switch-coreboot/util/dtc/dtc.h
Ronald G. Minnich 3b79d32caf This is an incredibly long commit message, but I want it in here as I
expect to hear about this change. Note that Stefan and I have discussed
this change and feel it is at least worth trying. 

Also, please be aware that this change is backed by a
lot of experience with LinuxBIOS users and usage of the last 7 years. 

First I detail changes, then I detail why. 


Major changes for the new config system. 
Selection of object files, and variable setting, is now controlled by
Kconfig. 

There is only one dts now. It is in the mainboard file. It may later 
move to the target file -- we will see. 

The dts is in two parts, seperated by %%. The first part is a 
fairly standard dts, and the dtc will automatically generate a device 
tree from it. The device tree is composed of generic structures. These 
structures are identical to those of the old V2 device tree. All the 
hierarchy and parent/child/sibling relationships appear to be correctly
generated. This means that all the v2 code will work without change. 

For each node in the tree, if the node has a  property named 'config', 
then the dtc will generate a reference to a structure and an include
directive for a path -- much as in the old Config tool. 

Example: here is a fragment of a dts
==========
north {
        config = "northbridge,intel,i440bx";
};

%%

struct northbridge_intel_i440bx_config north = {
        .whatever = 1;
};
===========

The dtc will create:
#include <northbridge/intel/i440gx/config.h>
struct northbridge_intel_i440bx_config north = {
        .whatever = 1;
};

struct device dev_north {
        .chip_ops = &northbridge_intel_i440bx_ops;
        .chip_info = &north;

        .
        .
        .
};

So the programmer specifies the tree structure in dts form, indicates
which devices have a config entry, and sets up the C code for the
config. I have worked with this and am finding it very easy to use. I
think this is the way to go. Plus, we are getting rid of most of the 
include hell of the old Config system. 

Note that the config node is OPTTONAL! If you do not set it then no
structure usage/include will occur. 

WHY? 
Here is my setup for v3. I think this is good. I like it and am
finding it easy to work with.

Basically, the old config system combined makefile generation, tree
generation, and chip struct initialization in one file -- config.lb.

What we need are four things:
1. selection of .c files to build the bios with
2. the device tree -- this is built with generic structures defined in
include/device/device.h
3. The per-chip structures, usually defined in, e.g.,
northbridge/intel/i440bx/chip.h
4. setting of variables such as baud rate, etc.

Again, this was all done in Config.lb, spread all over the place, like this:
config chip.h
object superio.o

This was hard for people. So we moved the makefile stuff out into the
Kconfig system. This change eliminates (1) and (4) above.

OK, what's left? Well, with our plans from last October, we had device
object model tree stuff, AND still had chip struct initialization in
one file. (2) and (3) above. This is tough, because I was fighting the
mapping of DTS stuff to the C code. It was getting just as ugly as the
old Config.lb. I have been struggling with this for months and it just
wasn't going anywhere.

But it's way too hard to set up the device tree by hand -- I've tried
it. OTOH, it's really easy to set up the per-chip stuff by hand --
I've tried that too. I did a search via:
find ~/src/LinuxBIOSv2/src/ -name chip.h -print
and looked at them all. These files are really simple. There's no
reason to get too tricky, as there is nothing worth getting tricky
about. The problem is the device tree, not these simple chip info
structs.

So, here's the solution.

The ONLY dts is in the mainboard directory. There is no equivalent of
Config.lb in the south, north, cpu, all that stuff any more. The
Kconfig and Makefile in those directories replaced the build-related
functions of Config.lb.-- (1) and (4) above.  The only thing left was
chip.h anyway (3) above.

But how can we express the settings in chip.h via the DTS? IT's been
very hard to get this going.

So, here is the trick. The dts in the mainboard directory divides into
two parts. The first part is the standard dts. The second part is the
C code. They are seperated, as in lex and yacc, with a %%.

