[prefix] Make unlzma.S compatible with 386 class CPUs

Replace the bswap instruction with xchgb and roll and change the
module architecture from i486 to i386 to be consistent with the rest
of the project.

Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/x86/prefix/unlzma.S b/src/arch/x86/prefix/unlzma.S
index e4d1e190d0350c76a2132c5172901e0630239896..6ab3222e2ad92f90a4423339e0e308215509b8da 100644 (file)
--- a/src/arch/x86/prefix/unlzma.S
+++ b/src/arch/x86/prefix/unlzma.S
@@ -45,7 +45,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
        .section ".note.GNU-stack", "", @progbits
        .code32
-       .arch i486
+       .arch i386
        .section ".prefix.lib", "ax", @progbits
 
 #ifdef CODE16
@@ -962,7 +962,9 @@ decompress:
        ADDR32 lodsb    /* discard initial byte */
        print_hex_byte %al
        ADDR32 lodsl
-       bswapl  %eax
+       xchgb   %al, %ah
+       roll    $16, %eax
+       xchgb   %al, %ah
        print_hex_dword %eax
        print_character $('\n')
        movl    %eax, rc_code(%ebp)