diff --git a/Makefile b/Makefile index c44b023..a252a8b 100644 --- a/Makefile +++ b/Makefile @@ -6,7 +6,7 @@ CFLAGS = -march=armv5te -mfloat-abi=soft -Wall \ AFLAGS = LDFLAGS = --nostdlib -T fernvale.ld -LIBS = +LIBS = lib/libgcc-armv5.a SRC_C = \ bionic.c \ @@ -38,9 +38,6 @@ SRC_S = \ scriptic/spi.S \ scriptic/spi-blockmode.S \ scriptic/keypad.S \ - _lshrdi3.S \ - _udivsi3.S \ - _divsi3.S \ start.S OBJ = $(addprefix $(BUILD)/, $(SRC_S:.S=.o) $(SRC_C:.c=.o)) diff --git a/README.md b/README.md index 39d0956..a37e3d3 100644 --- a/README.md +++ b/README.md @@ -92,6 +92,23 @@ That is, send the following packet: | 00 00 | +Licensing +--------- + +Fernly is licensed under the BSD 2-clause license (see LICENSE). + +Previous versions of fernly linked against division libraries taken from U-Boot, +which were licensed under GPL-2. These files have been removed. + +Instead, we supply a version of libgcc.a. This file was extracted from a +standard gcc toolchain, specifically: + + https://code.google.com/p/yus-repo/downloads/detail?name=arm-none-eabi-4.6-armv5.tar.gz + +It has not been modified, and its distribution here should be covered under +the "runtime exception". + + Memory Map ---------- diff --git a/_divsi3.S b/_divsi3.S deleted file mode 100644 index cfbadb2..0000000 --- a/_divsi3.S +++ /dev/null @@ -1,142 +0,0 @@ - -.macro ARM_DIV_BODY dividend, divisor, result, curbit - -#if __LINUX_ARM_ARCH__ >= 5 - - clz \curbit, \divisor - clz \result, \dividend - sub \result, \curbit, \result - mov \curbit, #1 - mov \divisor, \divisor, lsl \result - mov \curbit, \curbit, lsl \result - mov \result, #0 - -#else - - @ Initially shift the divisor left 3 bits if possible, - @ set curbit accordingly. This allows for curbit to be located - @ at the left end of each 4 bit nibbles in the division loop - @ to save one loop in most cases. - tst \divisor, #0xe0000000 - moveq \divisor, \divisor, lsl #3 - moveq \curbit, #8 - movne \curbit, #1 - - @ Unless the divisor is very big, shift it up in multiples of - @ four bits, since this is the amount of unwinding in the main - @ division loop. Continue shifting until the divisor is - @ larger than the dividend. -1: cmp \divisor, #0x10000000 - cmplo \divisor, \dividend - movlo \divisor, \divisor, lsl #4 - movlo \curbit, \curbit, lsl #4 - blo 1b - - @ For very big divisors, we must shift it a bit at a time, or - @ we will be in danger of overflowing. -1: cmp \divisor, #0x80000000 - cmplo \divisor, \dividend - movlo \divisor, \divisor, lsl #1 - movlo \curbit, \curbit, lsl #1 - blo 1b - - mov \result, #0 - -#endif - - @ Division loop -1: cmp \dividend, \divisor - subhs \dividend, \dividend, \divisor - orrhs \result, \result, \curbit - cmp \dividend, \divisor, lsr #1 - subhs \dividend, \dividend, \divisor, lsr #1 - orrhs \result, \result, \curbit, lsr #1 - cmp \dividend, \divisor, lsr #2 - subhs \dividend, \dividend, \divisor, lsr #2 - orrhs \result, \result, \curbit, lsr #2 - cmp \dividend, \divisor, lsr #3 - subhs \dividend, \dividend, \divisor, lsr #3 - orrhs \result, \result, \curbit, lsr #3 - cmp \dividend, #0 @ Early termination? - movnes \curbit, \curbit, lsr #4 @ No, any more bits to do? - movne \divisor, \divisor, lsr #4 - bne 1b - -.endm - -.macro ARM_DIV2_ORDER divisor, order - -#if __LINUX_ARM_ARCH__ >= 5 - - clz \order, \divisor - rsb \order, \order, #31 - -#else - - cmp \divisor, #(1 << 16) - movhs \divisor, \divisor, lsr #16 - movhs \order, #16 - movlo \order, #0 - - cmp \divisor, #(1 << 8) - movhs \divisor, \divisor, lsr #8 - addhs \order, \order, #8 - - cmp \divisor, #(1 << 4) - movhs \divisor, \divisor, lsr #4 - addhs \order, \order, #4 - - cmp \divisor, #(1 << 2) - addhi \order, \order, #3 - addls \order, \order, \divisor, lsr #1 - -#endif - -.endm - - .align 5 -.globl __divsi3 -.globl __aeabi_idiv -__divsi3: -__aeabi_idiv: - cmp r1, #0 - eor ip, r0, r1 @ save the sign of the result. - beq Ldiv0 - rsbmi r1, r1, #0 @ loops below use unsigned. - subs