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[fdt] Allow for the existence of multiple device trees 

When running on a platform that uses FDT as its hardware description
mechanism, we are likely to have multiple device tree structures.  At
a minimum, there will be the device tree passed to us from the
previous boot stage (e.g. OpenSBI), and the device tree that we
construct to be passed to the booted operating system.

Update the internal FDT API to include an FDT pointer in all function
parameter lists.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
pull/1437/head
Michael Brown 2025-03-28 12:42:30 +00:00
parent 09fbebc084
commit 2399c79980
7 changed files with 120 additions and 109 deletions
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4
src/arch/riscv/core/hart.c
View File

@ -55,7 +55,7 @@ static int hart_node ( unsigned int *offset ) {
snprintf ( path, sizeof ( path ), "/cpus/cpu@%lx", boot_hart );
/* Find node */
if ( ( rc = fdt_path ( path, offset ) ) != 0 ) {
if ( ( rc = fdt_path ( &sysfdt, path, offset ) ) != 0 ) {
DBGC ( colour, "HART could not find %s: %s\n",
path, strerror ( rc ) );
return rc;
@ -81,7 +81,7 @@ int hart_supported ( const char *ext ) {
return rc;
/* Get ISA description */
isa = fdt_string ( offset, "riscv,isa" );
isa = fdt_string ( &sysfdt, offset, "riscv,isa" );
if ( ! isa ) {
DBGC ( colour, "HART could not identify ISA\n" );
return -ENOENT;

4
src/arch/riscv/core/zicntr.c
View File

@ -152,8 +152,8 @@ static int zicntr_probe ( void ) {
}
/* Get timer frequency */
if ( ( ( rc = fdt_path ( "/cpus", &offset ) ) != 0 ) ||
( ( rc = fdt_u64 ( offset, "timebase-frequency",
if ( ( ( rc = fdt_path ( &sysfdt, "/cpus", &offset ) ) != 0 ) ||
( ( rc = fdt_u64 ( &sysfdt, offset, "timebase-frequency",
&u.freq ) ) != 0 ) ) {
DBGC ( colour, "ZICNTR could not determine frequency: %s\n",
strerror ( rc ) );

5
src/arch/riscv/prefix/sbiprefix.S
View File

@ -121,8 +121,9 @@ _sbi_start:
STOREN s0, (t0)
/* Register device tree */
mv a0, s1
call register_fdt
la a0, sysfdt
mv a1, s1
call fdt_parse
/* Call main program */
progress "\n\n"

