mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-23 10:15:57 +01:00
31 lines
1.1 KiB
ArmAsm
31 lines
1.1 KiB
ArmAsm
#include <lkmc.h>
|
|
|
|
.global lkmc_start
|
|
lkmc_start:
|
|
/* Prepare the stack for main, mandatory for C code. */
|
|
ldr sp, =stack_top
|
|
|
|
/* Enable floating point.
|
|
* Code copied from: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0409h/CHDEGGFF.html
|
|
* Without this, SIMD operations such as vmov raise an exception.
|
|
*/
|
|
mrc p15, 0, r0, c1, c0, 2 /* Read CPACR into r0 */
|
|
orr r0, r0, 3 << 20 /* OR in User and Privileged access for CP10 */
|
|
orr r0, r0, 3 << 22 /* OR in User and Privileged access for CP11 */
|
|
bic r0, r0, 3 << 30 /* Clear ASEDIS/D32DIS if set */
|
|
mcr p15, 0, r0, c1, c0, 2 /* Store new access permissions into CPACR */
|
|
isb /* Ensure side-effect of CPACR is visible */
|
|
mov r0, 1 << 30 /* Create value with FPEXC (bit 30) set in r0 */
|
|
vmsr fpexc, r0 /* Enable VFP and SIMD extensions */
|
|
|
|
/* https://github.com/cirosantilli/linux-kernel-module-cheat#magic-failure-string */
|
|
ldr r0, =lkmc_baremetal_on_exit_callback
|
|
bl on_exit
|
|
|
|
/* Run main. */
|
|
mov r0, 0
|
|
bl main
|
|
|
|
/* If main returns, exit. */
|
|
bl exit
|