arm: Put assembly functions into separate sections

This patch changes the ENTRY() macro in asm.h to create a new section
for every assembler function, thus providing dcache_clean/invalidate_all
and friends with the same --gc-sections goodness that our C functions
have. This requires a few minor changes of moving around data (to make
sure it ends up in the right section) and changing some libgcc functions
(which apparently need to have two names?), but nothing serious.

(You may note that some of our assembly functions have data, sometimes
even writable, within the same .text section. This has been this way
before and I'm not looking to change it for now, although it's not
totally clean. Since we don't enforce read-only sections through paging,
it doesn't really hurt.)

BUG=None
TEST=Nyan and Snow still boot. Confirm dcache_invalidate_all is not
output into any binary anymore since no one actually uses it.

Original-Change-Id: I247b29d6173ba516c8dff59126c93b66f7dc4b8d
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/183891
(cherry picked from commit 4a3f2e45e06cc8592d56c3577f41ff879f10e9cc)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ieaa4f2ea9d81c5b9e2b36a772ff9610bdf6446f9
Reviewed-on: http://review.coreboot.org/7451
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>

20 files changed, 59 insertions, 66 deletions

diff --git a/payloads/libpayload/arch/arm/exception_asm.S b/payloads/libpayload/arch/arm/exception_asm.S
index 31d759335f6e..1f369bcc05ea 100644
--- a/payloads/libpayload/arch/arm/exception_asm.S
+++ b/payloads/libpayload/arch/arm/exception_asm.S
@@ -27,13 +27,7 @@
  * SUCH DAMAGE.
  */
 
-	.global exception_stack_end
-exception_stack_end:
-	.word	0
-
-exception_handler:
-	.word 0
-
+	.text
 
 	.align 6
 	.arm
@@ -88,6 +82,7 @@ exception_common:
 	ldmfd	sp!, { pc }^
 
 
+	.align 2
 _undefined_instruction:	.word exception_undefined_instruction
 _software_interrupt:	.word exception_software_interrupt
 _prefetch_abort:	.word exception_prefetch_abort
@@ -96,6 +91,13 @@ _not_used:		.word exception_not_used
 _irq:			.word exception_irq
 _fiq:			.word exception_fiq
 
+	.global exception_stack_end
+exception_stack_end:
+	.word 0
+
+exception_handler:
+	.word 0
+
 	.thumb
 	.global set_vbar
 	.thumb_func
diff --git a/payloads/libpayload/arch/arm/head.S b/payloads/libpayload/arch/arm/head.S
index 0d23c7256f30..54fdb5defd31 100644
--- a/payloads/libpayload/arch/arm/head.S
+++ b/payloads/libpayload/arch/arm/head.S
@@ -29,10 +29,6 @@
 
 #include <arch/asm.h>
 
-1:
-.align 4
-.word	_stack
-
 /*
  * Our entry point
  */
@@ -43,7 +39,7 @@ ENTRY(_entry)
 	/* TODO: Clear BSS */
 
 	/* Setup new stack */
-	ldr sp, 1b
+	ldr sp, 1f
 
 	/* TODO: Save old stack pointer and link register */
 
@@ -57,3 +53,7 @@ ENTRY(_entry)
 	/* Return to the original context. */
 	bx lr
 ENDPROC(_entry)
+
+.align 4
+1:
+.word	_stack
diff --git a/payloads/libpayload/arch/arm/memcpy.S b/payloads/libpayload/arch/arm/memcpy.S
index b8f857bb5678..1388d05ad986 100644
--- a/payloads/libpayload/arch/arm/memcpy.S
+++ b/payloads/libpayload/arch/arm/memcpy.S
@@ -52,8 +52,6 @@
 	ldmfd sp!, {r0, \reg1, \reg2}
 	.endm
 
-	.text
-
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 
 ENTRY(memcpy)
diff --git a/payloads/libpayload/arch/arm/memmove.S b/payloads/libpayload/arch/arm/memmove.S
index dc29f7458cd8..bd5f8f1ac51a 100644
--- a/payloads/libpayload/arch/arm/memmove.S
+++ b/payloads/libpayload/arch/arm/memmove.S
@@ -13,8 +13,6 @@
 #include <arch/asm.h>
 #include "asmlib.h"
 