186
src/core/fdt.c
View File

@ -38,7 +38,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
*/
/** The system flattened device tree (if present) */
static struct fdt fdt;
struct fdt sysfdt;
/** The downloaded flattened device tree tag */
struct image_tag fdt_image __image_tag = {
@ -63,24 +63,16 @@ struct fdt_descriptor {
size_t len;
};
/**
* Check if device tree exists
*
* @v has_fdt Device tree exists
*/
static inline __attribute__ (( always_inline )) int fdt_exists ( void ) {
return ( fdt.hdr != NULL );
}
/**
* Traverse device tree
*
* @v fdt Device tree
* @v pos Position within device tree
* @v desc Lexical descriptor to fill in
* @ret rc Return status code
*/
static int fdt_traverse ( struct fdt_cursor *pos,
static int fdt_traverse ( struct fdt *fdt,
struct fdt_cursor *pos,
struct fdt_descriptor *desc ) {
const fdt_token_t *token;
const void *data;
@ -90,17 +82,17 @@ static int fdt_traverse ( struct fdt_cursor *pos,
size_t len;
/* Sanity checks */
assert ( pos->offset < fdt.len );
assert ( pos->offset < fdt->len );
assert ( ( pos->offset & ( FDT_STRUCTURE_ALIGN - 1 ) ) == 0 );
/* Clear descriptor */
memset ( desc, 0, sizeof ( *desc ) );
/* Locate token and calculate remaining space */
token = ( fdt.raw + fdt.structure + pos->offset );
remaining = ( fdt.len - pos->offset );
token = ( fdt->raw + fdt->structure + pos->offset );
remaining = ( fdt->len - pos->offset );
if ( remaining < sizeof ( *token ) ) {
DBGC ( &fdt, "FDT truncated tree at +%#04x\n", pos->offset );
DBGC ( fdt, "FDT truncated tree at +%#04x\n", pos->offset );
return -EINVAL;
}
remaining -= sizeof ( *token );
@ -116,7 +108,7 @@ static int fdt_traverse ( struct fdt_cursor *pos,
desc->name = data;
len = ( strnlen ( desc->name, remaining ) + 1 /* NUL */ );
if ( remaining < len ) {
DBGC ( &fdt, "FDT unterminated node name at +%#04x\n",
DBGC ( fdt, "FDT unterminated node name at +%#04x\n",
pos->offset );
return -EINVAL;
}
@ -127,7 +119,7 @@ static int fdt_traverse ( struct fdt_cursor *pos,
/* End of node */
if ( pos->depth < 0 ) {
DBGC ( &fdt, "FDT spurious node end at +%#04x\n",
DBGC ( fdt, "FDT spurious node end at +%#04x\n",
pos->offset );
return -EINVAL;
}
@ -143,7 +135,7 @@ static int fdt_traverse ( struct fdt_cursor *pos,
/* Property */
prop = data;
if ( remaining < sizeof ( *prop ) ) {
DBGC ( &fdt, "FDT truncated property at +%#04x\n",
DBGC ( fdt, "FDT truncated property at +%#04x\n",
pos->offset );
return -EINVAL;
}
@ -151,17 +143,17 @@ static int fdt_traverse ( struct fdt_cursor *pos,
desc->len = be32_to_cpu ( prop->len );
len = ( sizeof ( *prop ) + desc->len );
if ( remaining < len ) {
DBGC ( &fdt, "FDT overlength property at +%#04x\n",
DBGC ( fdt, "FDT overlength property at +%#04x\n",
pos->offset );
return -EINVAL;
}
name_off = be32_to_cpu ( prop->name_off );
if ( name_off > fdt.strings_len ) {
DBGC ( &fdt, "FDT property name outside strings "
if ( name_off > fdt->strings_len ) {
DBGC ( fdt, "FDT property name outside strings "
"block at +%#04x\n", pos->offset );
return -EINVAL;
}
desc->name = ( fdt.raw + fdt.strings + name_off );
desc->name = ( fdt->raw + fdt->strings + name_off );
break;
case cpu_to_be32 ( FDT_NOP ):
@ -172,7 +164,7 @@ static int fdt_traverse ( struct fdt_cursor *pos,
default:
/* Unrecognised or unexpected token */
DBGC ( &fdt, "FDT unexpected token %#08x at +%#04x\n",
DBGC ( fdt, "FDT unexpected token %#08x at +%#04x\n",
be32_to_cpu ( *token ), pos->offset );
return -EINVAL;
}
@ -183,7 +175,7 @@ static int fdt_traverse ( struct fdt_cursor *pos,
pos->offset += ( sizeof ( *token ) + len );
/* Sanity checks */
assert ( pos->offset <= fdt.len );
assert ( pos->offset <= fdt->len );
return 0;
}
@ -191,12 +183,13 @@ static int fdt_traverse ( struct fdt_cursor *pos,
/**
* Find child node
*
* @v fdt Device tree
* @v offset Starting node offset
