arm: Thumb ALL the things!

This patch switches every last part of Coreboot on ARM over to Thumb
mode: libpayload, the internal libgcc, and assorted assembly files. In
combination with the respective depthcharge patch, this will switch to
Thumb mode right after the entry point of the bootblock and not switch
back to ARM until the final assembly stub that jumps to the kernel.

The required changes to make this work include some new headers and
Makefile flags to handle assembly files (using the unified syntax and
the same helper macros as Linux), modifying our custom-written libgcc
code for 64-bit division to support Thumb (removing some stale old files
that were never really used for clarity), and flipping the general
CFLAGS to Thumb (some more cleanup there as well while I'm at it).

BUG=None
TEST=Snow and Nyan still boot.

Original-Change-Id: I80c04281e3adbf74f9f477486a96b9fafeb455b3
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/182212
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 5f65c17cbfae165a95354146ae79e06c512c2c5a)

Conflicts:
	payloads/libpayload/include/arm/arch/asm.h
	src/arch/arm/Makefile.inc
	src/arch/arm/armv7/Makefile.inc

*** There is an issue with what to do with ramstage-S-ccopts, and
*** will need to be covered in additional ARM cleanup patches.

Change-Id: I80c04281e3adbf74f9f477486a96b9fafeb455b3
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: http://review.coreboot.org/6930
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 0 insertions, 214 deletions