-		.text
-
 /*
  * Prototype: void *memmove(void *dest, const void *src, size_t n);
  *
diff --git a/payloads/libpayload/arch/arm/memset.S b/payloads/libpayload/arch/arm/memset.S
index 945767c599cb..0c1102deb4c1 100644
--- a/payloads/libpayload/arch/arm/memset.S
+++ b/payloads/libpayload/arch/arm/memset.S
@@ -13,9 +13,6 @@
 #include <arch/asm.h>
 #include "asmlib.h"
 
-	.text
-	.align	5
-
 ENTRY(memset)
 	ands	r3, r0, #3		@ 1 unaligned?
 	mov	ip, r0			@ preserve r0 as return value
diff --git a/payloads/libpayload/include/arm/arch/asm.h b/payloads/libpayload/include/arm/arch/asm.h
index 9e9e7ceff4fe..7bf2aa8974bb 100644
--- a/payloads/libpayload/include/arm/arch/asm.h
+++ b/payloads/libpayload/include/arm/arch/asm.h
@@ -40,16 +40,14 @@
 	END(name)
 
 #define ENTRY(name) \
-	.globl name; \
+	.section .text.name, "ax", %progbits; \
+	.global name; \
 	ALIGN; \
 	name:
 
 #define END(name) \
 	.size name, .-name
 
-/* Everything should go into the text section by default. */
-	.text
-
 /* Thumb code uses the (new) unified assembly syntax. */
 THUMB(	.syntax unified )
 
diff --git a/src/arch/arm/armv4/bootblock.S b/src/arch/arm/armv4/bootblock.S
index 58a34cff7e9b..e4d43029fec5 100644
--- a/src/arch/arm/armv4/bootblock.S
+++ b/src/arch/arm/armv4/bootblock.S
@@ -31,7 +31,6 @@
 
 #include <arch/asm.h>
 
-.section ".start", "a", %progbits
 ENTRY(_start)
 	/*
 	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
diff --git a/src/arch/arm/armv7/bootblock.S b/src/arch/arm/armv7/bootblock.S
index 9ed5d543aacf..a15d1672ca9f 100644
--- a/src/arch/arm/armv7/bootblock.S
+++ b/src/arch/arm/armv7/bootblock.S
@@ -31,7 +31,6 @@
 
 #include <arch/asm.h>
 
-.section ".start", "a", %progbits
 .arm
 ENTRY(_start)
 	/*
diff --git a/src/arch/arm/armv7/exception_asm.S b/src/arch/arm/armv7/exception_asm.S
index dd456363e940..1f369bcc05ea 100644
--- a/src/arch/arm/armv7/exception_asm.S
+++ b/src/arch/arm/armv7/exception_asm.S
@@ -27,13 +27,7 @@
  * SUCH DAMAGE.
  */
 
-	.global exception_stack_end
-exception_stack_end:
-	.word 0
-
-exception_handler:
-	.word 0
-
+	.text
 
 	.align 6
 	.arm
@@ -88,6 +82,7 @@ exception_common:
 	ldmfd	sp!, { pc }^
 
 
+	.align 2
 _undefined_instruction:	.word exception_undefined_instruction
 _software_interrupt:	.word exception_software_interrupt
 _prefetch_abort:	.word exception_prefetch_abort
@@ -96,6 +91,13 @@ _not_used:		.word exception_not_used
 _irq:			.word exception_irq
 _fiq:			.word exception_fiq
 
+	.global exception_stack_end
+exception_stack_end:
+	.word 0
+
+exception_handler:
+	.word 0
+
 	.thumb
 	.global set_vbar
 	.thumb_func
diff --git a/src/arch/arm/bootblock.ld b/src/arch/arm/bootblock.ld
index 2b04b2247511..8d05c7b5a5f6 100644
--- a/src/arch/arm/bootblock.ld
+++ b/src/arch/arm/bootblock.ld
@@ -35,7 +35,7 @@ SECTIONS
 	. = CONFIG_BOOTBLOCK_BASE;
 
