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authorPhilipp Hug <philipp@hug.cx>2018-07-07 15:54:37 +0200
committerRonald G. Minnich <rminnich@gmail.com>2018-09-14 14:33:09 +0000
commit2326a284ac6a6646a918331425952ece2da723c1 (patch)
treed83f6fc80597a33132895edd356171547c753343 /util
parent2912e8e5dc66708703db79df87e3215408a653ae (diff)
downloadcoreboot-2326a284ac6a6646a918331425952ece2da723c1.tar.xz
riscv: add trampoline in MBR block to support boot mode 1
Add "j pc + 0x0800" at the beginning of the MBR to jump to bootblock. Tested on hardware: boot mode 15: works as before boot mode 1: jump to bootblock works, but bootblock needs to be modified to move the stack to L2LIM. This will be in a separate commit. Further changes are needed in the bootblock Change-Id: I16e762d9f027346b124412f1f7ee6ff37f431d86 Signed-off-by: Philipp Hug <philipp@hug.cx> Reviewed-on: https://review.coreboot.org/27397 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Diffstat (limited to 'util')
-rwxr-xr-xutil/riscv/sifive-gpt.py14
1 files changed, 13 insertions, 1 deletions
diff --git a/util/riscv/sifive-gpt.py b/util/riscv/sifive-gpt.py
index cb77302528..fd82997fc6 100755
--- a/util/riscv/sifive-gpt.py
+++ b/util/riscv/sifive-gpt.py
@@ -25,6 +25,12 @@ BLOCK_MASK = BLOCK_SIZE - 1
# Size of the bootcode part of the MBR
MBR_BOOTCODE_SIZE = 0x1be
+# MBR trampoline to bootblock
+MBR_BOOTCODE = bytes([
+ # j pc + 0x0800
+ 0x6f, 0x00, 0x10, 0x00,
+])
+
# A protecive MBR, without the bootcode part
PROTECTIVE_MBR_FOOTER = bytes([
0x00, 0x00, 0x02, 0x00, 0xee, 0xff, 0xff, 0xff,
@@ -43,7 +49,7 @@ PROTECTIVE_MBR_FOOTER = bytes([
# [1]: https://en.wikipedia.org/wiki/GUID_Partition_Table#PROTECTIVE-MBR
class ProtectiveMBR:
def __init__(self):
- self.bootcode = bytes(MBR_BOOTCODE_SIZE)
+ self.bootcode = MBR_BOOTCODE + bytes(MBR_BOOTCODE_SIZE - len(MBR_BOOTCODE))
def generate(self, stream):
assert len(self.bootcode) == MBR_BOOTCODE_SIZE
@@ -177,5 +183,11 @@ if __name__ == '__main__':
image.fixup()
+ # Verify if first partition is at expected lba, otherwise trampoline will
+ # fail
+ if image.partitions[0].first_lba != 4:
+ print('Warning: First partition not at expected location (LBA 4)')
+ sys.exit(1)
+
with open(sys.argv[2], 'wb') as f:
image.generate(f)