* @v name Node name
* @v child Child node offset to fill in
* @ret rc Return status code
*/
static int fdt_child ( unsigned int offset, const char *name,
static int fdt_child ( struct fdt *fdt, unsigned int offset, const char *name,
unsigned int *child ) {
struct fdt_cursor pos;
struct fdt_descriptor desc;
@ -217,18 +210,18 @@ static int fdt_child ( unsigned int offset, const char *name,
*child = pos.offset;
/* Traverse tree */
if ( ( rc = fdt_traverse ( &pos, &desc ) ) != 0 ) {
DBGC ( &fdt, "FDT +%#04x has no child node \"%s\": "
if ( ( rc = fdt_traverse ( fdt, &pos, &desc ) ) != 0 ) {
DBGC ( fdt, "FDT +%#04x has no child node \"%s\": "
"%s\n", orig_offset, name, strerror ( rc ) );
return rc;
}
/* Check for matching immediate child node */
if ( ( pos.depth == 1 ) && desc.name && ( ! desc.data ) ) {
DBGC2 ( &fdt, "FDT +%#04x has child node \"%s\"\n",
DBGC2 ( fdt, "FDT +%#04x has child node \"%s\"\n",
orig_offset, desc.name );
if ( strcmp ( name, desc.name ) == 0 ) {
DBGC2 ( &fdt, "FDT +%#04x found child node "
DBGC2 ( fdt, "FDT +%#04x found child node "
"\"%s\" at +%#04x\n", orig_offset,
desc.name, *child );
return 0;
@ -240,11 +233,12 @@ static int fdt_child ( unsigned int offset, const char *name,
/**
* Find node by path
*
* @v fdt Device tree
* @v path Node path
* @v offset Offset to fill in
* @ret rc Return status code
*/
int fdt_path ( const char *path, unsigned int *offset ) {
int fdt_path ( struct fdt *fdt, const char *path, unsigned int *offset ) {
char *tmp = ( ( char * ) path );
char *del;
int rc;
@ -265,7 +259,7 @@ int fdt_path ( const char *path, unsigned int *offset ) {
*del = '\0';
/* Find child and restore delimiter */
rc = fdt_child ( *offset, tmp, offset );
rc = fdt_child ( fdt, *offset, tmp, offset );
if ( del )
*del = '/';
if ( rc != 0 )
@ -276,32 +270,33 @@ int fdt_path ( const char *path, unsigned int *offset ) {
tmp++;
}
DBGC2 ( &fdt, "FDT found path \"%s\" at +%#04x\n", path, *offset );
DBGC2 ( fdt, "FDT found path \"%s\" at +%#04x\n", path, *offset );
return 0;
}
/**
* Find node by alias
*
* @v fdt Device tree
* @v name Alias name
* @v offset Offset to fill in
* @ret rc Return status code
*/
int fdt_alias ( const char *name, unsigned int *offset ) {
int fdt_alias ( struct fdt *fdt, const char *name, unsigned int *offset ) {
const char *alias;
int rc;
/* Locate "/aliases" node */
if ( ( rc = fdt_child ( 0, "aliases", offset ) ) != 0 )
if ( ( rc = fdt_child ( fdt, 0, "aliases", offset ) ) != 0 )
return rc;
/* Locate alias property */
if ( ( alias = fdt_string ( *offset, name ) ) == NULL )
if ( ( alias = fdt_string ( fdt, *offset, name ) ) == NULL )
return -ENOENT;
DBGC ( &fdt, "FDT alias \"%s\" is \"%s\"\n", name, alias );
DBGC ( fdt, "FDT alias \"%s\" is \"%s\"\n", name, alias );
/* Locate aliased node */
if ( ( rc = fdt_path ( alias, offset ) ) != 0 )
if ( ( rc = fdt_path ( fdt, alias, offset ) ) != 0 )
return rc;
return 0;
@ -310,13 +305,14 @@ int fdt_alias ( const char *name, unsigned int *offset ) {
/**
* Find property
*
* @v fdt Device tree
* @v offset Starting node offset
* @v name Property name
* @v desc Lexical descriptor to fill in
* @ret rc Return status code
*/
static int fdt_property ( unsigned int offset, const char *name,
struct fdt_descriptor *desc ) {
static int fdt_property ( struct fdt *fdt, unsigned int offset,
const char *name, struct fdt_descriptor *desc ) {
struct fdt_cursor pos;
int rc;
@ -328,20 +324,20 @@ static int fdt_property ( unsigned int offset, const char *name,
while ( 1 ) {
/* Traverse tree */
if ( ( rc = fdt_traverse ( &pos, desc ) ) != 0 ) {
DBGC ( &fdt, "FDT +%#04x has no property \"%s\": %s\n",
if ( ( rc = fdt_traverse ( fdt, &pos, desc ) ) != 0 ) {
DBGC ( fdt, "FDT +%#04x has no property \"%s\": %s\n",
offset, name, strerror ( rc ) );
return rc;
}
