diff options
Diffstat (limited to 'arch/arm/cpu/setupc.S')
| -rw-r--r-- | arch/arm/cpu/setupc.S | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm/cpu/setupc.S b/arch/arm/cpu/setupc.S new file mode 100644 index 0000000000..9a8d54c224 --- /dev/null +++ b/arch/arm/cpu/setupc.S @@ -0,0 +1,34 @@ +#include <linux/linkage.h> + +.section .text.setupc + +/* + * setup_c: copy binary to link address, clear bss and + * continue executing at new address. + * + * This function does not return to the address it is + * called from, but to the same location in the copied + * binary. + */ +ENTRY(setup_c) + push {r4, r5} + mov r5, lr + bl get_runtime_offset + subs r4, r0, #0 + beq 1f /* skip memcpy if already at correct address */ + ldr r0,=_text + ldr r2,=__bss_start + sub r2, r2, r0 + sub r1, r0, r4 + bl memcpy /* memcpy(_text, _text - offset, __bss_start - _text) */ +1: ldr r0, =__bss_start + mov r1, #0 + ldr r2, =__bss_stop + sub r2, r2, r0 + bl memset /* clear bss */ + mov r0, #0 + mcr p15, 0, r0, c7, c5, 0 /* flush icache */ + add lr, r5, r4 /* adjust return address to new location */ + pop {r4, r5} + mov pc, lr +ENDPROC(setup_c) |