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util/cbmem: add option to read CBMEM from file instead of RAM
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Signed-off-by: Krystian Hebel <[email protected]>
Change-Id: I273e1eed320b3d99a57ae5b361b79238f40cf825
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@krystian-hebel
krystian-hebel committed Mar 28, 2023
1 parent a75b177 commit b1bb190
Showing 1 changed file with 99 additions and 42 deletions.
141 changes: 99 additions & 42 deletions util/cbmem/cbmem.c
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Original file line number Diff line number Diff line change
Expand Up @@ -58,12 +58,20 @@ static int verbose = 0;
#define debug(x...) if(verbose) printf(x)

/* File handle used to access /dev/mem */
static int mem_fd;
static int mem_fd = -1;
static struct mapping lbtable_mapping;

/* File handle used to parse CBMEM from file instead of RAM */
static int file_fd = -1;

/* TSC frequency from the LB_TAG_TSC_INFO record. 0 if not present. */
static uint32_t tsc_freq_khz = 0;

static struct lb_cbmem_ref timestamps;
static struct lb_cbmem_ref console;
static struct lb_cbmem_ref tcpa_log;
static struct lb_memory_range cbmem;

static void die(const char *msg)
{
if (msg)
Expand Down Expand Up @@ -101,40 +109,74 @@ static void *mapping_virt(const struct mapping *mapping)
static void *map_memory_with_prot(struct mapping *mapping,
unsigned long long phys, size_t sz, int prot)
{
void *v;
unsigned long long page_size;
if (file_fd < 0) {
void *v;
unsigned long long page_size;

page_size = system_page_size();
page_size = system_page_size();

mapping->virt = NULL;
mapping->offset = phys % page_size;
mapping->virt_size = sz + mapping->offset;
mapping->size = sz;
mapping->phys = phys;

if (size_to_mib(mapping->virt_size) == 0) {
debug("Mapping %zuB of physical memory at 0x%llx (requested 0x%llx).\n",
mapping->virt_size, phys - mapping->offset, phys);
} else {
debug("Mapping %zuMB of physical memory at 0x%llx (requested 0x%llx).\n",
size_to_mib(mapping->virt_size), phys - mapping->offset,
phys);
}
mapping->virt = NULL;
mapping->offset = phys % page_size;
mapping->virt_size = sz + mapping->offset;
mapping->size = sz;
mapping->phys = phys;

v = mmap(NULL, mapping->virt_size, prot, MAP_SHARED, mem_fd,
phys - mapping->offset);
if (size_to_mib(mapping->virt_size) == 0) {
debug("Mapping %zuB of physical memory at 0x%llx (requested 0x%llx).\n",
mapping->virt_size, phys - mapping->offset, phys);
} else {
debug("Mapping %zuMB of physical memory at 0x%llx (requested 0x%llx).\n",
size_to_mib(mapping->virt_size), phys - mapping->offset,
phys);
}

if (v == MAP_FAILED) {
debug("Mapping failed %zuB of physical memory at 0x%llx.\n",
mapping->virt_size, phys - mapping->offset);
return NULL;
}
v = mmap(NULL, mapping->virt_size, prot, MAP_SHARED, mem_fd,
phys - mapping->offset);

if (v == MAP_FAILED) {
debug("Mapping failed %zuB of physical memory at 0x%llx.\n",
mapping->virt_size, phys - mapping->offset);
return NULL;
}

mapping->virt = v;

if (mapping->offset != 0)
debug(" ... padding virtual address with 0x%zx bytes.\n",
mapping->offset);
} else {
ssize_t ret;
mapping->virt = malloc(sz);
mapping->offset = 0;
mapping->virt_size = sz;
mapping->size = sz;
mapping->phys = phys;

debug("map_memory phys = %llx, size = %zuB, cbmem.start = %lx\n", phys, sz, cbmem.start);

if (mapping->virt == NULL) {
debug("Couldn't allocate %zuB of memory.\n", sz);
return NULL;
}

mapping->virt = v;
if (lseek(file_fd, mapping->phys - cbmem.start, SEEK_SET) < 0) {
debug("Couldn't read file from offset %llx.\n",
mapping->phys - cbmem.start);
free(mapping->virt);
return NULL;
}

