv += optind;
//      filename = *argv++;
//      devicename = *argv;
#define filename argv[0]
#define devicename argv[1]

        /* open input file and mtd device and do sanity checks */
        fd_f = xopen(filename, O_RDONLY);
        fstat(fd_f, &statb);
        fd_d = xopen(devicename, O_SYNC | O_RDWR);
#if !MTD_DEBUG
        if (ioctl(fd_d, MEMGETINFO, &mtd) < 0) {
                bb_error_msg_and_die("%s is not a MTD flash device", devicename);
        }
        if (statb.st_size > mtd.size) {
                bb_error_msg_and_die("%s bigger than %s", filename, devicename);
        }
#else
        mtd.erasesize = 64 * 1024;
#endif

        /* always erase a complete block */
        erase_count = (uoff_t)(statb.st_size + mtd.erasesize - 1) / mtd.erasesize;
        /* erase 1 block at a time to be able to give verbose output */
        e.length = mtd.erasesize;
#if 0
/* (1) bloat
 * (2) will it work for multi-gigabyte devices?
 * (3) worse wrt error detection granularity
 */
        /* optimization: if not verbose, erase in one go */
        if (!opts) { // if (!(opts & OPT_v))
                e.length = mtd.erasesize * erase_count;
                erase_count = 1;
        }
#endif
        e.start = 0;
        for (i = 1; i <= erase_count; i++) {
                progress(-1, i, erase_count);
#if !MTD_DEBUG
                if (ioctl(fd_d, MEMERASE, &e) < 0) {
                        bb_perror_msg_and_die("erase error at 0x%llx on %s",
                                (long long)e.start, devicename);
                }
#else
                usleep(100*1000);
#endif
                e.start += mtd.erasesize;
        }
        progress_newline();

        /* doing this outer loop gives significantly smaller code
         * than doing two separate loops for writing and verifying */
        for (i = 0; i <= 1; i++) {
                uoff_t done;
                unsigned count;

                xlseek(fd_f, 0, SEEK_SET);
                xlseek(fd_d, 0, SEEK_SET);
                done = 0;
                count = BUFSIZE;
                while (1) {
                        uoff_t rem;

                        progress(i, done / 1024, (uoff_t)statb.st_size / 1024);
                        rem = statb.st_size - done;
                        if (rem == 0)
                                break;
                        if (rem < BUFSIZE)
                                count = rem;
                        xread(fd_f, buf, count);
                        if (i == 0) {
                                int ret;
                                if (count < BUFSIZE)
                                        memset((char*)buf + count, 0, BUFSIZE - count);
                                errno = 0;
                                ret = full_write(fd_d, buf, BUFSIZE);
                                if (ret != BUFSIZE) {
                                        bb_perror_msg_and_die("write error at 0x%"OFF_FMT"x on %s, "
                                                "write returned %d",
                                                done, devicename, ret);
                                }
                        } else { /* i == 1 */
                                xread(fd_d, buf2, count);
                                if (memcmp(buf, buf2, count) != 0) {
                                        bb_error_msg_and_die("verification mismatch at 0x%"OFF_FMT"x", done);
                                }
                        }

                        done += count;
                }

                progress_newline();
        }
        /* we won't come here if there was an error */

        return EXIT_SUCCESS;
}