一，powerPC制作文件系统：
1, 准备工作
sudo mkdir /local/tftpboot/comx_p4080/ -p
cd 4080/
sudo cp ./opt/* /opt/ -rf
cp COMX_P4080_SRC_V100R00 ~/ -rf
(然后原来位置的文件夹就没有用了，或者看成剪切过去的)
2，向文件系统中添加文件
cd ~/COMX_P4080_SRC_V100R00/linux/fs/apps/common
mkdir comNet
将所需文件拷贝到该comNet目录下(目录名可更改)
3, 添加自启动方法
sudo gedit ~/COMX_P4080_SRC_V100R00/linux/fs/apps/common/etc/rc.d/rc.local
添加启动文件
2，制作文件系统
cd ~/COMX_P4080_SRC_V100R00/linux/fs/scripts
sudo ./gen_rootfs_ext2.sh
生成的文件系统所在路径：
/local/tftpboot/comx_p4080/
setenv ethaddr 00:01:af:12:23:01;setenv ipaddr 192.168.1.101;setenv netmask 255.255.255.0;setenv gatewayip 192.168.1.1;setenv serverip 192.168.1.209;setenv ethact FM1@DTSEC1;
烧写方法：
run updnorfs
二，测试硬盘读写速度
1,挂载SSD盘
[root@COMX-P4080 root]# ls /dev/nvme*
nvme0n1 nvme0n1p1
[root@COMX-P4080 root]# mkdir /mnt/nvme
[root@COMX-P4080 root]# mount -t ext2 /dev/nvme0n1p1 /mnt/nvme
[root@COMX-P4080 root]# cd /mnt/nvme/
[root@COMX-P4080 nvme]# chmod 777 /bin/dd
[root@COMX-P4080 nvme]# chmod 777 /usr/bin/time
2,测试SSD盘写入速度
[root@COMX-P4080 nvme]# time dd if=/dev/zero of=./test.dbf bs=8k count=128000
128000+0 records in
128000+0 records out
1048576000 bytes (1.0 GB) copied, 2.73546 s, 383 MB/s
real 0m2.747s
user 0m0.056s
sys 0m2.684s
3，测试SSD盘读取速度
[root@COMX-P4080 nvme]# time dd if=./test.dbf of=/dev/null bs=8k
128000+0 records in
128000+0 records out
1048576000 bytes (1.0 GB) copied, 1.04286 s, 1.0 GB/s
real 0m1.044s
user 0m0.032s
sys 0m1.012s
4，硬盘读写程序dd.c源码
#include <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
#include "libbb.h"
enum
{
ifd = STDIN_FILENO,
ofd = STDOUT_FILENO,
};
static const struct suffix_mult dd_suffixes[] =
{
{ "c", 1 },
{ "w", 2 },
{ "b", 512 },
{ "kD", 1000 },
{ "k", 1024 },
{ "K", 1024 }, /* compat with coreutils dd */
{ "MD", 1000000 },
{ "M", 1048576 },
{ "GD", 1000000000 },
{ "G", 1073741824 },
{ }
};
struct globals
{
off_t out_full, out_part, in_full, in_part;
};
#define G (*(struct globals*)&bb_common_bufsiz1)
/* We have to zero it out because of NOEXEC */
#define INIT_G() memset(&G, 0, sizeof(G))
static void dd_output_status(int UNUSED_PARAM cur_signal)
{
/* Deliberately using %u, not %d */
fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
"%"OFF_FMT"u+%"OFF_FMT"u records out\n",
G.in_full, G.in_part,
G.out_full, G.out_part);
}
static ssize_t full_write_or_warn(const void *buf, size_t len,
const char *const filename)
{
ssize_t n = full_write(ofd, buf, len);
if (n < 0)
bb_perror_msg("writing '%s'", filename);
return n;
}
static bool write_and_stats(const void *buf, size_t len, size_t obs,
const char *filename)
{
ssize_t n = full_write_or_warn(buf, len, filename);
if (n < 0)
return 1;
if ((size_t)n == obs)
G.out_full++;
else if (n) /* > 0 */
G.out_part++;
return 0;
}
#if ENABLE_LFS
#define XATOU_SFX xatoull_sfx
#else
#define XATOU_SFX xatoul_sfx
#endif
int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int dd_main(int argc UNUSED_PARAM, char **argv)
{
enum {
/* Must be in the same order as OP_conv_XXX! */
/* (see "flags |= (1 << what)" below) */
FLAG_NOTRUNC = 1 << 0,
FLAG_SYNC = 1 << 1,
FLAG_NOERROR = 1 << 2,
FLAG_FSYNC = 1 << 3,
/* end of conv flags */
FLAG_TWOBUFS = 1 << 4,
FLAG_COUNT = 1 << 5,
};
static const char keywords[] ALIGN1 =
"bs\0""count\0""seek\0""skip\0""if\0""of\0"
#if ENABLE_FEATURE_DD_IBS_OBS
"ibs\0""obs\0""conv\0"
#endif
;
#if ENABLE_FEATURE_DD_IBS_OBS
static const char conv_words[] ALIGN1 =
"notrunc\0""sync\0""noerror\0""fsync\0";
#endif
enum {
OP_bs = 0,
OP_count,
OP_seek,
OP_skip,
OP_if,
OP_of,
#if ENABLE_FEATURE_DD_IBS_OBS
OP_ibs,
OP_obs,
OP_conv,
/* Must be in the same order as FLAG_XXX! */
OP_conv_notrunc = 0,
OP_conv_sync,
OP_conv_noerror,
OP_conv_fsync,
/* Unimplemented conv=XXX: */
//nocreat do not create the output file
//excl fail if the output file already exists
//fdatasync physically write output file data before finishing
//swab swap every pair of input bytes
//lcase change upper case to lower case
//ucase change lower case to upper case
//block pad newline-terminated records with spaces to cbs-size
//unblock replace trailing spaces in cbs-size records with newline
//ascii from EBCDIC to ASCII
//ebcdic from ASCII to EBCDIC
//ibm from ASCII to alternate EBCDIC
#endif
};
int exitcode = EXIT_FAILURE;
size_t ibs = 512, obs = 512;
ssize_t n, w;
char *ibuf, *obuf;
/* And these are all zeroed at once! */
struct {
int flags;
size_t oc;
off_t count;
off_t seek, skip;
const char *infile, *outfile;
} Z;
#define flags (Z.flags )
#define oc (Z.oc )
#define count (Z.count )
#define seek (Z.seek )
#define skip (Z.skip )
#define infile (Z.infile )
#define outfile (Z.outfile)
memset(&Z, 0, sizeof(Z));
INIT_G();
//fflush(NULL); - is this needed because of NOEXEC?
