[arm] Split out 32-bit-specific code to arch/arm32

Signed-off-by: Michael Brown <mcb30@ipxe.org>

2 files changed, 134 insertions, 0 deletions

diff --git a/src/arch/arm32/core/arm32_bigint.c b/src/arch/arm32/core/arm32_bigint.c
new file mode 100644
index 000000000..839bead18
--- /dev/null
+++ b/src/arch/arm32/core/arm32_bigint.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2016 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program 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 of the
+ * License, or any later version.
+ *
+ * This program 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; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <string.h>
+#include <ipxe/bigint.h>
+
+/** @file
+ *
+ * Big integer support
+ */
+
+/**
+ * Multiply big integers
+ *
+ * @v multiplicand0	Element 0 of big integer to be multiplied
+ * @v multiplier0	Element 0 of big integer to be multiplied
+ * @v result0		Element 0 of big integer to hold result
+ * @v size		Number of elements
+ */
+void bigint_multiply_raw ( const uint32_t *multiplicand0,
+			   const uint32_t *multiplier0,
+			   uint32_t *result0, unsigned int size ) {
+	const bigint_t ( size ) __attribute__ (( may_alias )) *multiplicand =
+		( ( const void * ) multiplicand0 );
+	const bigint_t ( size ) __attribute__ (( may_alias )) *multiplier =
+		( ( const void * ) multiplier0 );
+	bigint_t ( size * 2 ) __attribute__ (( may_alias )) *result =
+		( ( void * ) result0 );
+	unsigned int i;
+	unsigned int j;
+	uint32_t multiplicand_element;
+	uint32_t multiplier_element;
+	uint32_t *result_elements;
+	uint32_t discard_low;
+	uint32_t discard_high;
+	uint32_t discard_temp;
+
+	/* Zero result */
+	memset ( result, 0, sizeof ( *result ) );
+
+	/* Multiply integers one element at a time */
+	for ( i = 0 ; i < size ; i++ ) {
+		multiplicand_element = multiplicand->element[i];
+		for ( j = 0 ; j < size ; j++ ) {
+			multiplier_element = multiplier->element[j];
+			result_elements = &result->element[ i + j ];
+			/* Perform a single multiply, and add the
+			 * resulting double-element into the result,
+			 * carrying as necessary.  The carry can
+			 * never overflow beyond the end of the
+			 * result, since:
+			 *
+			 *     a < 2^{n}, b < 2^{n} => ab < 2^{2n}
+			 */
+			__asm__ __volatile__ ( "umull %1, %2, %5, %6\n\t"
+					       "ldr %3, [%0]\n\t"
+					       "adds %3, %1\n\t"
+					       "stmia %0!, {%3}\n\t"
+					       "ldr %3, [%0]\n\t"
+					       "adcs %3, %2\n\t"
+					       "stmia %0!, {%3}\n\t"
+					       "bcc 2f\n\t"
+					       "\n1:\n\t"
+					       "ldr %3, [%0]\n\t"
+					       "adcs %3, #0\n\t"
+					       "stmia %0!, {%3}\n\t"
+					       "bcs 1b\n\t"
+					       "\n2:\n\t"
+					       : "+l" ( result_elements ),
+						 "=l" ( discard_low ),
+						 "=l" ( discard_high ),
+						 "=l" ( discard_temp ),
+						 "+m" ( *result )
+					       : "l" ( multiplicand_element ),
+						 "l" ( multiplier_element )
+					       : "cc" );
+		}
+	}
+}
diff --git a/src/arch/arm32/core/setjmp.S b/src/arch/arm32/core/setjmp.S
new file mode 100644
index 000000000..7e7b0fe58
--- /dev/null
+++ b/src/arch/arm32/core/setjmp.S
@@ -0,0 +1,32 @@
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )
+
+	.text
+	.arm
+
+/*
+ * Save stack context for non-local goto
+ */
+	.globl	setjmp
+	.type	setjmp, %function
+setjmp:
+	/* Store registers */
+	stmia	r0, { r4, r5, r6, r7, r8, r9, r10, fp, sp, lr }
+	/* Return 0 when returning as setjmp() */
+	mov	r0, #0
+	bx	lr
+	.size	setjmp, . - setjmp
+
+/*
+ * Non-local jump to a saved stack context
+ */
+	.globl	longjmp
+	.type	longjmp, %function
+longjmp:
+	/* Restore registers */
+	ldmia	r0, { r4, r5, r6, r7, r8, r9, r10, fp, sp, lr }
+	/* Force result to non-zero */
+	movs	r0, r1
+	moveq	r0, #1
+	/* Return to setjmp() caller */
+	bx	lr
+	.size	longjmp, . - longjmp