#include <asm/page.h>
#include <asm/virt.h>
-#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
+#define __PHYS_OFFSET (KERNEL_START - TEXT_OFFSET)
#if (TEXT_OFFSET & 0xfff) != 0
#error TEXT_OFFSET must be at least 4KB aligned
#error TEXT_OFFSET must be less than 2MB
#endif
- .macro pgtbl, ttb0, ttb1, virt_to_phys
- ldr \ttb1, =swapper_pg_dir
- ldr \ttb0, =idmap_pg_dir
- add \ttb1, \ttb1, \virt_to_phys
- add \ttb0, \ttb0, \virt_to_phys
- .endm
-
#ifdef CONFIG_ARM64_64K_PAGES
#define BLOCK_SHIFT PAGE_SHIFT
#define BLOCK_SIZE PAGE_SIZE
#define TABLE_SHIFT PUD_SHIFT
#endif
-#define KERNEL_START KERNEL_RAM_VADDR
+#define KERNEL_START _text
#define KERNEL_END _end
/*
#endif
ENTRY(stext)
- mov x21, x0 // x21=FDT
+ bl preserve_boot_args
bl el2_setup // Drop to EL1, w20=cpu_boot_mode
- bl __calc_phys_offset // x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
+ adrp x24, __PHYS_OFFSET
bl set_cpu_boot_mode_flag
- mrs x22, midr_el1 // x22=cpuid
- mov x0, x22
- bl lookup_processor_type
- mov x23, x0 // x23=current cpu_table
- /*
- * __error_p may end up out of range for cbz if text areas are
- * aligned up to section sizes.
- */
- cbnz x23, 1f // invalid processor (x23=0)?
- b __error_p
-1:
+
bl __vet_fdt
bl __create_page_tables // x25=TTBR0, x26=TTBR1
/*
- * The following calls CPU specific code in a position independent
- * manner. See arch/arm64/mm/proc.S for details. x23 = base of
- * cpu_info structure selected by lookup_processor_type above.
+ * The following calls CPU setup code, see arch/arm64/mm/proc.S for
+ * details.
* 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
- ldr x12, [x23, #CPU_INFO_SETUP]
- add x12, x12, x28 // __virt_to_phys
- br x12 // initialise processor
+ adr_l lr, __enable_mmu // return (PIC) address
+ b __cpu_setup // initialise processor
ENDPROC(stext)
+/*
+ * Preserve the arguments passed by the bootloader in x0 .. x3
+ */
+preserve_boot_args:
+ mov x21, x0 // x21=FDT
+
+ adr_l x0, boot_args // record the contents of
+ stp x21, x1, [x0] // x0 .. x3 at kernel entry
+ stp x2, x3, [x0, #16]
+
+ dmb sy // needed before dc ivac with
+ // MMU off
+
+ add x1, x0, #0x20 // 4 x 8 bytes
+ b __inval_cache_range // tail call
+ENDPROC(preserve_boot_args)
+
/*
* Determine validity of the x21 FDT pointer.
* The dtb must be 8-byte aligned and live in the first 512M of memory.
* - pgd entry for fixed mappings (TTBR1)
*/
__create_page_tables:
- pgtbl x25, x26, x28 // idmap_pg_dir and swapper_pg_dir addresses
+ adrp x25, idmap_pg_dir
+ adrp x26, swapper_pg_dir
mov x27, lr
/*
* Create the identity mapping.
*/
mov x0, x25 // idmap_pg_dir
- ldr x3, =KERNEL_START
- add x3, x3, x28 // __pa(KERNEL_START)
+ adrp x3, KERNEL_START // __pa(KERNEL_START)
create_pgd_entry x0, x3, x5, x6
- ldr x6, =KERNEL_END
mov x5, x3 // __pa(KERNEL_START)
- add x6, x6, x28 // __pa(KERNEL_END)
+ adr_l x6, KERNEL_END // __pa(KERNEL_END)
create_block_map x0, x7, x3, x5, x6
/*
mov x0, x26 // swapper_pg_dir
mov x5, #PAGE_OFFSET
create_pgd_entry x0, x5, x3, x6
- ldr x6, =KERNEL_END
+ ldr x6, =KERNEL_END // __va(KERNEL_END)
mov x3, x24 // phys offset
create_block_map x0, x7, x3, x5, x6
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 processor_id // x4
- .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
+ adr_l x6, __bss_start
+ adr_l x7, __bss_stop
- ldp x6, x7, [x3], #16
1: cmp x6, x7
b.hs 2f
str xzr, [x6], #8 // Clear BSS
b 1b
2:
- ldp x4, x5, [x3], #16
- ldr x6, [x3], #8
- ldr x16, [x3]
- mov sp, x16
- str x22, [x4] // Save processor ID
- str x21, [x5] // Save FDT pointer
- str x24, [x6] // Save PHYS_OFFSET
+ adr_l sp, initial_sp, x4
+ str_l x21, __fdt_pointer, x5 // Save FDT pointer
+ str_l x24, memstart_addr, x6 // Save PHYS_OFFSET
mov x29, #0
b start_kernel
ENDPROC(__mmap_switched)
* in x20. See arch/arm64/include/asm/virt.h for more info.
*/
ENTRY(set_cpu_boot_mode_flag)
- ldr x1, =__boot_cpu_mode // Compute __boot_cpu_mode
- add x1, x1, x28
+ adr_l x1, __boot_cpu_mode
cmp w20, #BOOT_CPU_MODE_EL2
b.ne 1f
add x1, x1, #4
* zeroing of .bss would clobber it.
