microblaze: Save and restore first unused vector

Use one memory space to detect little/big endian platforms.
The first unused address(0x28) is used instead 0x0 address (reset vectors).
Detection rewrited reset vector setup from first stage bootloader.

Workflow:
1. Store 0x28 to r7
2. Do little/big endian test
3. Restore r7 to 0x28

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2010-11-15 09:54:43 +00:00
parent 86c1b2a86b
commit f3090fce77

View file

@ -51,8 +51,10 @@ _start:
* 4b) BIG endian - r10 contains 0x0 because 0x2 offset is on addr 0x3
*/
addik r6, r0, 0x2 /* BIG/LITTLE endian offset */
swi r6, r0, 0
lbui r10, r0, 0
lwi r7, r0, 0x28
swi r6, r0, 0x28 /* used first unused MB vector */
lbui r10, r0, 0x28 /* used first unused MB vector */
swi r7, r0, 0x28
/* add opcode instruction for 32bit jump - 2 instruction imm & brai */
addi r2, r0, 0xb0000000 /* hex b000 opcode imm */