view target-utils/libbase/osmodelay.S @ 995:74024eb17e04

fc-loadtool help: improve language regarding 16 MiB flash chips In FC project history, 16 MiB flash originally meant Pirelli DP-L10. Then we got FCDEV3B with the same flash (our own design), but now we are discovering more Calypso devices that used such large flash, both late Calypso era (Sony Ericsson K2x0) as well as much earlier ones (FIC FLUID devices.txt file with 2004 dates, Leonardo+ rev 5). Hence we need to migrate to more generic or neutral language in associated documentation, without giving elevated status to specific examples that drove our early project history.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 03 Dec 2023 21:11:12 +0000
parents e7502631a0f9
children
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/*
 * This assembly module provides a replica of OsmocomBB's bogo-millisecond
 * delay_ms() function.  It is literally a copy of what OsmocomBB's delay_ms()
 * compiles to with their gcc version and their optimization settings, as seen
 * by doing arm-elf-objdump on their lib/delay.o.
 *
 * This hack is intended for those cases where we have to copy OsmocomBB's
 * black magic voodoo operations with no ability to understand what is actually
 * needed, such as SPCA552E initialization on the Pirelli DP-L10.
 */

	.text
	.code	32
	.globl	osmo_delay_ms
osmo_delay_ms:
	mov     r3, #0
	sub     sp, sp, #4
	str     r3, [sp]
	ldr     r3, =1300
	mul     r3, r0, r3
	b       2f
1:	ldr     r2, [sp]
	ldr     r2, [sp]
	add     r2, r2, #1
	str     r2, [sp]
2:	ldr     r2, [sp]
	cmp     r2, r3
	bcc     1b
	add     sp, sp, #4
	bx      lr