From: Stephen Warren swarren@nvidia.com
People who write (or scripts that auto-generate) extlinux.conf don't want to know about HW-specific information such as FDT filenames. Create a new extlinux.conf tag "fdtdir" that specifies only the directory where FDT files are located, and defer all knowledge of the filename to U-Boot. The algorithm implemented is:
========== if $fdt_addr_r is set: if "fdt" tag was specified in extlinux.conf: load the FDT from the filename in the tag else if "fdtdir" tag was specified in extlinux.conf: if "fdtfile" is set in the environment: load the FDT from filename in "$fdtfile" else: load the FDT from some automatically generated filename
if no FDT file was loaded, and $fdtaddr is set: # This indicates an FDT packaged with firmware use the FDT at $fdtaddr ==========
A small part of an example /boot/extlinux.conf might be:
========== LABEL primary LINUX zImage FDTDIR ./
LABEL failsafe LINUX bkp/zImage FDTDIR bkp/ ==========
... with /boot/tegra20-seaboard.dtb or /boot/bkp/tegra20-seaboard.dtb being loaded by the sysboot/pxe code.
Signed-off-by: Stephen Warren swarren@nvidia.com --- common/cmd_pxe.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 71 insertions(+), 6 deletions(-)
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c index 20569bb04201..5d356295e48e 100644 --- a/common/cmd_pxe.c +++ b/common/cmd_pxe.c @@ -459,6 +459,7 @@ struct pxe_label { char *append; char *initrd; char *fdt; + char *fdtdir; int ipappend; int attempted; int localboot; @@ -531,6 +532,9 @@ static void label_destroy(struct pxe_label *label) if (label->fdt) free(label->fdt);
+ if (label->fdtdir) + free(label->fdtdir); + free(label); }
@@ -689,13 +693,67 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label) bootm_argv[3] = getenv("fdt_addr_r");
/* if fdt label is defined then get fdt from server */ - if (bootm_argv[3] && label->fdt) { - if (get_relfile_envaddr(cmdtp, label->fdt, "fdt_addr_r") < 0) { - printf("Skipping %s for failure retrieving fdt\n", - label->name); - return 1; + if (bootm_argv[3]) { + char *fdtfile = NULL; + char *fdtfilefree = NULL; + + if (label->fdt) { + fdtfile = label->fdt; + } else if (label->fdtdir) { + fdtfile = getenv("fdtfile"); + /* + * For complex cases, it might be worth calling a + * board- or SoC-provided function here to provide a + * better default: + * + * if (!fdtfile) + * fdtfile = gen_fdtfile(); + * + * If this is added, be sure to keep the default below, + * or move it to the default weak implementation of + * gen_fdtfile(). + */ + if (!fdtfile) { + char *soc = getenv("soc"); + char *board = getenv("board"); + char *slash; + + len = strlen(label->fdtdir); + if (!len) + slash = "./"; + else if (label->fdtdir[len - 1] != '/') + slash = "/"; + else + slash = ""; + + len = strlen(label->fdtdir) + strlen(slash) + + strlen(soc) + 1 + strlen(board) + 5; + fdtfilefree = malloc(len); + if (!fdtfilefree) { + printf("malloc fail (FDT filename)\n"); + return 1; + } + + snprintf(fdtfilefree, len, "%s%s%s-%s.dtb", + label->fdtdir, slash, soc, board); + fdtfile = fdtfilefree; + } } - } else + + if (fdtfile) { + int err = get_relfile_envaddr(cmdtp, fdtfile, "fdt_addr_r"); + free(fdtfilefree); + if (err < 0) { + printf("Skipping %s for failure retrieving fdt\n", + label->name); + return 1; + } + } else { + bootm_argv[3] = NULL; + } + } + + if (!bootm_argv[3]) bootm_argv[3] = getenv("fdt_addr");
if (bootm_argv[3]) @@ -730,6 +788,7 @@ enum token_type { T_PROMPT, T_INCLUDE, T_FDT, + T_FDTDIR, T_ONTIMEOUT, T_IPAPPEND, T_INVALID @@ -760,6 +819,7 @@ static const struct token keywords[] = { {"initrd", T_INITRD}, {"include", T_INCLUDE}, {"fdt", T_FDT}, + {"fdtdir", T_FDTDIR}, {"ontimeout", T_ONTIMEOUT,}, {"ipappend", T_IPAPPEND,}, {NULL, T_INVALID} @@ -1148,6 +1208,11 @@ static int parse_label(char **c, struct pxe_menu *cfg) err = parse_sliteral(c, &label->fdt); break;
+ case T_FDTDIR: + if (!label->fdtdir) + err = parse_sliteral(c, &label->fdtdir); + break; + case T_LOCALBOOT: label->localboot = 1; err = parse_integer(c, &label->localboot_val);