/* Check for matching immediate child property */
if ( ( pos.depth == 0 ) && desc->data ) {
DBGC2 ( &fdt, "FDT +%#04x has property \"%s\" len "
DBGC2 ( fdt, "FDT +%#04x has property \"%s\" len "
"%#zx\n", offset, desc->name, desc->len );
if ( strcmp ( name, desc->name ) == 0 ) {
DBGC2 ( &fdt, "FDT +%#04x found property "
DBGC2 ( fdt, "FDT +%#04x found property "
"\"%s\"\n", offset, desc->name );
DBGC2_HDA ( &fdt, 0, desc->data, desc->len );
DBGC2_HDA ( fdt, 0, desc->data, desc->len );
return 0;
}
}
@ -351,21 +347,23 @@ static int fdt_property ( unsigned int offset, const char *name,
/**
* Find string property
*
* @v fdt Device tree
* @v offset Starting node offset
* @v name Property name
* @ret string String property, or NULL on error
*/
const char * fdt_string ( unsigned int offset, const char *name ) {
const char * fdt_string ( struct fdt *fdt, unsigned int offset,
const char *name ) {
struct fdt_descriptor desc;
int rc;
/* Find property */
if ( ( rc = fdt_property ( offset, name, &desc ) ) != 0 )
if ( ( rc = fdt_property ( fdt, offset, name, &desc ) ) != 0 )
return NULL;
/* Check NUL termination */
if ( strnlen ( desc.data, desc.len ) == desc.len ) {
DBGC ( &fdt, "FDT unterminated string property \"%s\"\n",
DBGC ( fdt, "FDT unterminated string property \"%s\"\n",
name );
return NULL;
}
@ -376,12 +374,14 @@ const char * fdt_string ( unsigned int offset, const char *name ) {
/**
* Find integer property
*
* @v fdt Device tree
* @v offset Starting node offset
* @v name Property name
* @v value Integer value to fill in
* @ret rc Return status code
*/
int fdt_u64 ( unsigned int offset, const char *name, uint64_t *value ) {
int fdt_u64 ( struct fdt *fdt, unsigned int offset, const char *name,
uint64_t *value ) {
struct fdt_descriptor desc;
const uint8_t *data;
size_t remaining;
@ -391,12 +391,12 @@ int fdt_u64 ( unsigned int offset, const char *name, uint64_t *value ) {
*value = 0;
/* Find property */
if ( ( rc = fdt_property ( offset, name, &desc ) ) != 0 )
if ( ( rc = fdt_property ( fdt, offset, name, &desc ) ) != 0 )
return rc;
/* Check range */
if ( desc.len > sizeof ( *value ) ) {
DBGC ( &fdt, "FDT oversized integer property \"%s\"\n", name );
DBGC ( fdt, "FDT oversized integer property \"%s\"\n", name );
return -ERANGE;
}
@ -414,18 +414,21 @@ int fdt_u64 ( unsigned int offset, const char *name, uint64_t *value ) {
/**
* Get MAC address from property
*
* @v fdt Device tree
* @v offset Starting node offset
* @v netdev Network device
* @ret rc Return status code
*/
int fdt_mac ( unsigned int offset, struct net_device *netdev ) {
int fdt_mac ( struct fdt *fdt, unsigned int offset,
struct net_device *netdev ) {
struct fdt_descriptor desc;
size_t len;
int rc;
/* Find applicable MAC address property */
if ( ( ( rc = fdt_property ( offset, "mac-address", &desc ) ) != 0 ) &&
( ( rc = fdt_property ( offset, "local-mac-address",
if ( ( ( rc = fdt_property ( fdt, offset, "mac-address",
&desc ) ) != 0 ) &&
( ( rc = fdt_property ( fdt, offset, "local-mac-address",
&desc ) ) != 0 ) ) {
return rc;
}
@ -433,9 +436,9 @@ int fdt_mac ( unsigned int offset, struct net_device *netdev ) {
/* Check length */
len = netdev->ll_protocol->hw_addr_len;
if ( len != desc.len ) {
DBGC ( &fdt, "FDT malformed MAC address \"%s\":\n",
DBGC ( fdt, "FDT malformed MAC address \"%s\":\n",
desc.name );
DBGC_HDA ( &fdt, 0, desc.data, desc.len );
DBGC_HDA ( fdt, 0, desc.data, desc.len );
return -ERANGE;
}
@ -446,85 +449,86 @@ int fdt_mac ( unsigned int offset, struct net_device *netdev ) {
}
/**
* Register device tree
* Parse device tree
*
* @v fdt Device tree header
* @v fdt Device tree
* @v hdr Device tree header
* @ret rc Return status code
*/
int register_fdt ( const struct fdt_header *hdr ) {
int fdt_parse ( struct fdt *fdt, const struct fdt_header *hdr ) {
const uint8_t *end;
