[PATCH v3 4/4] kexec, x86_64: Load bzImage64 above 4G

[Yinghai Lu]

On Wed, Nov 21, 2012 at 6:50 AM, Vivek Goyal <vgoyal at redhat.com> wrote:
> On Tue, Nov 20, 2012 at 11:31:38PM -0800, Yinghai Lu wrote:
>
> [..]
>> +int bzImage64_probe(const char *buf, off_t len)
>> +{
>> +     const struct x86_linux_header *header;
>> +     if ((uintmax_t)len < (uintmax_t)(2 * 512)) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "File is too short to be a bzImage!\n");
>> +             }
>> +             return -1;
>> +     }
>> +     header = (const struct x86_linux_header *)buf;
>> +     if (memcmp(header->header_magic, "HdrS", 4) != 0) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "Not a bzImage\n");
>> +             }
>> +             return -1;
>> +     }
>> +     if (header->boot_sector_magic != 0xAA55) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "No x86 boot sector present\n");
>> +             }
>> +             /* No x86 boot sector present */
>> +             return -1;
>> +     }
>> +     if (header->protocol_version < 0x020C) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "Must be at least protocol version 2.12\n");
>> +             }
>> +             /* Must be at least protocol version 2.12 */
>> +             return -1;
>> +     }
>> +     if ((header->loadflags & 1) == 0) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "zImage not a bzImage\n");
>> +             }
>> +             /* Not a bzImage */
>> +             return -1;
>> +     }
>> +     if (!(header->xloadflags & 1)) {
>> +             if (probe_debug) {
>> +                     fprintf(stderr, "Not a bzImage64\n");
>> +             }
>> +             /* Must be LOADED_ABOVE_4G */
>> +             return -1;
>> +     }
>
> So how do I force a 16bit or 32bit entry using a bzImage64?

kexec -t bzImage -l ....
will load low and use 32bit entry.

kexec -t bzImage64 -l ...
kexec -l ...
will try to load high and use 64bit entry.