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dtc: Add support for variable sized elements

Elements of size 8, 16, 32, and 64 bits are supported.  The new
/bits/ syntax was selected so as to not pollute the reserved
keyword space with uint8/uint16/... type names.

With this patch the following property assignment:

    property = /bits/ 16 <0x1234 0x5678 0x0 0xffff>;

is equivalent to:

    property = <0x12345678 0x0000ffff>;

It is now also possible to directly specify a 64 bit literal in a
cell list, also known as an array using:

    property = /bits/ 64 <0xdeadbeef00000000>;

It is an error to attempt to store a literal into an element that is
too small to hold the literal, and the compiler will generate an
error when it detects this.  For instance:

    property = /bits/ 8 <256>;

Will fail to compile.  It is also an error to attempt to place a
reference in a non 32-bit element.

The documentation has been changed to reflect that the cell list
is now an array of elements that can be of sizes other than the
default 32-bit cell size.

The sized_cells test tests the creation and access of 8, 16, 32,
and 64-bit sized elements.  It also tests that the creation of two
properties, one with 16 bit elements and one with 32 bit elements
result in the same property contents.

Signed-off-by: Anton Staaf <robotboy@chromium.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
main
Anton Staaf 13 years ago committed by Jon Loeliger
parent
commit
033089f290
  1. 34
      Documentation/dts-format.txt
  2. 6
      dtc-lexer.l
  3. 70
      dtc-parser.y
  4. 1
      tests/.gitignore
  5. 1
      tests/Makefile.tests
  6. 3
      tests/run_tests.sh
  7. 84
      tests/sized_cells.c
  8. 11
      tests/sized_cells.dts

34
Documentation/dts-format.txt

@ -29,18 +29,28 @@ except for properties with empty (zero length) value which have the @@ -29,18 +29,28 @@ except for properties with empty (zero length) value which have the
form:
[label:] property-name;

Property values may be defined as an array of 32-bit integer cells, as
NUL-terminated strings, as bytestrings or a combination of these.
Property values may be defined as an array of 8, 16, 32, or 64-bit integer
elements, as NUL-terminated strings, as bytestrings or a combination of these.

* Arrays of cells are represented by angle brackets surrounding a
space separated list of C-style integers or character literals.
* Arrays are represented by angle brackets surrounding a space separated list
of C-style integers or character literals. Array elements default to 32-bits
in size. An array of 32-bit elements is also known as a cell list or a list
of cells. A cell being an unsigned 32-bit integer.

e.g. interrupts = <17 0xc>;

* A 64-bit value is represented with two 32-bit cells.
* A 64-bit value can be represented with two 32-bit elements.

e.g. clock-frequency = <0x00000001 0x00000000>;

* The storage size of an element can be changed using the /bits/ prefix. The
/bits/ prefix allows for the creation of 8, 16, 32, and 64-bit elements.
The resulting array will not be padded to a multiple of the default 32-bit
element size.

e.g. interrupts = /bits/ 8 <17 0xc>;
e.g. clock-frequency = /bits/ 64 <0x0000000100000000>;

* A NUL-terminated string value is represented using double quotes
(the property value is considered to include the terminating NUL
character).
@ -59,19 +69,20 @@ NUL-terminated strings, as bytestrings or a combination of these. @@ -59,19 +69,20 @@ NUL-terminated strings, as bytestrings or a combination of these.
e.g. compatible = "ns16550", "ns8250";
example = <0xf00f0000 19>, "a strange property format";

* In a cell array a reference to another node will be expanded to that
node's phandle. References may by '&' followed by a node's label:
* In an array a reference to another node will be expanded to that node's
phandle. References may by '&' followed by a node's label:
e.g. interrupt-parent = < &mpic >;
or they may be '&' followed by a node's full path in braces:
e.g. interrupt-parent = < &{/soc/interrupt-controller@40000} >;
References are only permitted in arrays that have an element size of
32-bits.

