@@ -263,7 +263,7 @@ ENTRY(stext)
* On return, the CPU will be ready for the MMU to be turned on and
* the TCR will have been set.
*/
- ldr x27, __switch_data // address to jump to after
+ ldr x27, =__mmap_switched // address to jump to after
// MMU has been enabled
adrp lr, __enable_mmu // return (PIC) address
add lr, lr, #:lo12:__enable_mmu
@@ -432,35 +432,27 @@ __create_page_tables:
ENDPROC(__create_page_tables)
.ltorg
- .align 3
- .type __switch_data, %object
-__switch_data:
- .quad __mmap_switched
- .quad __bss_start // x6
- .quad __bss_stop // x7
- .quad __fdt_pointer // x5
- .quad memstart_addr // x6
- .quad init_thread_union + THREAD_START_SP // sp
-
/*
- * The following fragment of code is executed with the MMU on in MMU mode, and
- * uses absolute addresses; this is not position independent.
+ * The following fragment of code is executed with the MMU enabled.
*/
+ .set initial_sp, init_thread_union + THREAD_START_SP
__mmap_switched:
- adr x3, __switch_data + 8
+ adrp x6, __bss_start
+ adrp x7, __bss_stop
+ add x6, x6, :lo12:__bss_start
+ add x7, x7, :lo12:__bss_stop
- ldp x6, x7, [x3], #16
1: cmp x6, x7
b.hs 2f
str xzr, [x6], #8 // Clear BSS
b 1b
2:
- ldr x5, [x3], #8
- ldr x6, [x3], #8
- ldr x16, [x3]
- mov sp, x16
- str x21, [x5] // Save FDT pointer
- str x24, [x6] // Save PHYS_OFFSET
+ adrp x4, initial_sp
+ adrp x5, __fdt_pointer
+ adrp x6, memstart_addr
+ add sp, x4, :lo12:initial_sp
+ str x21, [x5, :lo12:__fdt_pointer] // Save FDT pointer
+ str x24, [x6, :lo12:memstart_addr] // Save PHYS_OFFSET
mov x29, #0
b start_kernel
ENDPROC(__mmap_switched)
This removes the confusing __switch_data object from head.S, and replaces it with standard PC-relative references to the various symbols it encapsulates. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/kernel/head.S | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-)