Re: git: dc6c193bb4a6 - main - loader.efi: Add xz decompression

On 11/07/26 16:30, Warner Losh wrote:
> The branch main has been updated by imp:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=dc6c193bb4a67e2e9ee97d1e3ac3e2950bd16979
> 
> commit dc6c193bb4a67e2e9ee97d1e3ac3e2950bd16979
> Author:     Warner Losh <imp@FreeBSD.org>
> AuthorDate: 2026-07-11 14:44:40 +0000
> Commit:     Warner Losh <imp@FreeBSD.org>
> CommitDate: 2026-07-11 19:28:47 +0000
> 
>      loader.efi: Add xz decompression
>      
>      We can now decompress .xz compressed memory disks, like
>      FreeBSD-15.1-RELEASE-amd64-disc1.iso.xz
>      
>      Sponsored by:           Netflix
>      Differential Revision:  https://reviews.freebsd.org/D58073
> ---
>   stand/defs.mk                               |   5 ++
>   stand/efi/loader/Makefile                   |   2 +-
>   stand/efi/loader/decompress.c               | 101 ++++++++++++++++++++++++++--
>   stand/efi/loader/decompress.h               |   2 +-
>   stand/libsa/Makefile                        |   7 ++
>   sys/contrib/xz-embedded/freebsd/xz_config.h |  11 +--
>   6 files changed, 117 insertions(+), 11 deletions(-)
> 
> diff --git a/stand/defs.mk b/stand/defs.mk
> index 05108404c538..e3908678b53a 100644
> --- a/stand/defs.mk
> +++ b/stand/defs.mk
> @@ -190,6 +190,11 @@ BZIP2_CFLAGS=-I${SRCTOP}/contrib/bzip2  -DBZ_NO_STDIO -DBZ_NO_COMPRESS
>   # ZSTD client cflags
>   ZSTD_CFLAGS=-I${SYSDIR}/contrib/zstd/lib
>   
> +# XZ flags
> +XZ_DIR=${SRCTOP}/sys/contrib/xz-embedded
> +XZ_CFLAGS=-DXZ_USE_CRC64 -I${XZ_DIR}/freebsd -I${XZ_DIR}/linux/include/linux
> +
> +
>   # The boot loader build uses dd status=none, where possible, for reproducible
>   # build output (since performance varies from run to run). Trouble is that
>   # option was recently (10.3) added to FreeBSD and is non-standard. Only use it
> diff --git a/stand/efi/loader/Makefile b/stand/efi/loader/Makefile
> index 164b16ff2a59..b29f0b8f8259 100644
> --- a/stand/efi/loader/Makefile
> +++ b/stand/efi/loader/Makefile
> @@ -47,7 +47,7 @@ HAVE_ZFS=	yes
>   
>   CFLAGS.bootinfo.c += -I$(SRCTOP)/sys/teken
>   CFLAGS.bootinfo.c += -I${SRCTOP}/contrib/pnglite
> -CFLAGS.decompress.c += ${ZLIB_CFLAGS} ${BZIP2_CFLAGS} ${ZSTD_CFLAGS}
> +CFLAGS.decompress.c += ${ZLIB_CFLAGS} ${BZIP2_CFLAGS} ${ZSTD_CFLAGS} ${XZ_CFLAGS}
>   CFLAGS.framebuffer.c += -I$(SRCTOP)/sys/teken
>   CFLAGS.framebuffer.c += -I${SRCTOP}/contrib/pnglite
>   CFLAGS.main.c += -I$(SRCTOP)/sys/teken
> diff --git a/stand/efi/loader/decompress.c b/stand/efi/loader/decompress.c
> index 5c16f7d9bb2a..fb3c6314e4b6 100644
> --- a/stand/efi/loader/decompress.c
> +++ b/stand/efi/loader/decompress.c
> @@ -11,7 +11,8 @@
>   
>   #include <zlib.h>
>   #include <bzlib.h>
> -#ifdef LOADER_ZFS_SUPPORT	/* ZSTD only available with ZFS */
> +#include <xz.h>