* Outside a cell array, a reference to another node will be expanded
to that node's full path.
* Outside an array, a reference to another node will be expanded to that
node's full path.
e.g. ethernet0 = &EMAC0;

* Labels may also appear before or after any component of a property
value, or between cells of a cell array, or between bytes of a
bytestring.
value, or between elements of an array, or between bytes of a bytestring.
e.g. reg = reglabel: <0 sizelabel: 0x1000000>;
e.g. prop = [ab cd ef byte4: 00 ff fe];
e.g. str = start: "string value" end: ;
@ -108,3 +119,4 @@ Version 1 DTS files have the overall layout: @@ -108,3 +119,4 @@ Version 1 DTS files have the overall layout:

-- David Gibson <david@gibson.dropbear.id.au>
-- Yoder Stuart <stuart.yoder@freescale.com>
-- Anton Staaf <robotboy@chromium.org>

6
dtc-lexer.l

@ -97,6 +97,12 @@ static int pop_input_file(void); @@ -97,6 +97,12 @@ static int pop_input_file(void);
return DT_MEMRESERVE;
}

<*>"/bits/" {
DPRINT("Keyword: /bits/\n");
BEGIN_DEFAULT();
return DT_BITS;
}

<*>{LABEL}: {
DPRINT("Label: %s\n", yytext);
yylval.labelref = xstrdup(yytext);

70
dtc-parser.y

@ -45,8 +45,12 @@ static unsigned char eval_char_literal(const char *s); @@ -45,8 +45,12 @@ static unsigned char eval_char_literal(const char *s);
uint8_t byte;
struct data data;

struct {
struct data data;
int bits;
} array;

uint64_t addr;
cell_t cell;
struct property *prop;
struct property *proplist;
struct node *node;
@ -56,6 +60,7 @@ static unsigned char eval_char_literal(const char *s); @@ -56,6 +60,7 @@ static unsigned char eval_char_literal(const char *s);

%token DT_V1
%token DT_MEMRESERVE
%token DT_BITS
%token <propnodename> DT_PROPNODENAME
%token <literal> DT_LITERAL
%token <literal> DT_CHAR_LITERAL
@ -71,8 +76,7 @@ static unsigned char eval_char_literal(const char *s); @@ -71,8 +76,7 @@ static unsigned char eval_char_literal(const char *s);
%type <re> memreserve
%type <re> memreserves
%type <addr> addr
%type <data> celllist
%type <cell> cellval
%type <array> arrayprefix
%type <data> bytestring
%type <prop> propdef
%type <proplist> proplist
@ -182,9 +186,9 @@ propdata: @@ -182,9 +186,9 @@ propdata:
{
$$ = data_merge($1, $2);
}
| propdataprefix '<' celllist '>'
| propdataprefix arrayprefix '>'
{
$$ = data_merge($1, $3);
$$ = data_merge($1, $2.data);
}
| propdataprefix '[' bytestring ']'
{
@ -242,34 +246,56 @@ propdataprefix: @@ -242,34 +246,56 @@ propdataprefix:
}
;

celllist:
/* empty */
arrayprefix:
DT_BITS DT_LITERAL '<'
{
$$ = empty_data;
$$.data = empty_data;
$$.bits = eval_literal($2, 0, 7);

if (($$.bits != 8) &&
($$.bits != 16) &&
($$.bits != 32) &&
($$.bits != 64))
{
print_error("Only 8, 16, 32 and 64-bit elements"
" are currently supported");
$$.bits = 32;
}
}
| celllist cellval
| '<'
{
$$ = data_append_cell($1, $2);
$$.data = empty_data;
$$.bits = 32;
}
| celllist DT_REF
| arrayprefix DT_LITERAL
{
$$ = data_append_cell(data_add_marker($1, REF_PHANDLE,
$2), -1);
uint64_t val = eval_literal($2, 0, $1.bits);

$$.data = data_append_integer($1.data, val, $1.bits);
}
| celllist DT_LABEL
| arrayprefix DT_CHAR_LITERAL
{
$$ = data_add_marker($1, LABEL, $2);
}
;
uint64_t val = eval_char_literal($2);

cellval:
DT_LITERAL
$$.data = data_append_integer($1.data, val, $1.bits);
}
| arrayprefix DT_REF
{
$$ = eval_literal($1, 0, 32);
uint64_t val = ~0ULL >> (64 - $1.bits);

if ($1.bits == 32)
$1.data = data_add_marker($1.data,
REF_PHANDLE,
$2);
else
print_error("References are only allowed in "
"arrays with 32-bit elements.");

$$.data = data_append_integer($1.data, val, $1.bits);
}
| DT_CHAR_LITERAL
| arrayprefix DT_LABEL
{
$$ = eval_char_literal($1);
$$.data = data_add_marker($1.data, LABEL, $2);
}
;


