Add JTAG recovery support into the M2 Porter TPL. This allows the
TPL to be loaded over JTAG, initialize the system, wait for the
JTAG debugger to load U-Boot image into RAM and then resume and
start U-Boot from RAM.
The procedure is as follows:
1) Load u-boot-tpl.bin to 0xe6300000
2) Write magic number 0x1337c0de to 0xe6300020
TPL checks for this particular magic and starts JTAG recovery
if this number is present. This is not present by default.
3) Start U-Boot TPL from 0xe6300000
4) Wait for a message from TPL on UART indicating JTAG boot:
"JTAG boot detected!"
5) Halt the system in JTAG debugger
6) Load U-Boot image (u-boot.img) to 0x4fffffc0
7) Write magic number 0xb33fc0de to 0xe6300024
TPL checks for this particular magic to verify that the U-Boot
image was loaded into DRAM by the JTAG debugger.
8) Resume the system in JTAG debugger
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Add and enable TPL on M2 Porter. The TPL must fit into 16 kiB due
to the Gen2 BootROM restriction. The TPL is running from MERAM and
is capable of performing the initial initialization of PFC, Clock,
GPIO, LBSC, DBSC and QSPI NOR. DBSC is responsible for bringing up
the DDR DRAM access. The TPL is capable of loading the next stage,
U-Boot, from either SPI NOR or UART as a fallback. If either does
provide a valid U-Boot uImage, the system stops, which allows the
operator to load U-Boot ie. via JTAG and start it manually.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Pull the SPL code from porter.c into a separate file in
preparation for the addition of system initialization code.
No functional change.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
