From b595edb1039fd158112951f94f3a18a35dc587b5 Mon Sep 17 00:00:00 2001 From: Emard Date: Sun, 17 Feb 2019 13:02:24 +0100 Subject: [PATCH] manual multiboot note update --- doc/MANUAL.md | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/doc/MANUAL.md b/doc/MANUAL.md index c188616..f880291 100644 --- a/doc/MANUAL.md +++ b/doc/MANUAL.md @@ -232,14 +232,16 @@ and "tinyfpgasp" application can be used to write or read arbitrary image to FPGA SPI config FLASH. User bitstream should be uploaded to byte address 0x200000 of SPI config -FLASH. Bootloader in multiboot mode resides in multiple copies on SPI config +FLASH at 12/25/45F (I'm not sure for 85F). +Bootloader in multiboot mode resides in multiple copies on SPI config FLASH chip. "primary" bootloader image is at byte address 0 of SPI config FLASH, "golden" bootloader image is at 0x140000 address on 45F chip but its location varies on various sizes of FPGA 12/25/45/85F. At the last 256 bytes of FLASH are some special FPGA lattice boot state machine commands -(like some primitive CPU assemlby) that setups and controls multiboot -function. Try not to overwrite any of boot realted areas with something +(detailed meaning and format not yet known, it's like some primitive CPU assemlby) +that setups and controls multiboot function. +Try not to overwrite any of boot related areas with something else otherwise US1 or JTAG recovery will be required. # Programming over JTAG header