107 lines
2.3 KiB
C
107 lines
2.3 KiB
C
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/* Copyright 2014 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* Tiny charger configuration */
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#include "common.h"
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#include "debug_printf.h"
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#include "ec_commands.h"
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#include "registers.h"
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#include "rsa.h"
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#include "rwsig.h"
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#include "sha256.h"
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#include "system.h"
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#include "task.h"
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#include "usb_pd.h"
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#include "util.h"
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#include "version.h"
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/* Large 768-Byte buffer for RSA computation : could be re-use afterwards... */
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static uint32_t rsa_workbuf[3 * RSANUMWORDS];
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extern void pd_rx_handler(void);
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/* RW firmware reset vector */
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static uint32_t * const rw_rst =
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(uint32_t *)(CONFIG_PROGRAM_MEMORY_BASE+CONFIG_RW_MEM_OFF+4);
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/* External interrupt EXTINT7 for external comparator on PA7 */
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void pd_rx_interrupt(void)
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{
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/* trigger reception handling */
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pd_rx_handler();
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}
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DECLARE_IRQ(STM32_IRQ_EXTI4_15, pd_rx_interrupt, 1);
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static void jump_to_rw(void)
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{
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void (*jump_rw_rst)(void) = (void *)*rw_rst;
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debug_printf("Jump to RW\n");
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/* Disable interrupts */
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asm volatile("cpsid i");
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/* Call RW firmware reset vector */
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jump_rw_rst();
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}
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int is_ro_mode(void)
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{
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return (uint32_t)&jump_to_rw < (uint32_t)rw_rst;
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}
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static int check_rw_valid(void *rw_hash)
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{
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int good;
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/* Check if we have a RW firmware flashed */
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if (*rw_rst == 0xffffffff)
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return 0;
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good = rsa_verify((const struct rsa_public_key *)CONFIG_RO_PUBKEY_ADDR,
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(const uint8_t *)CONFIG_RW_SIG_ADDR,
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rw_hash, rsa_workbuf);
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if (!good) {
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debug_printf("RSA FAILED\n");
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pd_log_event(PD_EVENT_ACC_RW_FAIL, 0, 0, NULL);
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return 0;
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}
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return 1;
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}
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extern void pd_task(void *u);
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int main(void)
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{
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void *rw_hash;
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hardware_init();
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debug_printf("%s started\n",
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is_ro_mode() ? "RO" : "RW");
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/* the RO partition protection is not enabled : do it */
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if (!flash_physical_is_permanently_protected())
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flash_physical_permanent_protect();
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/*
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* calculate the hash of the RW partition
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*
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* Also pre-cache it so we can answer Discover Identity VDM
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* fast enough (in less than 30ms).
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*/
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rw_hash = flash_hash_rw();
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/* Verify RW firmware and use it if valid */
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if (is_ro_mode() && check_rw_valid(rw_hash))
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jump_to_rw();
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/* background loop for PD events */
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pd_task(NULL);
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debug_printf("EXIT!\n");
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/* we should never reach that point */
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system_reset(0);
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return 0;
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}
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