Here is the dts for qemu (note that the cpus keyword is still not
right, and maybe this structure needs to change; i'm not that worried
about that too much, just the big picture I'm discussing here). Also,
note I'm working with some new properties, e.g. pcipath and pcidomain
-- if these properties exist ina node, then I create initialized
structure members for them. Also see enabled and on_mainboard --
properties, but I catch them and use them.
/{
       cpus {
               config="mainboard,emulation,qemu-i386";
               emulation,qemu-i386@0{
                       enabled;
                       on_mainboard;
                       device_type = "cpu";
                       name = "emulation,qemu-i386";
                       pcidomain = "0";

                       /* the I/O stuff */
                       northbridge,intel,440bx{
                               pcipath = "0,0";
                               southbridge,intel,piix4{
                               };
                       };
               };
       };


};

%%
/* the user sets up these structs */
struct mainboard_emulation_qemu_i386_config cpus = {
               .nothing = 1,
};

You can see the device tree stuff at top. If a given node has a
property named 'config', then that means what the old 'chip' thing
meant in Config.lb. The dtc will generate an #include to pull in a
file with the path name specified in the config property. The dtc will
not set up the per-chip struct, but it will set up a pointer to a
struct when it sets up the device tree. Note that at bottom, it's up
to you to set up the initialized struct. But this was always the easy
part anyway. Instead of wacky pseudo-C like we had in config.lb, we
just do real C. It's easy. Here is what the dtc generates.

#include <device/device.h>
#include <device/pci.h>
#include <mainboard/emulation/qemu-i386/config.h>
struct device dev_southbridge_intel_piix4;
struct device dev_northbridge_intel_440bx;
struct device dev_emulation_qemu_i386_0;
struct device dev_cpus;
struct device dev_root;
extern struct chip_operations mainboard_emulation_qemu_i386_ops;
struct mainboard_emulation_qemu_i386_config cpus = {
.nothing = 1,
};

struct device dev_root = {
       .path =  { .type = DEVICE_PATH_ROOT },
       .links = 1,
       .link = {
               [0] = {
                       .dev = &dev_root,
                       .link = 0,
                       .children = &dev_cpus
               },
       },
       .bus = &dev_root.link[0],
};
struct device dev_cpus = {
       .chip_ops = &mainboard_emulation_qemu_i386_ops,
       .chip_info = &cpus,
       .links = 1,
       .link = {
               [0] = {
                       .dev = &dev_cpus,
                       .link = 0,
                       .children = &dev_emulation_qemu_i386_0
               },
       },
       .bus = &dev_root.link[0],
       .next = &dev_root,
};
struct device dev_emulation_qemu_i386_0 = {
       .enabled = 1,
       .on_mainboard = 1,
       .path = {.type=DEVICE_PATH_PCI_DOMAIN,.u={.pci_domain={ .domain = 0 }}}
,
       .links = 1,
       .link = {
               [0] = {
                       .dev = &dev_emulation_qemu_i386_0,
                       .link = 0,
                       .children = &dev_northbridge_intel_440bx
               },
       },
       .bus = &dev_cpus.link[0],
       .next = &dev_cpus,
};
struct device dev_northbridge_intel_440bx = {
       .path = {.type=DEVICE_PATH_PCI,.u={.pci={ .devfn = PCI_DEVFN(0,0)}}},
       .links = 1,
       .link = {
               [0] = {
                       .dev = &dev_northbridge_intel_440bx,
                       .link = 0,
                       .children = &dev_southbridge_intel_piix4
               },
       },
       .bus = &dev_emulation_qemu_i386_0.link[0],
       .next = &dev_emulation_qemu_i386_0,
};
struct device dev_southbridge_intel_piix4 = {
       .bus = &dev_northbridge_intel_440bx.link[0],
       .next = &dev_northbridge_intel_440bx,
};



This compiles just fine.

I think this is the right way to go, comments to me.

But, note, IT COMPILES. And it's simple. And, it will work with our
current device tree code!



Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>


git-svn-id: svn://coreboot.org/repository/LinuxBIOSv3@59 f3766cd6-281f-0410-b1cd-43a5c92072e9
2007-01-26 17:30:40 +00:00