/* Record device tree location */
fdt.hdr = hdr;
fdt.len = be32_to_cpu ( hdr->totalsize );
DBGC ( &fdt, "FDT version %d at %p+%#04zx\n",
be32_to_cpu ( hdr->version ), fdt.hdr, fdt.len );
fdt->hdr = hdr;
fdt->len = be32_to_cpu ( hdr->totalsize );
DBGC ( fdt, "FDT version %d at %p+%#04zx\n",
be32_to_cpu ( hdr->version ), fdt->hdr, fdt->len );
/* Check signature */
if ( hdr->magic != cpu_to_be32 ( FDT_MAGIC ) ) {
DBGC ( &fdt, "FDT has invalid magic value %#08x\n",
DBGC ( fdt, "FDT has invalid magic value %#08x\n",
be32_to_cpu ( hdr->magic ) );
goto err;
}
/* Check version */
if ( hdr->last_comp_version != cpu_to_be32 ( FDT_VERSION ) ) {
DBGC ( &fdt, "FDT unsupported version %d\n",
DBGC ( fdt, "FDT unsupported version %d\n",
be32_to_cpu ( hdr->last_comp_version ) );
goto err;
}
/* Record structure block location */
fdt.structure = be32_to_cpu ( hdr->off_dt_struct );
fdt.structure_len = be32_to_cpu ( hdr->size_dt_struct );
DBGC ( &fdt, "FDT structure block at +[%#04x,%#04zx)\n",
fdt.structure, ( fdt.structure + fdt.structure_len ) );
if ( ( fdt.structure > fdt.len ) ||
( fdt.structure_len > ( fdt.len - fdt.structure ) ) ) {
DBGC ( &fdt, "FDT structure block exceeds table\n" );
fdt->structure = be32_to_cpu ( hdr->off_dt_struct );
fdt->structure_len = be32_to_cpu ( hdr->size_dt_struct );
DBGC ( fdt, "FDT structure block at +[%#04x,%#04zx)\n",
fdt->structure, ( fdt->structure + fdt->structure_len ) );
if ( ( fdt->structure > fdt->len ) ||
( fdt->structure_len > ( fdt->len - fdt->structure ) ) ) {
DBGC ( fdt, "FDT structure block exceeds table\n" );
goto err;
}
if ( ( fdt.structure | fdt.structure_len ) &
if ( ( fdt->structure | fdt->structure_len ) &
( FDT_STRUCTURE_ALIGN - 1 ) ) {
DBGC ( &fdt, "FDT structure block is misaligned\n" );
DBGC ( fdt, "FDT structure block is misaligned\n" );
goto err;
}
/* Record strings block location */
fdt.strings = be32_to_cpu ( hdr->off_dt_strings );
fdt.strings_len = be32_to_cpu ( hdr->size_dt_strings );
DBGC ( &fdt, "FDT strings block at +[%#04x,%#04zx)\n",
fdt.strings, ( fdt.strings + fdt.strings_len ) );
if ( ( fdt.strings > fdt.len ) ||
( fdt.strings_len > ( fdt.len - fdt.strings ) ) ) {
DBGC ( &fdt, "FDT strings block exceeds table\n" );
fdt->strings = be32_to_cpu ( hdr->off_dt_strings );
fdt->strings_len = be32_to_cpu ( hdr->size_dt_strings );
DBGC ( fdt, "FDT strings block at +[%#04x,%#04zx)\n",
fdt->strings, ( fdt->strings + fdt->strings_len ) );
if ( ( fdt->strings > fdt->len ) ||
( fdt->strings_len > ( fdt->len - fdt->strings ) ) ) {
DBGC ( fdt, "FDT strings block exceeds table\n" );
goto err;
}
/* Shrink strings block to ensure NUL termination safety */
end = ( fdt.raw + fdt.strings + fdt.strings_len );
for ( ; fdt.strings_len ; fdt.strings_len-- ) {
end = ( fdt->raw + fdt->strings + fdt->strings_len );
for ( ; fdt->strings_len ; fdt->strings_len-- ) {
if ( *(--end) == '\0' )
break;
}
if ( fdt.strings_len != be32_to_cpu ( hdr->size_dt_strings ) ) {
DBGC ( &fdt, "FDT strings block shrunk to +[%#04x,%#04zx)\n",
fdt.strings, ( fdt.strings + fdt.strings_len ) );
if ( fdt->strings_len != be32_to_cpu ( hdr->size_dt_strings ) ) {
DBGC ( fdt, "FDT strings block shrunk to +[%#04x,%#04zx)\n",
fdt->strings, ( fdt->strings + fdt->strings_len ) );
}
/* Print model name (for debugging) */
DBGC ( &fdt, "FDT model is \"%s\"\n", fdt_string ( 0, "model" ) );
DBGC ( fdt, "FDT model is \"%s\"\n", fdt_string ( fdt, 0, "model" ) );
return 0;
err:
DBGC_HDA ( &fdt, 0, hdr, sizeof ( *hdr ) );
fdt.hdr = NULL;
DBGC_HDA ( fdt, 0, hdr, sizeof ( *hdr ) );
memset ( fdt, 0, sizeof ( *fdt ) );
return -EINVAL;
}
/* Drag in objects via register_fdt */
REQUIRING_SYMBOL ( register_fdt );
/* Drag in objects via fdt_traverse() */
REQUIRING_SYMBOL ( fdt_traverse );
/* Drag in device tree configuration */
REQUIRE_OBJECT ( config_fdt );

