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Improve device tree blob (DTB) handling in loader(8).

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Enable using the statically embedded blob from the kernel, if present. The KLD
loaded DTB takes precedence, but they are both recognized and handled in the
same way.

Submitted by:	Lukasz Wojcik
Obtained from:	Semihalf
MFC after:	1 week
This commit is contained in:
Rafal Jaworowski 2012-03-20 13:08:57 +00:00
parent 1e7c7d8cbc
commit 04296b6f18
2 changed files with 113 additions and 25 deletions
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125
sys/boot/fdt/fdt_loader_cmd.c
View File

@ -33,6 +33,9 @@ __FBSDID("$FreeBSD$");
#include <stand.h>
#include <fdt.h>
#include <libfdt.h>
#include <sys/param.h>
#include <sys/linker.h>
#include <machine/elf.h>
#include "bootstrap.h"
#include "glue.h"
@ -56,6 +59,10 @@ __FBSDID("$FreeBSD$");
#define MIN(num1, num2) (((num1) < (num2)) ? (num1):(num2))
#define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
#define FDT_STATIC_DTB_SYMBOL "fdt_static_dtb"
static struct fdt_header *fdtp = NULL;
static int fdt_cmd_nyi(int argc, char *argv[]);
@ -92,6 +99,86 @@ static const struct cmdtab commands[] = {
static char cwd[FDT_CWD_LEN] = "/";
static vm_offset_t
fdt_find_static_dtb(void)
{
Elf_Sym sym;
vm_offset_t dyntab, esym;
uint64_t offs;
struct preloaded_file *kfp;
struct file_metadata *md;
Elf_Sym *symtab;
Elf_Dyn *dyn;
char *strtab, *strp;
int i;
esym = strtab = symtab = 0;
offs = __elfN(relocation_offset);
kfp = file_findfile(NULL, NULL);
if (kfp == NULL)
return (0);
md = file_findmetadata(kfp, MODINFOMD_ESYM);
if (md == NULL)
return (0);
COPYOUT(md->md_data, &esym, sizeof(esym));
md = file_findmetadata(kfp, MODINFOMD_DYNAMIC);
if (md == NULL)
return (0);
COPYOUT(md->md_data, &dyntab, sizeof(dyntab));
dyntab += offs;
/* Locate STRTAB and DYNTAB */
for (dyn = (Elf_Dyn *)dyntab; dyn->d_tag != DT_NULL; dyn++) {
if (dyn->d_tag == DT_STRTAB) {
strtab = (char *)(uintptr_t)(dyn->d_un.d_ptr + offs);
continue;
} else if (dyn->d_tag == DT_SYMTAB) {
symtab = (Elf_Sym *)(uintptr_t)
(dyn->d_un.d_ptr + offs);
continue;
}
}
if (symtab == NULL || strtab == NULL) {
/*
* No symtab? No strtab? That should not happen here,
* and should have been verified during __elfN(loadimage).
* This must be some kind of a bug.
*/
return (0);
}
/*
* The most efficent way to find a symbol would be to calculate a
* hash, find proper bucket and chain, and thus find a symbol.
* However, that would involve code duplication (e.g. for hash
* function). So we're using simpler and a bit slower way: we're
* iterating through symbols, searching for the one which name is
* 'equal' to 'fdt_static_dtb'. To speed up the process a little bit,
* we are eliminating symbols type of which is not STT_NOTYPE, or(and)
* those which binding attribute is not STB_GLOBAL.
*/
for (i = 0; (vm_offset_t)(symtab + i) < esym; i++) {
COPYOUT(symtab + i, &sym, sizeof(sym));
if (ELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
ELF_ST_TYPE(sym.st_info) != STT_NOTYPE)
continue;
strp = strdupout((vm_offset_t)(strtab + sym.st_name));
if (strcmp(strp, FDT_STATIC_DTB_SYMBOL) == 0) {
/* Found a match ! */
free(strp);
return ((vm_offset_t)(sym.st_value + offs));
}
free(strp);
}
return (0);
}
static int
fdt_setup_fdtp()
{
@ -103,10 +190,14 @@ fdt_setup_fdtp()
*/
bfp = file_findfile(NULL, "dtb");
if (bfp == NULL) {
command_errmsg = "no device tree blob loaded";
return (CMD_ERROR);
if ((fdtp = (struct fdt_head *)fdt_find_static_dtb()) == 0) {
command_errmsg = "no device tree blob found!";
return (CMD_ERROR);
}
} else {
/* Dynamic blob has precedence over static. */
fdtp = (struct fdt_header *)bfp->f_addr;
}
fdtp = (struct fdt_header *)bfp->f_addr;
/*
* Validate the blob.
@ -448,7 +539,10 @@ fixup_stdout(const char *env)
}
}
int
/*
* Locate the blob, fix it up and return its location.
*/
void *
fdt_fixup(void)
{
const char *env;
@ -461,13 +555,10 @@ fdt_fixup(void)
ethstr = NULL;
len = 0;
if (!fdtp) {
err = fdt_setup_fdtp();
if (err) {
sprintf(command_errbuf, "Could not perform blob "
"fixups. Error code: %d\n", err);
return (err);
}
err = fdt_setup_fdtp();
if (err) {
sprintf(command_errbuf, "No valid device tree blob found!");
return (NULL);
}
/* Create /chosen node (if not exists) */
@ -477,7 +568,7 @@ fdt_fixup(void)
/* Value assigned to fixup-applied does not matter. */
if (fdt_getprop(fdtp, chosen, "fixup-applied", NULL))
return (CMD_OK);
goto success;
/* Acquire sys_info */
si = ub_get_sys_info();
@ -521,7 +612,8 @@ fdt_fixup(void)
fdt_setprop(fdtp, chosen, "fixup-applied", NULL, 0);
return (CMD_OK);
success:
return (fdtp);
}
int
@ -539,7 +631,8 @@ command_fdt_internal(int argc, char *argv[])
/*
* Check if uboot env vars were parsed already. If not, do it now.
*/
fdt_fixup();
if (fdt_fixup() == NULL)
return (CMD_ERROR);
/*
* Validate fdt <command>.
@ -560,10 +653,6 @@ command_fdt_internal(int argc, char *argv[])
return (CMD_ERROR);
}
if (!fdtp)
if (fdt_setup_fdtp())
return (CMD_ERROR);
/*
* Call command handler.
*/

13
sys/boot/uboot/common/metadata.c
View File

@ -333,13 +333,12 @@ md_load(char *args, vm_offset_t *modulep)
#if defined(LOADER_FDT_SUPPORT)
/* Handle device tree blob */
fdt_fixup();
if ((bfp = file_findfile(NULL, "dtb")) == NULL &&
(howto & RB_VERBOSE))
printf("**WARNING** Booting with no DTB loaded!\n");
dtbp = bfp == NULL ? 0 : bfp->f_addr;
file_addmetadata(kfp, MODINFOMD_DTBP, sizeof dtbp, &dtbp);
dtbp = fdt_fixup();
if (dtbp != (vm_offset_t)NULL)
file_addmetadata(kfp, MODINFOMD_DTBP, sizeof dtbp, &dtbp);
else
pager_output("WARNING! Trying to fire up the kernel, but no "
"device tree blob found!\n");
#endif
file_addmetadata(kfp, MODINFOMD_KERNEND, sizeof kernend, &kernend);