r2, r1, #1 @ division by 1 or -1 ? - beq 10f - movs r3, r0 - rsbmi r3, r0, #0 @ positive dividend value - cmp r3, r1 - bls 11f - tst r1, r2 @ divisor is power of 2 ? - beq 12f - - ARM_DIV_BODY r3, r1, r0, r2 - - cmp ip, #0 - rsbmi r0, r0, #0 - mov pc, lr - -10: teq ip, r0 @ same sign ? - rsbmi r0, r0, #0 - mov pc, lr - -11: movlo r0, #0 - moveq r0, ip, asr #31 - orreq r0, r0, #1 - mov pc, lr - -12: ARM_DIV2_ORDER r1, r2 - - cmp ip, #0 - mov r0, r3, lsr r2 - rsbmi r0, r0, #0 - mov pc, lr - -Ldiv0: - - str lr, [sp, #-4]! - bl __div0 - mov r0, #0 @ About as wrong as it could be. - ldr pc, [sp], #4 diff --git a/_lshrdi3.S b/_lshrdi3.S deleted file mode 100644 index 33296a0..0000000 --- a/_lshrdi3.S +++ /dev/null @@ -1,26 +0,0 @@ -/* Copyright 1995, 1996, 1998, 1999, 2000, 2003, 2004, 2005 - Free Software Foundation, Inc. - - * SPDX-License-Identifier: GPL-2.0+ - */ - -#ifdef __ARMEB__ -#define al r1 -#define ah r0 -#else -#define al r0 -#define ah r1 -#endif - -.globl __lshrdi3 -.globl __aeabi_llsr -__lshrdi3: -__aeabi_llsr: - - subs r3, r2, #32 - rsb ip, r2, #32 - movmi al, al, lsr r2 - movpl al, ah, lsr r3 - orrmi al, al, ah, lsl ip - mov ah, ah, lsr r2 - mov pc, lr diff --git a/_udivsi3.S b/_udivsi3.S deleted file mode 100644 index 1309802..0000000 --- a/_udivsi3.S +++ /dev/null @@ -1,93 +0,0 @@ -/* # 1 "libgcc1.S" */ -@ libgcc1 routines for ARM cpu. -@ Division routines, written by Richard Earnshaw, (rearnsha@armltd.co.uk) -dividend .req r0 -divisor .req r1 -result .req r2 -curbit .req r3 -/* ip .req r12 */ -/* sp .req r13 */ -/* lr .req r14 */ -/* pc .req r15 */ - .text - .globl __udivsi3 - .type __udivsi3 ,function - .globl __aeabi_uidiv - .type __aeabi_uidiv ,function - .align 0 - __udivsi3: - __aeabi_uidiv: - cmp divisor, #0 - beq Ldiv0 - mov curbit, #1 - mov result, #0 - cmp dividend, divisor - bcc Lgot_result -Loop1: - @ Unless the divisor is very big, shift it up in multiples of - @ four bits, since this is the amount of unwinding in the main - @ division loop. Continue shifting until the divisor is - @ larger than the dividend. - cmp divisor, #0x10000000 - cmpcc divisor, dividend - movcc divisor, divisor, lsl #4 - movcc curbit, curbit, lsl #4 - bcc Loop1 -Lbignum: - @ For very big divisors, we must shift it a bit at a time, or - @ we will be in danger of overflowing. - cmp divisor, #0x80000000 - cmpcc divisor, dividend - movcc divisor, divisor, lsl #1 - movcc curbit, curbit, lsl #1 - bcc Lbignum -Loop3: - @ Test for possible subtractions, and note which bits - @ are done in the result. On the final pass, this may subtract - @ too much from the dividend, but the result will be ok, since the - @ "bit" will have been shifted out at the bottom. - cmp dividend, divisor - subcs dividend, dividend, divisor - orrcs result, result, curbit - cmp dividend, divisor, lsr #1 - subcs dividend, dividend, divisor, lsr #1 - orrcs result, result, curbit, lsr #1 - cmp dividend, divisor, lsr #2 - subcs dividend, dividend, divisor, lsr #2 - orrcs result, result, curbit, lsr #2 - cmp dividend, divisor, lsr #3 - subcs dividend, dividend, divisor, lsr #3 - orrcs result, result, curbit, lsr #3 - cmp dividend, #0 @ Early termination? - movnes curbit, curbit, lsr #4 @ No, any more bits to do? - movne divisor, divisor, lsr #4 - bne Loop3 -Lgot_result: - mov r0, result - mov pc, lr -Ldiv0: - str lr, [sp, #-4]! - bl __div0 (PLT) - mov r0, #0 @ about as wrong as it could be - ldmia sp!, {pc} - .size __udivsi3 , . - __udivsi3 - -.globl __aeabi_uidivmod -__aeabi_uidivmod: - - stmfd sp!, {r0, r1, ip, lr} - bl __aeabi_uidiv - ldmfd sp!, {r1, r2, ip, lr} - mul r3, r0, r2 - sub r1, r1, r3 - mov pc, lr - -.globl __aeabi_idivmod -__aeabi_idivmod: - - stmfd sp!, {r0, r1, ip, lr} - bl __aeabi_idiv - ldmfd sp!, {r1, r2, ip, lr} - mul r3, r0, r2 - sub r1, r1, r3 - mov pc, lr diff --git a/lib/libgcc-armv5.a b/lib/libgcc-armv5.a new file mode 100644 index 0000000..2d4461b Binary files /dev/null and b/lib/libgcc-armv5.a differ