From 8a114bac1145359f3953ce70f049a6be71df5300 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 12 May 2014 23:18:41 -0700 Subject: [PATCH] altos/flash-loader: Check memory addresses against flash space This validates memory read/write requests to make sure they are within the available flash memory space. This also reports the flash base and bounds addresses in the 'version' command so that the loader can validate the image before attempting to write it. Signed-off-by: Keith Packard --- src/product/ao_flash_task.c | 39 +++++++++++++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 4 deletions(-) diff --git a/src/product/ao_flash_task.c b/src/product/ao_flash_task.c index 6cb308e1..9a12add6 100644 --- a/src/product/ao_flash_task.c +++ b/src/product/ao_flash_task.c @@ -79,6 +79,14 @@ ao_block_erase(void) ao_flash_erase_page(p); } +static int +ao_block_valid_address(uint32_t addr) +{ + if ((uint32_t) AO_BOOT_APPLICATION_BASE <= addr && addr <= (uint32_t) AO_BOOT_APPLICATION_BOUND - 256) + return 1; + return 0; +} + static void ao_block_write(void) { @@ -87,12 +95,10 @@ ao_block_write(void) uint8_t data[256]; uint16_t i; - if (addr < (uint32_t) AO_BOOT_APPLICATION_BASE) { - ao_put_string("Invalid address\n"); - return; - } for (i = 0; i < 256; i++) data[i] = ao_usb_getchar(); + if (!ao_block_valid_address(addr)) + return; ao_flash_page(p, (void *) data); } @@ -104,18 +110,43 @@ ao_block_read(void) uint16_t i; uint8_t c; + if (!ao_block_valid_address(addr)) { + for (i = 0; i < 256; i++) + ao_usb_putchar(0xff); + return; + } for (i = 0; i < 256; i++) { c = *p++; ao_usb_putchar(c); } } +static inline void +hexchar(uint8_t c) +{ + if (c > 10) + c += 'a' - ('9' + 1); + ao_usb_putchar(c + '0'); +} + +static void +ao_put_hex(uint32_t u) +{ + int8_t i; + for (i = 28; i >= 0; i -= 4) + hexchar((u >> i) & 0xf); +} + static void ao_show_version(void) { ao_put_string("altos-loader"); ao_put_string("\nmanufacturer "); ao_put_string(ao_manufacturer); ao_put_string("\nproduct "); ao_put_string(ao_product); + ao_put_string("\nflash-range "); + ao_put_hex((uint32_t) AO_BOOT_APPLICATION_BASE); + ao_usb_putchar(' '); + ao_put_hex((uint32_t) AO_BOOT_APPLICATION_BOUND); ao_put_string("\nsoftware-version "); ao_put_string(ao_version); ao_put_string("\n"); } -- 2.30.2