iris/mips/nanonote/stage1.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// mips/nanonote/sdram-setup.ccp: bootstrapping over usb.
// Copyright 2009 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// This runs like the kernel.  In particular, it doesn't want userspace declarations.
#define __KERNEL__
#define dbg_log_char(x) do {} while (0)
#define dbg_log(x) do {} while (0)
#define dbg_log_num(...) do {} while (0)

// Set up gp and sp, jump to start_cpp().
// This must be the first code in the file,
// so also before include jz4740.hh,
// because that defines some static functions which may not be inlined.
asm volatile (".set noreorder\n"
		".globl __start\n"
		".text\n"
		"__start:\n"
		"\tmove $t0, $ra\n"	// 0
		"\tnop\n"		// 4
		"\tbal 1f\n"		// 8
		"\tnop\n"		// 12
		"\t.word _gp\n"		// 16
		"\t.word 0\n"		// 20: This is overwritten in software usbboot mode.
		"1:\n"
		"\tlw $gp, 0($ra)\n"
		"\tlb $a0, 4($ra)\n"
		"\tla $sp, stack + 0x40\n"
		"\tla $t9, start_cpp\n"
		"\tmove $ra, $t0\n"
		"\tjr $t9\n"
		"\tnop\n"
		".set reorder")

#include "jz4740.hh"

void kdebug (unsigned ch):
	while !(UART0_LSR & UARTLSR_TDRQ):
	UART0_TDR = ch 
	while !(UART0_LSR & UARTLSR_TEMT):

extern "C":
	void start_cpp (int skip_memsetup)
	char stack[0x40]

void start_cpp (int skip_memsetup):
	setup_uart ()
	kdebug ('.')
	if !skip_memsetup:
		setup_sdram ()
	kdebug ('!')
	// everything is ok now: return to boot loader to load stage 2.