|author||Stephen Warren <email@example.com>||2015-03-10 15:40:58 -0600|
|committer||Tom Rini <firstname.lastname@example.org>||2015-03-13 09:29:36 -0400|
config_distro_bootcmd.h: add note on error handling
This should make it more clear why there appear to be C pre-processor symbols in the file that contain mixed case. They're really error messages. Suggested-by: Simon Glass <email@example.com> Signed-off-by: Stephen Warren <firstname.lastname@example.org> Reviewed-by: Tom Rini <email@example.com> Reviewed-by: Simon Glass <firstname.lastname@example.org>
1 files changed, 16 insertions, 0 deletions
diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
index 07a0b3b234..73f093f9ea 100644
@@ -10,6 +10,22 @@
+ * A note on error handling: It is possible for BOOT_TARGET_DEVICES to
+ * reference a device that is not enabled in the U-Boot configuration, e.g.
+ * it may include MMC in the list without CONFIG_CMD_MMC being enabled. Given
+ * that BOOT_TARGET_DEVICES is a macro that's expanded by the C pre-processor
+ * at compile time, it's not possible to detect and report such problems via
+ * a simple #ifdef/#error combination. Still, the code needs to report errors.
+ * The best way I've found to do this is to make BOOT_TARGET_DEVICES expand to
+ * reference a non-existent symbol, and have the name of that symbol encode
+ * the error message. Consequently, this file contains references to e.g.
+ * BOOT_TARGET_DEVICES_references_MMC_without_CONFIG_CMD_MMC. Given the
+ * prevalence of capitals here, this looks like a pre-processor macro and
+ * hence seems like it should be all capitals, but it's really an error
+ * message that includes some other pre-processor symbols in the text.
/* We need the part command */