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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2019-04-01 19:10:45 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2019-04-10 17:47:09 +0200
commitbf9921a9c15bad089c08b94c300a6cafa035a612 (patch)
treedd69b006096cdae6c93cb892d892b00dc7e63e68 /arch/s390/boot
parent46a984ffb86c8542fa510656fa8cb33befe8ee8f (diff)
downloadlinux-bf9921a9c15bad089c08b94c300a6cafa035a612.tar.bz2
s390: introduce .boot.preserved.data section
Introduce .boot.preserve.data section which is similar to .boot.data and "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. Unlike .boot.data section .boot.preserved.data is NOT a part of init data, and hence will be preserved for the kernel life time. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/boot')
-rw-r--r--arch/s390/boot/compressed/decompressor.h2
-rw-r--r--arch/s390/boot/compressed/vmlinux.lds.S1
-rw-r--r--arch/s390/boot/startup.c4
3 files changed, 7 insertions, 0 deletions
diff --git a/arch/s390/boot/compressed/decompressor.h b/arch/s390/boot/compressed/decompressor.h
index e1c1f2ec60f4..424cf524aac1 100644
--- a/arch/s390/boot/compressed/decompressor.h
+++ b/arch/s390/boot/compressed/decompressor.h
@@ -17,6 +17,8 @@ struct vmlinux_info {
unsigned long bss_size; /* uncompressed image .bss size */
unsigned long bootdata_off;
unsigned long bootdata_size;
+ unsigned long bootdata_preserved_off;
+ unsigned long bootdata_preserved_size;
};
extern char _vmlinux_info[];
diff --git a/arch/s390/boot/compressed/vmlinux.lds.S b/arch/s390/boot/compressed/vmlinux.lds.S
index 7efc3938f595..1c8ef393c656 100644
--- a/arch/s390/boot/compressed/vmlinux.lds.S
+++ b/arch/s390/boot/compressed/vmlinux.lds.S
@@ -34,6 +34,7 @@ SECTIONS
_edata = . ;
}
BOOT_DATA
+ BOOT_DATA_PRESERVED
/*
* uncompressed image info used by the decompressor it should match
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index bdfc5549a299..57d7f9446e29 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -6,6 +6,7 @@
#include "boot.h"
extern char __boot_data_start[], __boot_data_end[];
+extern char __boot_data_preserved_start[], __boot_data_preserved_end[];
void error(char *x)
{
@@ -43,6 +44,9 @@ static void copy_bootdata(void)
if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
error(".boot.data section size mismatch");
memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
+ if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size)
+ error(".boot.preserved.data section size mismatch");
+ memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size);
}
void startup_kernel(void)