From a28e46b7cc3da7f7b0f8c20e23fe4563bb8fcc52 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Wed, 6 Jun 2018 20:51:05 +0200 Subject: [PATCH] ar71xx: lzma-loader: move padding workaround to gzip step Some devices (TP-Link TL-WR1043ND v1) don't boot reliably when the uncompressed loader is too small. This was workarounded in the loader by adding 512KB of padding to the .data section of the loader binary. This approach had two issues: - The padding was only working when .data was non-empty (otherwise the section would become NOBITS, omitting it in the binary). .data was only empty when no CMDLINE was set, leading to further workarounds like fe594bf90d09 ("ath79: fix loader-okli, lzma-loader"), and this workaround was only effective because a missing "const" led to the kernel argv being stored in .data instead of .rodata - The padding was not only added to the compressed .gz loader, but also uncompressed .bin and .elf loaders. The prevented embedding the kernel cmdline in the loader for non-gz loader types. To fix both issues, move the creation of the padding from the linker script to the gzip step. Signed-off-by: Matthias Schiffer --- target/linux/ar71xx/image/lzma-loader/Makefile | 6 +++++- target/linux/ar71xx/image/lzma-loader/src/loader.lds | 1 - 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/target/linux/ar71xx/image/lzma-loader/Makefile b/target/linux/ar71xx/image/lzma-loader/Makefile index 9b81e87306..738093a958 100644 --- a/target/linux/ar71xx/image/lzma-loader/Makefile +++ b/target/linux/ar71xx/image/lzma-loader/Makefile @@ -47,7 +47,11 @@ loader-compile: $(PKG_BUILD_DIR)/.prepared clean all loader.gz: $(PKG_BUILD_DIR)/loader.bin - gzip -nc9 $< > $(LOADER_GZ) + # Workaround for buggy bootloaders: Some devices + # (TP-Link TL-WR1043ND v1) don't work correctly when + # the uncompressed loader is too small (probably a cache + # invalidation issue) + dd if=$< bs=512K conv=sync | gzip -nc9 > $(LOADER_GZ) loader.elf: $(PKG_BUILD_DIR)/loader.elf $(CP) $< $(LOADER_ELF) diff --git a/target/linux/ar71xx/image/lzma-loader/src/loader.lds b/target/linux/ar71xx/image/lzma-loader/src/loader.lds index 80cc7ca3ec..01ff852361 100644 --- a/target/linux/ar71xx/image/lzma-loader/src/loader.lds +++ b/target/linux/ar71xx/image/lzma-loader/src/loader.lds @@ -13,7 +13,6 @@ SECTIONS { .data : { *(.data) *(.data.*) - . = . + 524288; /* workaround for buggy bootloaders */ } . = ALIGN(32);