understanding memory map in c
$begingroup$
I am working in open source where , I have Zynq-7000 wit ARM processor http://www.ioe.nchu.edu.tw/Pic/CourseItem/4468_20_Zynq_Architecture.pdf
and CMV12000 image sensor (https://ams.com/documents/20143/36005/CMV12000_DS000603_1-00.pdf/f6797bfc-f20b-a0a4-bcea-92e8a02bb112)
I have to memory map this sensors data using mmap in C . I have code but not getting why mmap twice .
static uint32_t cmv_base = 0x60000000;
static uint32_t cmv_size = 0x00400000;
static uint32_t map_base = 0x18000000;
static uint32_t map_size = 0x08000000;
static uint32_t map_addr = 0x00000000;
static char *dev_mem = "/dev/mem";
uint32_t cmv_addr = 0x00000000;
int main ()
{
int fd = open(dev_mem, O_RDWR | O_SYNC);
if (cmv_addr == 0)
cmv_addr = cmv_base;
void *base = mmap((void *)cmv_addr, cmv_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, cmv_base);
cmv_addr = (long unsigned)base;
void *buf = mmap((void *)map_addr, map_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, map_base);
return 0;
}
If this is not the place to ask , From where can I get help ?
please refer any resource .
c memory-optimization
asked 30 mins ago
kanchakancha
1
New contributor
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add a comment |
$begingroup$
I am working in open source where , I have Zynq-7000 wit ARM processor http://www.ioe.nchu.edu.tw/Pic/CourseItem/4468_20_Zynq_Architecture.pdf
and CMV12000 image sensor (https://ams.com/documents/20143/36005/CMV12000_DS000603_1-00.pdf/f6797bfc-f20b-a0a4-bcea-92e8a02bb112)
I have to memory map this sensors data using mmap in C . I have code but not getting why mmap twice .
static uint32_t cmv_base = 0x60000000;
static uint32_t cmv_size = 0x00400000;
static uint32_t map_base = 0x18000000;
static uint32_t map_size = 0x08000000;
static uint32_t map_addr = 0x00000000;
static char *dev_mem = "/dev/mem";
uint32_t cmv_addr = 0x00000000;
int main ()
{
int fd = open(dev_mem, O_RDWR | O_SYNC);
if (cmv_addr == 0)
cmv_addr = cmv_base;
void *base = mmap((void *)cmv_addr, cmv_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, cmv_base);
cmv_addr = (long unsigned)base;
void *buf = mmap((void *)map_addr, map_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, map_base);
return 0;
}
If this is not the place to ask , From where can I get help ?
please refer any resource .
c memory-optimization
asked 30 mins ago
kanchakancha
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
I am working in open source where , I have Zynq-7000 wit ARM processor http://www.ioe.nchu.edu.tw/Pic/CourseItem/4468_20_Zynq_Architecture.pdf
and CMV12000 image sensor (https://ams.com/documents/20143/36005/CMV12000_DS000603_1-00.pdf/f6797bfc-f20b-a0a4-bcea-92e8a02bb112)
I have to memory map this sensors data using mmap in C . I have code but not getting why mmap twice .
static uint32_t cmv_base = 0x60000000;
static uint32_t cmv_size = 0x00400000;
static uint32_t map_base = 0x18000000;
static uint32_t map_size = 0x08000000;
static uint32_t map_addr = 0x00000000;
static char *dev_mem = "/dev/mem";
uint32_t cmv_addr = 0x00000000;
int main ()
{
int fd = open(dev_mem, O_RDWR | O_SYNC);
if (cmv_addr == 0)
cmv_addr = cmv_base;
void *base = mmap((void *)cmv_addr, cmv_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, cmv_base);
cmv_addr = (long unsigned)base;
void *buf = mmap((void *)map_addr, map_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, map_base);
return 0;
}
If this is not the place to ask , From where can I get help ?
please refer any resource .
c memory-optimization
asked 30 mins ago
kanchakancha
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I am working in open source where , I have Zynq-7000 wit ARM processor http://www.ioe.nchu.edu.tw/Pic/CourseItem/4468_20_Zynq_Architecture.pdf
and CMV12000 image sensor (https://ams.com/documents/20143/36005/CMV12000_DS000603_1-00.pdf/f6797bfc-f20b-a0a4-bcea-92e8a02bb112)
I have to memory map this sensors data using mmap in C . I have code but not getting why mmap twice .
static uint32_t cmv_base = 0x60000000;
static uint32_t cmv_size = 0x00400000;
static uint32_t map_base = 0x18000000;
static uint32_t map_size = 0x08000000;
static uint32_t map_addr = 0x00000000;
static char *dev_mem = "/dev/mem";
uint32_t cmv_addr = 0x00000000;
int main ()
{
int fd = open(dev_mem, O_RDWR | O_SYNC);
if (cmv_addr == 0)
cmv_addr = cmv_base;
void *base = mmap((void *)cmv_addr, cmv_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, cmv_base);
cmv_addr = (long unsigned)base;
void *buf = mmap((void *)map_addr, map_size,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, map_base);
return 0;
}
If this is not the place to ask , From where can I get help ?
please refer any resource .
c memory-optimization
c memory-optimization
asked 30 mins ago
kanchakancha
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 30 mins ago
kanchakancha
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 30 mins ago
kanchakancha
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 30 mins ago
kanchakancha
1
asked 30 mins ago
kanchakancha
1
1
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
kancha is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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