Hi James,
On 03/12/15 18:54, James Hogan wrote:
On 3 December 2015 17:46:14 GMT+00:00, Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
On 12/03/2015 05:53 PM, Matt Redfearn wrote:
If CONFIG_RELOCATABLE is enabled, jump to relocate_kernel.
This function will return the entry point of the relocated kernel
if
copy/relocate is sucessful or the original entry point if not. The
stack
pointer must then be pointed into the new image.
Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>
---
arch/mips/kernel/head.S | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 4e4cc5b9a771..7dc043349d66 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -132,7 +132,27 @@ not_found:
set_saved_sp sp, t0, t1
PTR_SUBU sp, 4 * SZREG # init stack pointer
+#ifdef CONFIG_RELOCATABLE
+ /* Copy kernel and apply the relocations */
+ jal relocate_kernel
+
+ /* Repoint the sp into the new kernel image */
+ PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE
+ PTR_ADDU sp, $28
Can't you account for it in the previous PTR_LI?
During relocate_kernel, $28, pointer to the current thread,
Ah, it's a register! I thought it was an immediate. Nevermind then. :-)
Although, it could still be reduced:
PTR_ADDU sp, gp, _THREAD_SIZE - 32 - PT_SIZE
Assuming the immediate is in range of signed 16bit.
The immediate would be 32552, so in range of signed 16bit, but that
would be brittle if either _THREAD_SIZE or PT_SIZE were to change in
future....
Thanks,
Matt
Cheers
James
[...]
MBR, Sergei
