[PATCH 3/3] alpha: support the remaining kernel compression formats
From: Matt Turner <mattst88@gmail.com>
Date: 2026-09-12 19:55:54
Also in:
lkml
Subsystem:
alpha port, the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Linus Torvalds
Nothing about the boot stub is specific to gzip, so wire up bzip2, lz4, lzma, lzo, xz and zstd as well: select the matching HAVE_KERNEL_* symbol, add a suffix-y entry and a compression rule for the piggy-backed image, and include the decompressor into the stub's misc.c. Only gzip's trailer already carries the uncompressed size, so the other formats use the _with_size variants; output_len, which vmlinux.scr takes from the last 4 bytes of the payload, then works for all of them. The stub passes it to __decompress(), which zstd requires. Signed-off-by: Matt Turner <mattst88@gmail.com> --- arch/alpha/Kconfig | 6 ++++++ arch/alpha/boot/compressed/Makefile | 31 +++++++++++++++++++++++++++++-- arch/alpha/boot/compressed/misc.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 2688bb00f175..92cc7bb8d29a 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig@@ -30,7 +30,13 @@ config ALPHA select HAVE_ASM_MODVERSIONS select HAVE_DEBUG_KMEMLEAK select HAVE_GUP_FAST + select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_GZIP + select HAVE_KERNEL_LZ4 + select HAVE_KERNEL_LZMA + select HAVE_KERNEL_LZO + select HAVE_KERNEL_XZ + select HAVE_KERNEL_ZSTD select HAVE_PAGE_SIZE_8KB select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS
diff --git a/arch/alpha/boot/compressed/Makefile b/arch/alpha/boot/compressed/Makefile
index d826f7e4384d..06deaf51fcfa 100644
--- a/arch/alpha/boot/compressed/Makefile
+++ b/arch/alpha/boot/compressed/Makefile@@ -5,7 +5,10 @@ # OBJECTS := head.o misc.o trampoline.o piggy.o -targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz +targets := vmlinux.lds vmlinux vmlinux.bin +targets += vmlinux.bin.bz2 vmlinux.bin.gz vmlinux.bin.lz4 +targets += vmlinux.bin.lzma vmlinux.bin.lzo vmlinux.bin.xz +targets += vmlinux.bin.zst targets += $(OBJECTS) # The stub runs before the kernel has identified the CPU it booted on, so
@@ -18,18 +21,42 @@ KBUILD_CFLAGS += -pipe -mno-fp-regs -ffixed-8 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS KBUILD_CFLAGS += $(CC_FLAGS_DIALECT) +# zstd's decompressor uses __builtin_ctzll()/__builtin_clzll(). Those are +# inline code only with the CIX extension, which the base instruction set +# the stub is built for does not have, so they become calls to libgcc's +# __ctzdi2/__clzdi2. +LIBGCC := $(shell $(CC) -print-libgcc-file-name) + LDFLAGS_vmlinux := -X --orphan-handling=warn -T -$(obj)/vmlinux: $(obj)/vmlinux.lds $(addprefix $(obj)/, $(OBJECTS)) $(LIBS_Y) FORCE +$(obj)/vmlinux: $(obj)/vmlinux.lds $(addprefix $(obj)/, $(OBJECTS)) $(LIBS_Y) $(LIBGCC) FORCE $(call if_changed,ld) OBJCOPYFLAGS_vmlinux.bin := -R .comment -R .note -S $(obj)/vmlinux.bin: vmlinux FORCE $(call if_changed,objcopy) +suffix-$(CONFIG_KERNEL_BZIP2) := bz2 suffix-$(CONFIG_KERNEL_GZIP) := gz +suffix-$(CONFIG_KERNEL_LZ4) := lz4 +suffix-$(CONFIG_KERNEL_LZMA) := lzma +suffix-$(CONFIG_KERNEL_LZO) := lzo +suffix-$(CONFIG_KERNEL_XZ) := xz +suffix-$(CONFIG_KERNEL_ZSTD) := zst +$(obj)/vmlinux.bin.bz2: $(obj)/vmlinux.bin FORCE + $(call if_changed,bzip2_with_size) $(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin FORCE $(call if_changed,gzip) +$(obj)/vmlinux.bin.lz4: $(obj)/vmlinux.bin FORCE + $(call if_changed,lz4_with_size) +$(obj)/vmlinux.bin.lzma: $(obj)/vmlinux.bin FORCE + $(call if_changed,lzma_with_size) +$(obj)/vmlinux.bin.lzo: $(obj)/vmlinux.bin FORCE + $(call if_changed,lzo_with_size) +$(obj)/vmlinux.bin.xz: $(obj)/vmlinux.bin FORCE + $(call if_changed,xzkern_with_size) +$(obj)/vmlinux.bin.zst: $(obj)/vmlinux.bin FORCE + $(call if_changed,zstd22_with_size) LDFLAGS_piggy.o := -r --format binary --oformat elf64-alpha -T $(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.$(suffix-y) FORCE
diff --git a/arch/alpha/boot/compressed/misc.c b/arch/alpha/boot/compressed/misc.c
index 72998582be68..8ffc546e1a15 100644
--- a/arch/alpha/boot/compressed/misc.c
+++ b/arch/alpha/boot/compressed/misc.c@@ -23,6 +23,13 @@ #define STATIC static #define memzero(s, n) memset((s), 0, (n)) +/* + * decompress_unxz.c supplies its own memmove() unless the identifier is + * already a macro. arch/alpha/lib/ has a better one and is already on + * our link line, so take that instead. + */ +#define memmove memmove + extern char input_data[]; extern int input_len; /* output_len is inserted by the linker, possibly at an unaligned address */
@@ -42,10 +49,34 @@ void __noreturn error(char *m) __halt(); } +#ifdef CONFIG_KERNEL_BZIP2 +#include "../../../../lib/decompress_bunzip2.c" +#endif + #ifdef CONFIG_KERNEL_GZIP #include "../../../../lib/decompress_inflate.c" #endif +#ifdef CONFIG_KERNEL_LZ4 +#include "../../../../lib/decompress_unlz4.c" +#endif + +#ifdef CONFIG_KERNEL_LZMA +#include "../../../../lib/decompress_unlzma.c" +#endif + +#ifdef CONFIG_KERNEL_LZO +#include "../../../../lib/decompress_unlzo.c" +#endif + +#ifdef CONFIG_KERNEL_XZ +#include "../../../../lib/decompress_unxz.c" +#endif + +#ifdef CONFIG_KERNEL_ZSTD +#include "../../../../lib/decompress_unzstd.c" +#endif + /* Scratch heap for the decompressors, larger than any of them needs. */ #define STUB_HEAP_SIZE (4 * 1024 * 1024)
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2.54.0