#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
#endif
for (n = 1; argv[n]; n++) {
int what;
char *val;
char *arg = argv[n];
#if ENABLE_DESKTOP
/* "dd --". NB: coreutils 6.9 will complain if they see
* more than one of them. We wouldn't. */
if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
continue;
#endif
val = strchr(arg, '=');
if (val == NULL)
bb_show_usage();
*val = '\0';
what = index_in_strings(keywords, arg);
if (what < 0)
bb_show_usage();
/* *val = '='; - to preserve ps listing? */
val++;
#if ENABLE_FEATURE_DD_IBS_OBS
if (what == OP_ibs) {
/* Must fit into positive ssize_t */
ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
/*continue;*/
}
if (what == OP_obs) {
obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
/*continue;*/
}
if (what == OP_conv) {
while (1) {
/* find ',', replace them with NUL so we can use val for
* index_in_strings() without copying.
* We rely on val being non-null, else strchr would fault.
*/
arg = strchr(val, ',');
if (arg)
*arg = '\0';
what = index_in_strings(conv_words, val);
if (what < 0)
bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
flags |= (1 << what);
if (!arg) /* no ',' left, so this was the last specifier */
break;
/* *arg = ','; - to preserve ps listing? */
val = arg + 1; /* skip this keyword and ',' */
}
continue; /* we trashed 'what', can't fall through */
}
#endif
if (what == OP_bs) {
ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
/*continue;*/
}
/* These can be large: */
if (what == OP_count) {
flags |= FLAG_COUNT;
count = XATOU_SFX(val, dd_suffixes);
/*continue;*/
}
if (what == OP_seek) {
seek = XATOU_SFX(val, dd_suffixes);
/*continue;*/
}
if (what == OP_skip) {
skip = XATOU_SFX(val, dd_suffixes);
/*continue;*/
}
if (what == OP_if) {
infile = val;
/*continue;*/
}
if (what == OP_of) {
outfile = val;
/*continue;*/
}
} /* end of "for (argv[n])" */
//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
ibuf = obuf = xmalloc(ibs);
if (ibs != obs) {
flags |= FLAG_TWOBUFS;
obuf = xmalloc(obs);
}
if (infile != NULL)
xmove_fd(xopen(infile, O_RDONLY), ifd);
else {
infile = bb_msg_standard_input;
}
if (outfile != NULL) {
int oflag = O_WRONLY | O_CREAT;
if (!seek && !(flags & FLAG_NOTRUNC))
oflag |= O_TRUNC;
xmove_fd(xopen(outfile, oflag), ofd);
if (seek && !(flags & FLAG_NOTRUNC)) {
if (ftruncate(ofd, seek * obs) < 0) {
struct stat st;
if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
S_ISDIR(st.st_mode))
goto die_outfile;
}
}
} else {
outfile = bb_msg_standard_output;
}
if (skip) {
if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
while (skip-- > 0) {
n = safe_read(ifd, ibuf, ibs);
if (n < 0)
goto die_infile;
if (n == 0)
break;
}
}
}
if (seek) {
if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
goto die_outfile;
}
while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
memset(ibuf, 0, ibs);
n = safe_read(ifd, ibuf, ibs);
if (n == 0)
break;
if (n < 0) {
if (!(flags & FLAG_NOERROR))
goto die_infile;
n = ibs;
bb_simple_perror_msg(infile);
}
if ((size_t)n == ibs)
G.in_full++;
else {
G.in_part++;
if (flags & FLAG_SYNC) {
memset(ibuf + n, '\0', ibs - n);
n = ibs;
}
}
if (flags & FLAG_TWOBUFS) {
char *tmp = ibuf;
while (n) {
size_t d = obs - oc;
if (d > (size_t)n)
d = n;
memcpy(obuf + oc, tmp, d);
n -= d;
tmp += d;
oc += d;
if (oc == obs) {
if (write_and_stats(obuf, obs, obs, outfile))
goto out_status;
oc = 0;
}
}
} else if (write_and_stats(ibuf, n, obs, outfile))
goto out_status;
if (flags & FLAG_FSYNC) {
if (fsync(ofd) < 0)
goto die_outfile;
}
}
if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
w = full_write_or_warn(obuf, oc, outfile);
if (w < 0) goto out_status;
if (w > 0) G.out_part++;
}
if (close(ifd) < 0) {
die_infile:
bb_simple_perror_msg_and_die(infile);
}
if (close(ofd) < 0) {
die_outfile:
bb_simple_perror_msg_and_die(outfile);
}
exitcode = EXIT_SUCCESS;
out_status:
dd_output_status(0);
return exitcode;
}