view target-utils/libcommon/uartsel.c @ 992:a7b0b426f9ca

target-utils: boot ROM UART autodetection revamped The new implementation should work with both the familiar Calypso C035 boot ROM version found in our regular targets as well as the older Calypso F741979B version found on the vintage D-Sample board.
author Mychaela Falconia <falcon@ivan.Harhan.ORG>
date Wed, 30 Dec 2015 21:28:41 +0000
parents 40f607bb0a2c
children
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/*
 * 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 = *(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);
}