Re: [PATCH 3/3] alpha: support the remaining kernel compression formats

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_KERNELI built the complete series in separate output directories for all

+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)


--

2.54.0