diff options
Diffstat (limited to 'arch/x86/boot/header.S')
| -rw-r--r-- | arch/x86/boot/header.S | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index fd85b9e4e953..3dd5be33aaa7 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -508,13 +508,10 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr # To avoid problems with the compressed data's meta information an extra 18 # bytes are needed. Leading to the formula: # -# extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size +# extra_bytes = (uncompressed_size >> 12) + 32768 + 18 # # Adding 8 bytes per 32K is a bit excessive but much easier to calculate. # Adding 32768 instead of 32767 just makes for round numbers. -# Adding the decompressor_size is necessary as it musht live after all -# of the data as well. Last I measured the decompressor is about 14K. -# 10K of actual data and 4K of bss. # # Above analysis is for decompressing gzip compressed kernel only. Up to # now 6 different decompressor are supported all together. And among them @@ -524,17 +521,35 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr # the description in lib/decompressor_xxx.c for specific information. # # extra_bytes = (uncompressed_size >> 12) + 65536 + 128 -# -# Note that this calculation, which results in z_extract_offset (below), -# is currently generated in compressed/mkpiggy.c -#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_extract_offset) +#define ZO_z_extra_bytes ((ZO_z_output_len >> 12) + 65536 + 128) +#if ZO_z_output_len > ZO_z_input_len +# define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \ + ZO_z_input_len) +#else +# define ZO_z_extract_offset ZO_z_extra_bytes +#endif + +/* + * The extract_offset has to be bigger than ZO head section. Otherwise when + * the head code is running to move ZO to the end of the buffer, it will + * overwrite the head code itself. + */ +#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset +# define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095) +#else +# define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095) +#endif + +#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset) + #define VO_INIT_SIZE (VO__end - VO__text) #if ZO_INIT_SIZE > VO_INIT_SIZE -#define INIT_SIZE ZO_INIT_SIZE +# define INIT_SIZE ZO_INIT_SIZE #else -#define INIT_SIZE VO_INIT_SIZE +# define INIT_SIZE VO_INIT_SIZE #endif + init_size: .long INIT_SIZE # kernel initialization size handover_offset: .long 0 # Filled in by build.c |