support variable-size SPI chip for dummy programmer

This is designed for firmware updater to pack firmware image
preserving some specific partitions in any size.

TEST=ran the command line below:
$ flashrom -p dummy:image=${TMP_FILE},size=16777216, \
emulate=VARIABLE_SIZE -w ${IMG} -V -f

$ flashrom -p dummy:image=${TMP_FILE},size=auto, \
emulate=VARIABLE_SIZE -w ${IMG} -V -f

Signed-off-by: Namyoon Woo <>
Change-Id: Iff266e151459561b126ecfd1c47420b385be1db2
Tested-by: build bot (Jenkins) <>
Reviewed-by: Edward O'Callaghan <>
3 files changed