view target-utils/libcommon/uartsel.c @ 435:0a01e1c4ea54

documentation: added some notes about the importance of preserving our /opt/freecalypso private directory hierarchy
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 04 Nov 2018 21:55:19 +0000
parents 2942c5ef76ed
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 = *(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);
}