> +#ifdef LOADER_ZFS_SUPPORT	/* ZSTD and lzma only available with ZFS */
>   #include <zstd.h>
>   #endif
>   #include <sys/_param.h>
> @@ -32,6 +33,7 @@ struct decomp_state
>   	union {
>   		z_stream zstrm;
>   		bz_stream bzstrm;
> +		struct xz_dec *xzstrm;
>   #ifdef LOADER_ZFS_SUPPORT
>   		ZSTD_DStream *zstdstrm;
>   #endif
> @@ -63,10 +65,10 @@ what_compressed(uint8_t *buf, size_t len)
>   		return (zstd);
>   	}
>   	if (memcmp(buf, "\xfd""7zXZ\x00", 6) == 0) {
> -		printf("xz -- unsupproted\n");
> -	} else {
> -		printf("Not compressed\n");
> +		printf("xz\n");
> +		return (xz);
>   	}
> +	printf("Not compressed\n");
>   	return (none);
>   }
>   
> @@ -220,7 +222,7 @@ bzip2_step(decomp_state *dctx, uint8_t *buf, size_t len, size_t offset)
>   
>           if (ret == BZ_STREAM_END)
>                   return (done);
> -        if (ret != Z_OK)
> +        if (ret != BZ_OK)
>                   return (err);
>           if (dctx->buf_cur < dctx->buf_end) /* Have output space */
>   		return (ok);
> @@ -247,6 +249,90 @@ bzip2_fini(decomp_state *dctx, bool flush)
>   	free_buffer(dctx);
>   }
>   
> +/*
> + * XZ support
> + */
> +static EFI_STATUS
> +xz_init(decomp_state *dctx, uint8_t *first_buf, size_t buflen, size_t size_hint)
> +{
> +	/*
> +	 * Assume 4x compression, but start at 64MB
> +	 */
> +	dctx->size = max(size_hint * 4, M(64));
> +	EFI_STATUS status = alloc_buffer(dctx, dctx->size);
> +	if (EFI_ERROR(status))
> +		return (status);
> +	xz_crc32_init();
> +	xz_crc64_init();
> +	dctx->xzstrm = xz_dec_init(XZ_DYNALLOC, (uint32_t)-1);
> +        return (dctx->xzstrm != NULL ? EFI_SUCCESS : EFI_VOLUME_CORRUPTED);	
> +}
> +
> +
> +static enum step_return
> +xz_step(decomp_state *dctx, uint8_t *buf, size_t len, size_t offset)
> +{
> +	struct xz_dec *strm = dctx->xzstrm;
> +	size_t outlen = dctx->buf_end - dctx->buf_cur;
> +	struct xz_buf b = { .in = buf, .in_size = len, .in_pos = 0,
> +		.out = dctx->buf_cur, .out_size = outlen, .out_pos = 0 };
> +	int ret;
> +	
> +        ret = xz_dec_run(strm, &b);
> +	dctx->buf_cur += b.out_pos;
> +
> +        if (ret == XZ_STREAM_END)
> +                return (done);
> +        if (ret != XZ_OK) {
> +		switch(ret) {
> +		case XZ_MEM_ERROR:
> +			printf("xz no memory ");
> +			break;
> +		case XZ_DATA_ERROR:
> +			printf("xz file corrupted ");
> +			break;
> +		case XZ_FORMAT_ERROR:
> +			printf("xz format not found ");
> +			break;
> +		case XZ_OPTIONS_ERROR:
> +			printf("unsupported xz option ");
> +			break;
> +		case XZ_MEMLIMIT_ERROR:
> +			printf("xz dictionary too small ");
> +			break;
> +		default:
> +			printf("xz step error %d ", ret);
> +			break;
> +		}
> +		printf(" len %d offset %d\n", (int)len, (int)offset);
> +                return (err);
> +	}

Above block seems to be wrongly indented

-- 
Renato Botelho