6
src/drivers/net/smscusb.c
View File

@ -459,13 +459,13 @@ int smscusb_fdt_fetch_mac ( struct smscusb_device *smscusb ) {
int rc;
/* Look for "ethernet[0]" alias */
if ( ( rc = fdt_alias ( "ethernet", &offset ) != 0 ) &&
( rc = fdt_alias ( "ethernet0", &offset ) != 0 ) ) {
if ( ( rc = fdt_alias ( &sysfdt, "ethernet", &offset ) != 0 ) &&
( rc = fdt_alias ( &sysfdt, "ethernet0", &offset ) != 0 ) ) {
return rc;
}
/* Fetch MAC address */
if ( ( rc = fdt_mac ( offset, netdev ) ) != 0 )
if ( ( rc = fdt_mac ( &sysfdt, offset, netdev ) ) != 0 )
return rc;
DBGC ( smscusb, "SMSCUSB %p using FDT MAC %s\n",

18
src/include/ipxe/fdt.h
View File

@ -95,12 +95,18 @@ struct fdt {
};
extern struct image_tag fdt_image __image_tag;
extern struct fdt sysfdt;
extern int fdt_path ( const char *path, unsigned int *offset );
extern int fdt_alias ( const char *name, unsigned int *offset );
extern const char * fdt_string ( unsigned int offset, const char *name );
extern int fdt_u64 ( unsigned int offset, const char *name, uint64_t *value );
extern int fdt_mac ( unsigned int offset, struct net_device *netdev );
extern int register_fdt ( const struct fdt_header *hdr );
extern int fdt_path ( struct fdt *fdt, const char *path,
unsigned int *offset );
extern int fdt_alias ( struct fdt *fdt, const char *name,
unsigned int *offset );
extern const char * fdt_string ( struct fdt *fdt, unsigned int offset,
const char *name );
extern int fdt_u64 ( struct fdt *fdt, unsigned int offset, const char *name,
uint64_t *value );
extern int fdt_mac ( struct fdt *fdt, unsigned int offset,
struct net_device *netdev );
extern int fdt_parse ( struct fdt *fdt, const struct fdt_header *hdr );
#endif /* _IPXE_FDT_H */

6
src/interface/efi/efi_fdt.c
View File

@ -53,9 +53,9 @@ static void efi_fdt_init ( void ) {
}
DBGC ( &efi_fdt, "EFIFDT configuration table at %p\n", efi_fdt );
/* Register device tree */
if ( ( rc = register_fdt ( efi_fdt ) ) != 0 ) {
DBGC ( &efi_fdt, "EFIFDT could not register: %s\n",
/* Parse as system device tree */
if ( ( rc = fdt_parse ( &sysfdt, efi_fdt ) ) != 0 ) {
DBGC ( &efi_fdt, "EFIFDT could not parse: %s\n",
strerror ( rc ) );
return;
}