if (mapping->offset != 0)
debug(" ... padding virtual address with 0x%zx bytes.\n",
mapping->offset);
ret = read(file_fd, mapping->virt, sz);
if (ret < 0) {
debug("Error reading file: %s\n", strerror(errno));
free(mapping->virt);
return NULL;
}
if ((size_t)ret != sz) {
debug("Truncated read from offset %llx, requested %zuB, got %zuB.\n",
mapping->phys - cbmem.start, sz, ret);
}
}

return mapping_virt(mapping);
}
Expand All @@ -153,7 +195,11 @@ static int unmap_memory(struct mapping *mapping)
if (mapping->virt == NULL)
return -1;

munmap(mapping->virt, mapping->virt_size);
if (file_fd < 0)
munmap(mapping->virt, mapping->virt_size);
else
free(mapping->virt);

mapping->virt = NULL;
mapping->offset = 0;
mapping->virt_size = 0;
Expand Down Expand Up @@ -265,11 +311,6 @@ static int find_cbmem_entry(uint32_t id, uint64_t *addr, size_t *size)
* none found.
*/

static struct lb_cbmem_ref timestamps;
static struct lb_cbmem_ref console;
static struct lb_cbmem_ref tcpa_log;
static struct lb_memory_range cbmem;

/* This is a work-around for a nasty problem introduced by initially having
* pointer sized entries in the lb_cbmem_ref structures. This caused problems
* on 64bit x86 systems because coreboot is 32bit on those systems.
Expand Down Expand Up @@ -1340,6 +1381,7 @@ static void print_usage(const char *name, int exit_code)
" -S | --stacked-timestamps: print stacked timestamps (e.g. for flame graph tools)\n"
" -a | --add-timestamp ID: append timestamp with ID\n"
" -L | --tcpa-log print TCPA log\n"
" -f | --file FILE: read CBMEM from FILE instead of memory\n"
" -V | --verbose: verbose (debugging) output\n"
" -v | --version: print the version\n"
" -h | --help: print this help\n"
Expand Down Expand Up @@ -1493,12 +1535,13 @@ int main(int argc, char** argv)
{"add-timestamp", required_argument, 0, 'a'},
{"hexdump", 0, 0, 'x'},
{"rawdump", required_argument, 0, 'r'},
{"file", required_argument, 0, 'f'},
{"verbose", 0, 0, 'V'},
{"version", 0, 0, 'v'},
{"help", 0, 0, 'h'},
{0, 0, 0, 0}
};
while ((opt = getopt_long(argc, argv, "c12B:CltTSa:LxVvh?r:",
while ((opt = getopt_long(argc, argv, "c12B:CltTSa:LxVvh?r:f:",
long_options, &option_index)) != EOF) {
switch (opt) {
case 'c':
Expand Down Expand Up @@ -1539,6 +1582,14 @@ int main(int argc, char** argv)
print_defaults = 0;
rawdump_id = strtoul(optarg, NULL, 16);
break;
case 'f':
file_fd = open(optarg, O_RDONLY, 0);
if (file_fd < 0) {
fprintf(stderr, "Failed to open file '%s': %s\n",
optarg, strerror(errno));
return 1;
}
break;
case 't':
timestamp_type = TIMESTAMPS_PRINT_NORMAL;
print_defaults = 0;
Expand Down Expand Up @@ -1580,11 +1631,13 @@ int main(int argc, char** argv)
print_usage(argv[0], 1);
}

mem_fd = open("/dev/mem", timestamp_id ? O_RDWR : O_RDONLY, 0);
if (mem_fd < 0) {
fprintf(stderr, "Failed to gain memory access: %s\n",
strerror(errno));
return 1;
if (file_fd < 0) {
mem_fd = open("/dev/mem", timestamp_id ? O_RDWR : O_RDONLY, 0);
if (mem_fd < 0) {
fprintf(stderr, "Failed to gain memory access: %s\n",
strerror(errno));
return 1;
}
}

#if defined(__arm__) || defined(__aarch64__)
Expand Down Expand Up @@ -1681,6 +1734,10 @@ int main(int argc, char** argv)

unmap_memory(&lbtable_mapping);

close(mem_fd);
if (file_fd >= 0)
close(file_fd);
if (mem_fd >= 0)
close(mem_fd);

return 0;
}

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