int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
{
const char *end = path + namelen;
const char *p = path;
int offset = 0;
FDT_CHECK_HEADER(fdt);
/* see if we have an alias */
if (*path != '/') {
const char *q = fdt_path_next_separator(path, namelen);
if (!q)
q = end;
p = fdt_get_alias_namelen(fdt, p, q - p);
if (!p)
return -FDT_ERR_BADPATH;
offset = fdt_path_offset(fdt, p);
p = q;
}
while (*p && (p < end)) {
const char *q;
while (*p == '/')
p++;
if (*p == '\0' || *p == ':')
return offset;
q = fdt_path_next_separator(p, end - p);
if (!q)
q = end;
offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
if (offset < 0)
return offset;
p = q;
}
return offset;
}
int fdt_path_offset(const void *fdt, const char *path)
{
const char *end = path + strlen(path);
const char *p = path;
int offset = 0;
FDT_CHECK_HEADER(fdt);
/* see if we have an alias */
if (*path != '/') {
const char *q = strchr(path, '/');
if (!q)
q = end;
p = fdt_get_alias_namelen(fdt, p, q - p);
if (!p)
return -FDT_ERR_BADPATH;
offset = fdt_path_offset(fdt, p);
p = q;
}
while (*p) {
const char *q;
while (*p == '/')
p++;
if (! *p)
return offset;
q = strchr(p, '/');
if (! q)
q = end;
offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
if (offset < 0)
return offset;
p = q;
}
return offset;
}
static int serial_check_stdout(const void *blob, struct udevice **devp)
{
int node;
/* Check for a chosen console */
node = fdtdec_get_chosen_node(blob, "stdout-path");
if (node < 0) {
const char *str, *p, *name;
/*
* Deal with things like
* stdout-path = "serial0:115200n8";
*
* We need to look up the alias and then follow it to the
* correct node.
*/
str = fdtdec_get_chosen_prop(blob, "stdout-path");
if (str) {
p = strchr(str, ':');
name = fdt_get_alias_namelen(blob, str,
p ? p - str : strlen(str));
if (name)
node = fdt_path_offset(blob, name);
}
}
if (node < 0)
node = fdt_path_offset(blob, "console");
if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
return 0;
/*
* If the console is not marked to be bound before relocation, bind it
* anyway.
*/
if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
devp)) {
if (!device_probe(*devp))
return 0;
}
return -ENODEV;
}
const char *fdt_get_alias(const void *fdt, const char *name)
{
return fdt_get_alias_namelen(fdt, name, strlen(name));
}
static void serial_find_console_or_panic(void)
{
const void *blob = gd->fdt_blob;
struct udevice *dev;
int node;
if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
/* Check for a chosen console */
node = fdtdec_get_chosen_node(blob, "stdout-path");
if (node < 0) {
const char *str, *p, *name;
/*
* Deal with things like
* stdout-path = "serial0:115200n8";
*
* We need to look up the alias and then follow it to
* the correct node.
*/
str = fdtdec_get_chosen_prop(blob, "stdout-path");
if (str) {
p = strchr(str, ':');
name = fdt_get_alias_namelen(blob, str,
p ? p - str : strlen(str));
if (name)
node = fdt_path_offset(blob, name);
}
}
if (node < 0)
node = fdt_path_offset(blob, "console");
if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node,
&dev)) {
gd->cur_serial_dev = dev;
return;
}
/*
* If the console is not marked to be bound before relocation,
* bind it anyway.
*/
if (node > 0 &&
!lists_bind_fdt(gd->dm_root, blob, node, &dev)) {
if (!device_probe(dev)) {
gd->cur_serial_dev = dev;
return;
}
}
}
if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
/*
* Try to use CONFIG_CONS_INDEX if available (it is numbered
* from 1!).
*
* Failing that, get the device with sequence number 0, or in
* extremis just the first serial device we can find. But we
* insist on having a console (even if it is silent).
*/
#ifdef CONFIG_CONS_INDEX
#define INDEX (CONFIG_CONS_INDEX - 1)
#else
#define INDEX 0
#endif
if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
!uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
(!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
gd->cur_serial_dev = dev;
return;
}
#undef INDEX
}
#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
panic_str("No serial driver found");
#endif
}
/*
* chosen {
* bootargs = "console=ttyS0,115200 ubi.mtd=4 root=ubi0:rootfs rootfstype=ubifs";
* };
* 호출: int offset = fdt_path_offset(fdt, "/chosen");
*/
int fdt_path_offset(const void *fdt, const char *path)
{
/*
* p : "chosen"의 시작 주소
* end : "chosen"의 끝 주소
*/
const char *end = path + strlen(path);
const char *p = path;
int offset = 0;
FDT_CHECK_HEADER(fdt);
/* see if we have an alias */
if (*path != '/') {
// path가 '/'로 시작하지 않으면 path내에서 '/' 위치 찾음
const char *q = strchr(path, '/');
// path내에 '/'가 없으면 끝 주소로 지정
if (!q)
q = end;
/*
* '/'로 시작하지 않았다면 alias라고 가정하고 원래 node명 탐색
* p: alias명
* q-p: alias 길이
*/
p = fdt_get_alias_namelen(fdt, p, q - p);
// alias도 아닌경우 에러 리턴
if (!p)
return -FDT_ERR_BADPATH;
offset = fdt_path_offset(fdt, p);
p = q;
}
/*
* "chosen"의 alias가 없으면 여기서 탐색
* 여기서는 node의 이름이 "chosen"인지 아닌지 탐색
*/
while (*p) {
const char *q;
// path내에서 '/'가 아닌곳까지 이동
while (*p == '/')
p++;
// path 끝까지 이동한 경우
if (! *p)
return offset;
// p를 기준으로 다음 '/' 위치까지 찾아서
q = strchr(p, '/');
// 다음 '/'가 없다면 path의 끝으로 지정
if (! q)
q = end;
// path에서 '/'로 split 해보면서
// 하위 node들중 해당 이름의 node가 있는지 탐색
offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
if (offset < 0)
return offset;
p = q;
}
return offset;
}