diff --git a/src/arch/arm/libgcc/bpabi.c b/src/arch/arm/libgcc/bpabi.c
deleted file mode 100644
index 8cb7ddf129..0000000000
--- a/src/arch/arm/libgcc/bpabi.c
+++ /dev/null
@@ -1,214 +0,0 @@
-/* Miscellaneous BPABI functions.
-
-   Copyright (C) 2003, 2004  Free Software Foundation, Inc.
-   Contributed by CodeSourcery, LLC.
-
-   This file is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published by the
-   Free Software Foundation; either version 2, or (at your option) any
-   later version.
-
-   In addition to the permissions in the GNU General Public License, the
-   Free Software Foundation gives you unlimited permission to link the
-   compiled version of this file into combinations with other programs,
-   and to distribute those combinations without any restriction coming
-   from the use of this file.  (The General Public License restrictions
-   do apply in other respects; for example, they cover modification of
-   the file, and distribution when not linked into a combine
-   executable.)
-
-   This file is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; see the file COPYING.  If not, write to
-   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
-
-#if defined __GNUC__
-
-#include <stdint.h>
-
-uint64_t __udivmoddi4(uint64_t n, uint64_t d, uint64_t *rp);
-extern int64_t __divdi3(int64_t, int64_t);
-extern uint64_t __udivdi3(uint64_t, uint64_t);
-extern int64_t __gnu_ldivmod_helper(int64_t, int64_t, int64_t *);
-extern uint64_t __gnu_uldivmod_helper(uint64_t, uint64_t, uint64_t *);
-
-typedef union
-{
-	struct {
-		int32_t low;
-		int32_t high;
-	} s;
-	int64_t ll;
-} DWunion;
-
-uint64_t
-__udivmoddi4(uint64_t n, uint64_t d, uint64_t *rp)
-{
-	const DWunion nn = {.ll = n};
-	const DWunion dd = {.ll = d};
-	DWunion rr;
-	uint32_t d0, d1, n0, n1, n2;
-	uint32_t q0, q1;
-	uint32_t b, bm;
-
-	d0 = dd.s.low;
-	d1 = dd.s.high;
-	n0 = nn.s.low;
-	n1 = nn.s.high;
-
-	if (d1 == 0) {
-		if (d0 > n1) {
-			/* 0q = nn / 0D */
-			udiv_qrnnd(q0, n0, n1, n0, d0);
-			q1 = 0;
-			/* Remainder in n0. */
-		} else {
-			/* qq = NN / 0d */
-			if (d0 == 0)
-				d0 = 1 / d0; /* Divide intentionally by zero. */
-
-			udiv_qrnnd(q1, n1, 0, n1, d0);
-			udiv_qrnnd(q0, n0, n1, n0, d0);
-
-			/* Remainder in n0. */
-		}
-
-		if (rp != 0) {
-			rr.s.low = n0;
-			rr.s.high = 0;
-			*rp = rr.ll;
-		}
-	} else {
-		if (d1 > n1) {
-			/* 00 = nn / DD */
-			q0 = 0;
-			q1 = 0;
-
-			/* Remainder in n1n0. */
-			if (rp != 0) {
-				rr.s.low = n0;
-				rr.s.high = n1;
-				*rp = rr.ll;
-			}
-		} else {
-			/* 0q = NN / dd */
-
-			count_leading_zeros(bm, d1);
-			if (bm == 0) {
-				/* From (n1 >= d1) /\ (the most significant
-				   bit of d1 is set), conclude (the most
-				   significant bit of n1 is set) /\ (the
-				   quotient digit q0 = 0 or 1).
-
-				   This special case is necessary, not an
-				   optimization. */
-
-				/* The condition on the next line takes
-				   advantage of that n1 >= d1 (true due to
-				   program flow). */
-				if (n1 > d1 || n0 >= d0) {
-					q0 = 1;
-					sub_ddmmss(n1, n0, n1, n0, d1, d0);
-				} else
-					q0 = 0;
-
-				q1 = 0;
-
-				if (rp != 0) {
-					rr.s.low = n0;
-					rr.s.high = n1;
-					*rp = rr.ll;
-				}
-			} else {
-				uint32_t m1, m0;
-				/* Normalize.  */
-
-				b = 32 - bm;
-
-				d1 = (d1 << bm) | (d0 >> b);
-				d0 = d0 << bm;
-				n2 = n1 >> b;
-				n1 = (n1 << bm) | (n0 >> b);
-				n0 = n0 << bm;
-
-				udiv_qrnnd(q0, n1, n2, n1, d1);
-				umul_ppmm(m1, m0, q0, d0);
-
-				if (m1 > n1 || (m1 == n1 && m0 > n0)) {
-					q0--;
-					sub_ddmmss(m1, m0, m1, m0, d1, d0);
-				}
-
-				q1 = 0;
-
-				/* Remainder in (n1n0 - m1m0) >> bm. */
-				if (rp != 0) {
-					sub_ddmmss(n1, n0, n1, n0, m1, m0);
-					rr.s.low = (n1 << b) | (n0 >> bm);
-					rr.s.high = n1 >> bm;
-					*rp = rr.ll;
-				}
-			}
-		}
-	}
-
-	const DWunion ww = {{.low = q0, .high = q1}};
-	return ww.ll;
-}
-
-int64_t
-__divdi3(int64_t u, int64_t v)
-{
-	int32_t c = 0;
-	DWunion uu = {.ll = u};
-	DWunion vv = {.ll = v};
-	int64_t w;
-
-	if (uu.s.high < 0) {
-		c = ~c;
-		uu.ll = -uu.ll;
-	}
-	if (vv.s.high < 0) {
-		c = ~c;
-		vv.ll = -vv.ll;
-	}
-
-	w = __udivmoddi4(uu.ll, vv.ll, (uint64_t *)0);
-	if (c)
-		w = -w;
-
-	return w;
-}
-
-int64_t
-__gnu_ldivmod_helper (int64_t a, int64_t b, int64_t *remainder)
-{
-	int64_t quotient;
-
-	quotient = __divdi3(a, b);
-	*remainder = a - b * quotient;
-	return quotient;
-}
-
-uint64_t
-__udivdi3(uint64_t n, uint64_t d)
-{
-	return __udivmoddi4(n, d, (uint64_t *)0);
-}
-
-uint64_t
-__gnu_uldivmod_helper(uint64_t a, uint64_t b, uint64_t *remainder)
-{
-	uint64_t quotient;
-
-	quotient = __udivdi3(a, b);
-	*remainder = a - b * quotient;
-	return quotient;
-}
-
-#endif