1
tests/.gitignore vendored

@ -40,6 +40,7 @@ @@ -40,6 +40,7 @@
/set_name
/setprop
/setprop_inplace
/sized_cells
/string_escapes
/subnode_offset
/supernode_atdepth_offset

1
tests/Makefile.tests

@ -6,6 +6,7 @@ LIB_TESTS_L = get_mem_rsv \ @@ -6,6 +6,7 @@ LIB_TESTS_L = get_mem_rsv \
node_check_compatible node_offset_by_compatible \
get_alias \
char_literal \
sized_cells \
notfound \
setprop_inplace nop_property nop_node \
sw_tree1 \

3
tests/run_tests.sh

@ -209,6 +209,9 @@ dtc_tests () { @@ -209,6 +209,9 @@ dtc_tests () {
run_dtc_test -I dts -O dtb -o dtc_char_literal.test.dtb char_literal.dts
run_test char_literal dtc_char_literal.test.dtb

run_dtc_test -I dts -O dtb -o dtc_sized_cells.test.dtb sized_cells.dts
run_test sized_cells dtc_sized_cells.test.dtb

run_dtc_test -I dts -O dtb -o dtc_extra-terminating-null.test.dtb extra-terminating-null.dts
run_test extra-terminating-null dtc_extra-terminating-null.test.dtb


84
tests/sized_cells.c

@ -0,0 +1,84 @@ @@ -0,0 +1,84 @@
/*
* libfdt - Flat Device Tree manipulation
* Testcase for variable sized cells in dtc
* Copyright (C) 2006 David Gibson, IBM Corporation.
* Copyright (C) 2011 The Chromium Authors. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>

#include <fdt.h>
#include <libfdt.h>

#include "tests.h"
#include "testdata.h"

static void check_compare_properties(void *fdt,
char const *name_one,
char const *name_two)
{
const void *propval;
int proplen;

propval = fdt_getprop(fdt, 0, name_one, &proplen);

if (!propval)
FAIL("fdt_getprop(\"%s\"): %s",
name_one,
fdt_strerror(proplen));

check_getprop(fdt, 0, name_two, proplen, propval);
}

int main(int argc, char *argv[])
{
void *fdt;
uint8_t expected_8[6] = {TEST_CHAR1,
TEST_CHAR2,
TEST_CHAR3,
TEST_CHAR4,
TEST_CHAR5,
TEST_VALUE_1 >> 24};
uint16_t expected_16[6];
uint32_t expected_32[6];
uint64_t expected_64[6];
int i;

for (i = 0; i < 5; ++i) {
expected_16[i] = cpu_to_fdt16(expected_8[i]);
expected_32[i] = cpu_to_fdt32(expected_8[i]);
expected_64[i] = cpu_to_fdt64(expected_8[i]);
}

expected_16[5] = cpu_to_fdt16(TEST_VALUE_1 >> 16);
expected_32[5] = cpu_to_fdt32(TEST_VALUE_1);
expected_64[5] = cpu_to_fdt64(TEST_ADDR_1);

test_init(argc, argv);
fdt = load_blob_arg(argc, argv);

check_getprop(fdt, 0, "cells-8b", sizeof(expected_8), expected_8);
check_getprop(fdt, 0, "cells-16b", sizeof(expected_16), expected_16);
check_getprop(fdt, 0, "cells-32b", sizeof(expected_32), expected_32);
check_getprop(fdt, 0, "cells-64b", sizeof(expected_64), expected_64);

check_compare_properties(fdt, "cells-one-16b", "cells-one-32b");

PASS();
}

11
tests/sized_cells.dts

@ -0,0 +1,11 @@ @@ -0,0 +1,11 @@
/dts-v1/;

/ {
cells-8b = /bits/ 8 <'\r' 'b' '\0' '\'' '\xff' 0xde>;
cells-16b = /bits/ 16 <'\r' 'b' '\0' '\'' '\xff' 0xdead>;
cells-32b = /bits/ 32 <'\r' 'b' '\0' '\'' '\xff' 0xdeadbeef>;
cells-64b = /bits/ 64 <'\r' 'b' '\0' '\'' '\xff' 0xdeadbeef00000000>;

cells-one-16b = /bits/ 16 <0x1234 0x5678 0x0 0xffff>;
cells-one-32b = <0x12345678 0x0000ffff>;
};
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