234 lines
5.7 KiB
C

#ifndef _DTC_H
#define _DTC_H
/*
* (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation. 2005.
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <unistd.h>
#include <netinet/in.h>
#include <endian.h>
#include <byteswap.h>
#include "flat_dt.h"
static inline void die(char * str, ...)
{
va_list ap;
va_start(ap, str);
fprintf(stderr, "FATAL ERROR: ");
vfprintf(stderr, str, ap);
exit(1);
}
static inline void *xmalloc(size_t len)
{
void *new = malloc(len);
if (! new)
die("malloc() failed\n");
return new;
}
static inline void *xrealloc(void *p, size_t len)
{
void *new = realloc(p, len);
if (! new)
die("realloc() failed (len=%d)\n", len);
return new;
}
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;
typedef u32 cell_t;
#define cpu_to_be16(x) htons(x)
#define be16_to_cpu(x) ntohs(x)
#define cpu_to_be32(x) htonl(x)
#define be32_to_cpu(x) ntohl(x)
#if __BYTE_ORDER == __BIG_ENDIAN
#define cpu_to_be64(x) (x)
#define be64_to_cpu(x) (x)
#else
#define cpu_to_be64(x) bswap_64(x)
#define be64_to_cpu(x) bswap_64(x)
#endif
#define streq(a, b) (strcmp((a), (b)) == 0)
#define strneq(a, b, n) (strncmp((a), (b), (n)) == 0)
#define ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1))
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
/* Data blobs */
struct fixup {
int offset;
char *ref;
struct fixup *next;
};
struct data {
int len;
unsigned char *val;
int asize;
struct fixup *refs;
};
#define empty_data \
((struct data){.len = 0, .val = NULL, .asize = 0, .refs = NULL})
void fixup_free(struct fixup *f);
void data_free(struct data d);
struct data data_grow_for(struct data d, int xlen);
struct data data_copy_mem(char *mem, int len);
struct data data_copy_escape_string(char *s, int len);
struct data data_copy_file(FILE *f, size_t len);
struct data data_append_data(struct data d, void *p, int len);
struct data data_append_cell(struct data d, cell_t word);
struct data data_append_re(struct data d, struct reserve_entry *re);
struct data data_append_addr(struct data d, u64 addr);
struct data data_append_byte(struct data d, uint8_t byte);
struct data data_append_zeroes(struct data d, int len);
struct data data_append_align(struct data d, int align);
struct data data_add_fixup(struct data d, char *ref);
int data_is_one_string(struct data d);
/* DT constraints */
#define MAX_PROPNAME_LEN 31
#define MAX_NODENAME_LEN 31
/* Live trees */
struct property {
char *name;
struct data val;
struct property *next;
char *label;
};
struct node {
char *name;
struct property *proplist;
struct node *children;
struct node *parent;
struct node *next_sibling;
struct node *next;
char *fullpath;
int basenamelen;
cell_t phandle;
int addr_cells, size_cells;
char *label;
};
#define for_each_property(n, p) \
for ((p) = (n)->proplist; (p); (p) = (p)->next)
#define for_each_child(n, c) \
for ((c) = (n)->children; (c); (c) = (c)->next_sibling)
struct property *build_property(char *name, struct data val, char *label);
struct property *chain_property(struct property *first, struct property *list);
struct node *build_node(struct property *proplist, struct node *children);
struct node *name_node(struct node *node, char *name, char *label);
struct node *chain_node(struct node *first, struct node *list);
void add_property(struct node *node, struct property *prop);
void add_child(struct node *parent, struct node *child);
int check_device_tree(struct node *dt, int outversion, int boot_cpuid_phys);
/* Boot info (tree plus memreserve information */
struct reserve_info {
struct reserve_entry re;
struct reserve_info *next;
char *label;
};
struct reserve_info *build_reserve_entry(u64 start, u64 len, char *label);
struct reserve_info *chain_reserve_entry(struct reserve_info *first,
struct reserve_info *list);
struct reserve_info *add_reserve_entry(struct reserve_info *list,
struct reserve_info *new);
struct boot_info {
struct reserve_info *reservelist;
struct node *dt; /* the device tree */
};
struct boot_info *build_boot_info(struct reserve_info *reservelist,
struct node *tree);
/* Flattened trees */
void dt_to_blob(FILE *f, struct boot_info *bi, int version,
int boot_cpuid_phys);
void dt_to_asm(FILE *f, struct boot_info *bi, int version,
int boot_cpuid_phys);
void dt_to_C(FILE *f, struct boot_info *bi, int version, int boot_cpuid_phys);
void dt_to_linuxbios(FILE *f, struct boot_info *bi, int version, int boot_cpuid_phys);
struct boot_info *dt_from_blob(FILE *f);
/* Tree source */
void dt_to_source(FILE *f, struct boot_info *bi);
struct boot_info *dt_from_source(FILE *f);
/* FS trees */
struct boot_info *dt_from_fs(char *dirname);
/* misc */
char *join_path(char *path, char *name);
void fill_fullpaths(struct node *tree, char *prefix);
#endif /* _DTC_H */