 	.bootblock . : {
-		*(.start);
+		*(.text._start);
 		KEEP(*(.id));
 		*(.text);
 		*(.text.*);
@@ -56,4 +56,4 @@ SECTIONS
 		*(.note.*)
 		*(.ARM.*)
 	}
-}
\ No newline at end of file
+}
diff --git a/src/arch/arm/include/arch/asm.h b/src/arch/arm/include/arch/asm.h
index a57ce4dafa98..420fa602a62b 100644
--- a/src/arch/arm/include/arch/asm.h
+++ b/src/arch/arm/include/arch/asm.h
@@ -43,16 +43,14 @@
 	END(name)
 
 #define ENTRY(name) \
-	.globl name; \
+	.section .text.name, "ax", %progbits; \
+	.global name; \
 	ALIGN; \
 	name:
 
 #define END(name) \
 	.size name, .-name
 
-/* Everything should go into the text section by default. */
-	.text
-
 /* Thumb code uses the (new) unified assembly syntax. */
 THUMB(	.syntax unified )
 
diff --git a/src/arch/arm/libgcc/ashldi3.S b/src/arch/arm/libgcc/ashldi3.S
index bf7e7e75c435..3009f18b837e 100644
--- a/src/arch/arm/libgcc/ashldi3.S
+++ b/src/arch/arm/libgcc/ashldi3.S
@@ -39,7 +39,8 @@ Boston, MA 02110-1301, USA.  */
 #endif
 
 ENTRY(__ashldi3)
-ENTRY(__aeabi_llsl)
+.global __aeabi_llsl
+__aeabi_llsl:
 
 	subs	r3, r2, #32
 	rsb	ip, r2, #32
@@ -51,7 +52,8 @@ ENTRY(__aeabi_llsl)
 	mov	al, al, lsl r2
 	mov	pc, lr
 
+.type __aeabi_llsl, %function
+.size __aeabi_llsl, .-__aeabi_llsl
 ENDPROC(__ashldi3)
-ENDPROC(__aeabi_llsl)
 
 #endif
diff --git a/src/arch/arm/libgcc/lib1funcs.S b/src/arch/arm/libgcc/lib1funcs.S
index 533c369d6ed9..f78a937afc2f 100644
--- a/src/arch/arm/libgcc/lib1funcs.S
+++ b/src/arch/arm/libgcc/lib1funcs.S
@@ -206,7 +206,8 @@ Boston, MA 02111-1307, USA.  */
 
 
 ENTRY(__udivsi3)
-ENTRY(__aeabi_uidiv)
+.global __aeabi_uidiv
+__aeabi_uidiv:
 
 	subs	r2, r1, #1
 	moveq	pc, lr
@@ -230,8 +231,9 @@ ENTRY(__aeabi_uidiv)
 	mov	r0, r0, lsr r2
 	mov	pc, lr
 
+.type __aeabi_uidiv, %function
+.size __aeabi_uidiv, .-__aeabi_uidiv
 ENDPROC(__udivsi3)
-ENDPROC(__aeabi_uidiv)
 
 ENTRY(__umodsi3)
 
@@ -250,7 +252,8 @@ ENTRY(__umodsi3)
 ENDPROC(__umodsi3)
 
 ENTRY(__divsi3)
-ENTRY(__aeabi_idiv)
+.global __aeabi_idiv
+__aeabi_idiv:
 
 	cmp	r1, #0
 	eor	ip, r0, r1			@ save the sign of the result.
@@ -287,8 +290,9 @@ ENTRY(__aeabi_idiv)
 	rsbmi	r0, r0, #0
 	mov	pc, lr
 
+.type __aeabi_idiv, %function
+.size __aeabi_idiv, .-__aeabi_idiv
 ENDPROC(__divsi3)
-ENDPROC(__aeabi_idiv)
 
 ENTRY(__modsi3)
 
diff --git a/src/arch/arm/libgcc/lshrdi3.S b/src/arch/arm/libgcc/lshrdi3.S
index 5a5809a17e35..7af0c8312335 100644
--- a/src/arch/arm/libgcc/lshrdi3.S
+++ b/src/arch/arm/libgcc/lshrdi3.S
@@ -39,7 +39,8 @@ Boston, MA 02110-1301, USA.  */
 #endif
 
 ENTRY(__lshrdi3)
-ENTRY(__aeabi_llsr)
+.global __aeabi_llsr
+__aeabi_llsr:
 
 	subs	r3, r2, #32
 	rsb	ip, r2, #32
@@ -51,7 +52,8 @@ ENTRY(__aeabi_llsr)
 	mov	ah, ah, lsr r2
 	mov	pc, lr
 
