view fcdev3b-hacks/src/romvecs-insert.S @ 629:3231dd9b38c1

armio.c: make GPIOs 8 & 13 outputs driving 1 on all "classic" targets Calypso GPIOs 8 & 13 are pinmuxed with MCUEN1 & MCUEN2, respectively, and on powerup these pins are MCUEN, i.e., outputs driving 1. TI's code for C-Sample and earlier turns them into GPIOs configured as outputs also driving 1 - so far, so good - but TI's code for BOARD 41 (which covers D-Sample, Leonardo and all real world Calypso devices derived from the latter) switches them from MCUEN to GPIOs, but then leaves them as inputs. Given that the hardware powerup state of these two pins is outputs driving 1, every Calypso board design MUST be compatible with such driving; typically these GPIO signals will be either unused and unconnected or connected as outputs driving some peripheral. Turning these pins into GPIO inputs will result in floating inputs on every reasonably-wired board, thus I am convinced that this configuration is nothing but a bug on the part of whoever wrote this code at TI. This floating input bug had already been fixed earlier for GTA modem and FCDEV3B targets; the present change makes the fix unconditional for all "classic" targets. The newly affected targets are D-Sample, Leonardo, Tango and GTM900.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 02 Jan 2020 05:38:26 +0000
parents 8d9298e0823a
children
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	.text
	.code	32
	.globl	_entry

_entry:	adr	r0, vectors
	ldmia	r0, {r1-r7}
	mov	r0, #0x800000
	stmia	r0, {r1-r7}
	ldr	pc, jumpaddr

vectors:
	.word	0x4000
	.word	0x4004
	.word	0x4008
	.word	0x400C
	.word	0x4010
	.word	0x4014
	.word	0x4018
jumpaddr:
	.word	0x4058