*/
.pushsection .data..cacheline_aligned
-ENTRY(__boot_cpu_mode)
.align L1_CACHE_SHIFT
+ENTRY(__boot_cpu_mode)
.long BOOT_CPU_MODE_EL2
- .long 0
+ .long BOOT_CPU_MODE_EL1
.popsection
#ifdef CONFIG_SMP
- .align 3
-1: .quad .
- .quad secondary_holding_pen_release
-
/*
* This provides a "holding pen" for platforms to hold all secondary
* cores are held until we're ready for them to initialise.
*/
ENTRY(secondary_holding_pen)
bl el2_setup // Drop to EL1, w20=cpu_boot_mode
- bl __calc_phys_offset // x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
bl set_cpu_boot_mode_flag
mrs x0, mpidr_el1
ldr x1, =MPIDR_HWID_BITMASK
and x0, x0, x1
- adr x1, 1b
- ldp x2, x3, [x1]
- sub x1, x1, x2
- add x3, x3, x1
+ adr_l x3, secondary_holding_pen_release
pen: ldr x4, [x3]
cmp x4, x0
b.eq secondary_startup
*/
ENTRY(secondary_entry)
bl el2_setup // Drop to EL1
- bl __calc_phys_offset // x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
bl set_cpu_boot_mode_flag
b secondary_startup
ENDPROC(secondary_entry)
/*
* Common entry point for secondary CPUs.
*/
- mrs x22, midr_el1 // x22=cpuid
- mov x0, x22
- bl lookup_processor_type
- mov x23, x0 // x23=current cpu_table
- cbz x23, __error_p // invalid processor (x23=0)?
-
- pgtbl x25, x26, x28 // x25=TTBR0, x26=TTBR1
- ldr x12, [x23, #CPU_INFO_SETUP]
- add x12, x12, x28 // __virt_to_phys
- blr x12 // initialise processor
+ adrp x25, idmap_pg_dir
+ adrp x26, swapper_pg_dir
+ bl __cpu_setup // initialise processor
ldr x21, =secondary_data
ldr x27, =__secondary_switched // address to jump to after enabling the MMU
#endif /* CONFIG_SMP */
/*
- * Setup common bits before finally enabling the MMU. Essentially this is just
- * loading the page table pointer and vector base registers.
+ * Enable the MMU.
*
- * On entry to this code, x0 must contain the SCTLR_EL1 value for turning on
- * the MMU.
+ * x0 = SCTLR_EL1 value for turning on the MMU.
+ * x27 = *virtual* address to jump to upon completion
+ *
+ * other registers depend on the function called upon completion
*/
__enable_mmu:
ldr x5, =vectors
msr ttbr0_el1, x25 // load TTBR0
msr ttbr1_el1, x26 // load TTBR1
isb
- b __turn_mmu_on
-ENDPROC(__enable_mmu)
-
-/*
- * Enable the MMU. This completely changes the structure of the visible memory
- * space. You will not be able to trace execution through this.
- *
- * x0 = system control register
- * x27 = *virtual* address to jump to upon completion
- *
- * other registers depend on the function called upon completion
- *
- * We align the entire function to the smallest power of two larger than it to
- * ensure it fits within a single block map entry. Otherwise were PHYS_OFFSET
- * close to the end of a 512MB or 1GB block we might require an additional
- * table to map the entire function.
- */
- .align 4
-__turn_mmu_on:
msr sctlr_el1, x0
isb
br x27
-ENDPROC(__turn_mmu_on)
-
-/*
- * Calculate the start of physical memory.
- */
-__calc_phys_offset:
- adr x0, 1f
- ldp x1, x2, [x0]
- sub x28, x0, x1 // x28 = PHYS_OFFSET - PAGE_OFFSET
- add x24, x2, x28 // x24 = PHYS_OFFSET
- ret
-ENDPROC(__calc_phys_offset)
-
- .align 3
-1: .quad .
- .quad PAGE_OFFSET
-
-/*
- * Exception handling. Something went wrong and we can't proceed. We ought to
- * tell the user, but since we don't have any guarantee that we're even
- * running on the right architecture, we do virtually nothing.
- */
-__error_p:
-ENDPROC(__error_p)
-
-__error:
-1: nop
- b 1b
-ENDPROC(__error)
-
-/*
- * This function gets the processor ID in w0 and searches the cpu_table[] for
- * a match. It returns a pointer to the struct cpu_info it found. The
- * cpu_table[] must end with an empty (all zeros) structure.
- *
- * This routine can be called via C code and it needs to work with the MMU
- * both disabled and enabled (the offset is calculated automatically).
- */
-ENTRY(lookup_processor_type)
- adr x1, __lookup_processor_type_data
- ldp x2, x3, [x1]
- sub x1, x1, x2 // get offset between VA and PA
- add x3, x3, x1 // convert VA to PA
-1:
- ldp w5, w6, [x3] // load cpu_id_val and cpu_id_mask
- cbz w5, 2f // end of list?
- and w6, w6, w0
- cmp w5, w6
- b.eq 3f
- add x3, x3, #CPU_INFO_SZ
- b 1b
-2:
- mov x3, #0 // unknown processor
-3:
- mov x0, x3
- ret
-ENDPROC(lookup_processor_type)
-
- .align 3
- .type __lookup_processor_type_data, %object
-__lookup_processor_type_data:
- .quad .
- .quad cpu_table
- .size __lookup_processor_type_data, . - __lookup_processor_type_data
+ENDPROC(__enable_mmu)
projects / cascardo / linux.git / blobdiff