On Tue, Jun 01, 2010 at 10:06:41PM +0800, Wu Zhangjin wrote:
> Changes:
>
> v2 -> v3: (feedback from Alexander Clouter)
> o Drop the unneeded variable n
> o Replace the last "unsigned long long" by uint64_t
>
> v1 -> v2: (feedback from Alexander Clouter)
> o make it more portable
> use EXIT_SUCCESS and EXIT_FAILURE as the return value, and use uint64_t
> instead of "unsigned long long".
> o add a missing return value
> return EXIT_FAILURE if sscanf not return 1.
>
> We have calculated VMLINUZ_LOAD_ADDRESS in shell, which is indecipherable. This
> patch rewrites it in C.
I prefer the C version too as it allow better abstraction
and easier to understand calculations.
> diff --git a/arch/mips/boot/.gitignore b/arch/mips/boot/.gitignore
> index 4667a5f..f210b09 100644
> --- a/arch/mips/boot/.gitignore
> +++ b/arch/mips/boot/.gitignore
> @@ -3,3 +3,4 @@ elf2ecoff
> vmlinux.*
> zImage
> zImage.tmp
> +calc_vmlinuz_load_addr
Does this do any good in this file?
I had assumed this covered only the same dir as the .gitignore file
is stored. But I may be wrong.
> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
> index 7204dfc..cd9ee04 100644
> --- a/arch/mips/boot/compressed/Makefile
> +++ b/arch/mips/boot/compressed/Makefile
>
> -LDFLAGS_vmlinuz := $(LDFLAGS) -Ttext $(VMLINUZ_LOAD_ADDRESS) -T
> -vmlinuz: $(src)/ld.script $(vmlinuzobjs-y) $(obj)/piggy.o
> - $(call cmd,ld)
> +# Calculate the load address of the compressed kernel
> +hostprogs-y := calc_vmlinuz_load_addr
> +
> +vmlinuzobjs-y += $(obj)/piggy.o
> +
> +quiet_cmd_zld = LD $@
> + cmd_zld = $(LD) $(LDFLAGS) -Ttext $(shell $(obj)/calc_vmlinuz_load_addr $(objtree)/$(KBUILD_IMAGE) $(VMLINUX_LOAD_ADDRESS)) -T $< $(vmlinuzobjs-y) -o $@
The line seriously fail the 80 char limit.
Something like this:
load_addr = $(shell $(obj)/calc_vmlinuz_load_addr \
$(objtree)/$(KBUILD_IMAGE) $(VMLINUX_LOAD_ADDRESS)
quiet_cmd_zld = LD $@
cmd_zld = $(LD) $(LDFLAGS) -Ttext $(load-addr) -T $< $(vmlinuzobjs-y) -o $@
Note: The load_addr local variable _must_ use "=" asignment
> +vmlinuz: $(src)/ld.script $(vmlinuzobjs-y) $(obj)/calc_vmlinuz_load_addr
> + $(call cmd,zld)
> $(Q)$(OBJCOPY) $(OBJCOPYFLAGS) $@
Does objcopy support equally named input and out files?
If this is the case you could use:
$(call cmd,objcopy) as the last line.
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <errno.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +int main(int argc, char *argv[])
> +{
> + struct stat sb;
> + uint64_t vmlinux_size, vmlinux_load_addr, vmlinuz_load_addr;
> +
> + if (argc != 3) {
> + fprintf(stderr, "Usage: %s <pathname> <vmlinux_load_addr>\n",
> + argv[0]);
> + return EXIT_FAILURE;
> + }
> +
> + if (stat(argv[1], &sb) == -1) {
> + perror("stat");
> + return EXIT_FAILURE;
> + }
> +
> + /* Convert hex characters to dec number */
> + errno = 0;
> + if (sscanf(argv[2], "%llx", &vmlinux_load_addr) != 1) {
> + if (errno != 0)
> + perror("sscanf");
> + else
> + fprintf(stderr, "No matching characters\n");
> +
> + return EXIT_FAILURE;
> + }
> +
> + vmlinux_size = (uint64_t)sb.st_size;
> + vmlinuz_load_addr = vmlinux_load_addr + vmlinux_size;
> +
> + /* Align with 65536 */
> + vmlinuz_load_addr += (65536 - vmlinux_size % 65536);
You have plenty of rooms for a comment about why you do this.
Would be good to use this possibility.
Sam
