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view target-utils/libcommon/uartsel.c @ 619:f82551c77e58

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libserial-newlnx: ASYNC_LOW_LATENCY patch reverted Reports from Das Signal indicate that loadtools performance on Debian is about the same as on Slackware, and that including or omitting the ASYNC_LOW_LATENCY patch from Serg makes no difference. Because the patch in question does not appear to be necessary, it is being reverted until and unless someone other than Serg reports an actual real-world system on which loadtools operation times are slowed compared to the Mother's Slackware reference and on which Slackware-like performance can be restored by setting the ASYNC_LOW_LATENCY flag.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 27 Feb 2020 01:09:48 +0000
parents 2942c5ef76ed
children
line wrap: on
line source

/*
 * uart_select_init() figures out which UART was used to load us
 * through the boot ROM, and sets things up for us to use the same
 * UART for our communication.
 */

#include "types.h"
#include "romvars.h"
#include "ns16550.h"
#include "halt.h"

extern struct ns16550_regs *uart_base;

static u16 rom_version;
static struct boot_rom_vars *rom_vars;
static char *uart_name;

uart_select_init()
{
	rom_version = *(const u16 *)0x1FFE;

	switch (rom_version) {
	case 0x0200:
		rom_vars = (struct boot_rom_vars *) 0x800504;
		break;
	case 0x0300:
		rom_vars = (struct boot_rom_vars *) 0x800518;
		break;
	default:
		_exit(HALTCODE_BOOTROMVER);
	}

	switch (rom_vars->uart_id) {
	case 0:
		uart_base = (struct ns16550_regs *) 0xFFFF5800;
		uart_name = "MODEM";
		break;
	case 1:
		uart_base = (struct ns16550_regs *) 0xFFFF5000;
		uart_name = "IrDA";
		break;
	default:
		_exit(HALTCODE_INVALIDUART);
	}
}

print_boot_rom_info()
{
	printf("Loaded via boot ROM v%04X, UART %d (%s) at baud rate #%d\n",
		rom_version, rom_vars->uart_id, uart_name,
		rom_vars->baud_rate_code);
	printf("CLKTCXO input autodetected to be %d MHz\n",
		rom_vars->clktcxo_13mhz ? 13 : 26);
}