cmd: pxe: add support for FDT overlays
This adds support for specifying FDT overlays in an extlinux/pxelinux
configuration file.
Without this, there is no simple way to apply overlays when the kernel
and fdt is loaded by the pxe command.
This change adds the 'fdtoverlays' keyword for a label, supporting multiple
overlay files to be applied on top of the fdt specified in the 'fdt' or
'devicetree' keyword.
Example:
label linux
kernel /Image
fdt /soc-board.dtb
fdtoverlays /soc-board-function.dtbo
append console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait
This code makes usage of a new variable called fdtoverlay_addr_r used to load
the overlay files without overwritting anything important.
Cc: Tom Rini <trini@konsulko.com>
Cc: Andre Heider <a.heider@gmail.com>
Cc: Jernej Škrabec <jernej.skrabec@siol.net>
Cc: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Jernej Škrabec <jernej.skrabec@siol.net>
Reviewed-by: Jernej Škrabec <jernej.skrabec@siol.net>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/cmd/pxe_utils.c b/cmd/pxe_utils.c
index b9d9a57..3526a65 100644
--- a/cmd/pxe_utils.c
+++ b/cmd/pxe_utils.c
@@ -13,6 +13,8 @@
#include <mapmem.h>
#include <lcd.h>
#include <net.h>
+#include <fdt_support.h>
+#include <linux/libfdt.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <errno.h>
@@ -284,6 +286,9 @@
if (label->fdtdir)
free(label->fdtdir);
+ if (label->fdtoverlays)
+ free(label->fdtoverlays);
+
free(label);
}
@@ -333,6 +338,92 @@
}
/*
+ * Loads fdt overlays specified in 'fdtoverlays'.
+ */
+#ifdef CONFIG_OF_LIBFDT_OVERLAY
+static void label_boot_fdtoverlay(struct cmd_tbl *cmdtp, struct pxe_label *label)
+{
+ char *fdtoverlay = label->fdtoverlays;
+ struct fdt_header *working_fdt;
+ char *fdtoverlay_addr_env;
+ ulong fdtoverlay_addr;
+ ulong fdt_addr;
+ int err;
+
+ /* Get the main fdt and map it */
+ fdt_addr = simple_strtoul(env_get("fdt_addr_r"), NULL, 16);
+ working_fdt = map_sysmem(fdt_addr, 0);
+ err = fdt_check_header(working_fdt);
+ if (err)
+ return;
+
+ /* Get the specific overlay loading address */
+ fdtoverlay_addr_env = env_get("fdtoverlay_addr_r");
+ if (!fdtoverlay_addr_env) {
+ printf("Invalid fdtoverlay_addr_r for loading overlays\n");
+ return;
+ }
+
+ fdtoverlay_addr = simple_strtoul(fdtoverlay_addr_env, NULL, 16);
+
+ /* Cycle over the overlay files and apply them in order */
+ do {
+ struct fdt_header *blob;
+ char *overlayfile;
+ char *end;
+ int len;
+
+ /* Drop leading spaces */
+ while (*fdtoverlay == ' ')
+ ++fdtoverlay;
+
+ /* Copy a single filename if multiple provided */
+ end = strstr(fdtoverlay, " ");
+ if (end) {
+ len = (int)(end - fdtoverlay);
+ overlayfile = malloc(len + 1);
+ strncpy(overlayfile, fdtoverlay, len);
+ overlayfile[len] = '\0';
+ } else
+ overlayfile = fdtoverlay;
+
+ if (!strlen(overlayfile))
+ goto skip_overlay;
+
+ /* Load overlay file */
+ err = get_relfile_envaddr(cmdtp, overlayfile,
+ "fdtoverlay_addr_r");
+ if (err < 0) {
+ printf("Failed loading overlay %s\n", overlayfile);
+ goto skip_overlay;
+ }
+
+ /* Resize main fdt */
+ fdt_shrink_to_minimum(working_fdt, 8192);
+
+ blob = map_sysmem(fdtoverlay_addr, 0);
+ err = fdt_check_header(blob);
+ if (err) {
+ printf("Invalid overlay %s, skipping\n",
+ overlayfile);
+ goto skip_overlay;
+ }
+
+ err = fdt_overlay_apply_verbose(working_fdt, blob);
+ if (err) {
+ printf("Failed to apply overlay %s, skipping\n",
+ overlayfile);
+ goto skip_overlay;
+ }
+
+skip_overlay:
+ if (end)
+ free(overlayfile);
+ } while ((fdtoverlay = strstr(fdtoverlay, " ")));
+}
+#endif
+
+/*
* Boot according to the contents of a pxe_label.
*
* If we can't boot for any reason, we return. A successful boot never
@@ -534,6 +625,11 @@
goto cleanup;
}
}
+
+#ifdef CONFIG_OF_LIBFDT_OVERLAY
+ if (label->fdtoverlays)
+ label_boot_fdtoverlay(cmdtp, label);
+#endif
} else {
bootm_argv[3] = NULL;
}
@@ -591,6 +687,7 @@
T_INCLUDE,
T_FDT,
T_FDTDIR,
+ T_FDTOVERLAYS,
T_ONTIMEOUT,
T_IPAPPEND,
T_BACKGROUND,
@@ -625,6 +722,7 @@
{"fdt", T_FDT},
{"devicetreedir", T_FDTDIR},
{"fdtdir", T_FDTDIR},
+ {"fdtoverlays", T_FDTOVERLAYS},
{"ontimeout", T_ONTIMEOUT,},
{"ipappend", T_IPAPPEND,},
{"background", T_BACKGROUND,},
@@ -1057,6 +1155,11 @@
err = parse_sliteral(c, &label->fdtdir);
break;
+ case T_FDTOVERLAYS:
+ if (!label->fdtoverlays)
+ err = parse_sliteral(c, &label->fdtoverlays);
+ break;
+
case T_LOCALBOOT:
label->localboot = 1;
err = parse_integer(c, &label->localboot_val);