+.type __aeabi_llsr, %function
+.size __aeabi_llsr, .-__aeabi_llsr
 ENDPROC(__lshrdi3)
-ENDPROC(__aeabi_llsr)
 
 #endif
diff --git a/src/arch/arm/libgcc/muldi3.S b/src/arch/arm/libgcc/muldi3.S
index f6a40a8dc2c9..652dacab26b9 100644
--- a/src/arch/arm/libgcc/muldi3.S
+++ b/src/arch/arm/libgcc/muldi3.S
@@ -27,7 +27,8 @@
 #endif
 
 ENTRY(__muldi3)
-ENTRY(__aeabi_lmul)
+.global __aeabi_lmul
+__aeabi_lmul:
 
 	mul	xh, yl, xh
 	mla	xh, xl, yh, xh
@@ -45,7 +46,8 @@ ENTRY(__aeabi_lmul)
 	adc	xh, xh, ip, lsr #16
 	mov	pc, lr
 
+.type __aeabi_lmul, %function
+.size __aeabi_lmul, .-__aeabi_lmul
 ENDPROC(__muldi3)
-ENDPROC(__aeabi_lmul)
 
 #endif
diff --git a/src/arch/arm/memcpy.S b/src/arch/arm/memcpy.S
index b8f857bb5678..1388d05ad986 100644
--- a/src/arch/arm/memcpy.S
+++ b/src/arch/arm/memcpy.S
@@ -52,8 +52,6 @@
 	ldmfd sp!, {r0, \reg1, \reg2}
 	.endm
 
-	.text
-
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 
 ENTRY(memcpy)
diff --git a/src/arch/arm/memmove.S b/src/arch/arm/memmove.S
index dc29f7458cd8..bd5f8f1ac51a 100644
--- a/src/arch/arm/memmove.S
+++ b/src/arch/arm/memmove.S
@@ -13,8 +13,6 @@
 #include <arch/asm.h>
 #include "asmlib.h"
 
-		.text
-
 /*
  * Prototype: void *memmove(void *dest, const void *src, size_t n);
  *
diff --git a/src/arch/arm/memset.S b/src/arch/arm/memset.S
index 945767c599cb..0c1102deb4c1 100644
--- a/src/arch/arm/memset.S
+++ b/src/arch/arm/memset.S
@@ -13,9 +13,6 @@
 #include <arch/asm.h>
 #include "asmlib.h"
 
-	.text
-	.align	5
-
 ENTRY(memset)
 	ands	r3, r0, #3		@ 1 unaligned?
 	mov	ip, r0			@ preserve r0 as return value
diff --git a/src/soc/nvidia/tegra124/bootblock_asm.S b/src/soc/nvidia/tegra124/bootblock_asm.S
index 58a34cff7e9b..e4d43029fec5 100644
--- a/src/soc/nvidia/tegra124/bootblock_asm.S
+++ b/src/soc/nvidia/tegra124/bootblock_asm.S
@@ -31,7 +31,6 @@
 
 #include <arch/asm.h>
 
-.section ".start", "a", %progbits
 ENTRY(_start)
 	/*
 	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
diff --git a/src/soc/nvidia/tegra124/maincpu.S b/src/soc/nvidia/tegra124/maincpu.S
index 91981ac1ca13..11367480ad63 100644
--- a/src/soc/nvidia/tegra124/maincpu.S
+++ b/src/soc/nvidia/tegra124/maincpu.S
@@ -29,16 +29,6 @@
 
 #include <arch/asm.h>
 
-	.align 2
-
-	.global maincpu_stack_pointer
-maincpu_stack_pointer:
-	.word 0
-
-	.global maincpu_entry_point
-maincpu_entry_point:
-	.word 0
-
 .arm
 ENTRY(maincpu_setup)
 	/*
@@ -54,3 +44,13 @@ ENTRY(maincpu_setup)
 	ldr	r0, maincpu_entry_point
 	bx	r0
 ENDPROC(maincpu_setup)
+
+	.align 2
+
+	.global maincpu_stack_pointer
+maincpu_stack_pointer:
+	.word 0
+
+	.global maincpu_entry_point
+maincpu_entry_point:
+	.word 0