Stefan Haberland 6825645a21 zipl: Move stage 3 loader to external file ...

The first component that gets control after IPL is the zIPL-provided
stage 3 boot loader. This boot loader is based on a binary image linked
into the zIPL executable. When preparing a disk for IPL, zIPL updates
runtime parameters in the boot loader image and writes the resulting
data to disk.

To support the Secure Boot firmware feature, the stage 3 code must be
signed, and can therefore no longer contain variable parameter portions.
Also the boot loader image should be accessible as a separate file to
enable the use of external programs for creating the signature.

This patch moves the stage 3 boot loader code to an external file
location and splits out the parameter portion into a separate, unsigned
on-disk component.

The new memory layout of the stage 3 loader during its execution looks
as follows:

 * 0x0000-0x1fff        Lowcore
 * 0x2000-0x5fff        Memory allocation (heap)
 * 0x7000-0x8fff        free
 * 0x9000-0x9fff        Stage3 parameter
 * 0xa000-0xcfff        Stage3 code
 * 0xd000-0xefff        Section: bss, rodata, data
 * 0xf000-0xffff        Stack

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

2019-04-29 17:17:21 +02:00

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