The PX30/RK3326 has 16 KiB SRAM at [0xff0e0000, 0xff0e4000), with the
initial 4 KiB at [0xff0e0000, 0xff0e1000) reserved for BootROM at boot.
SRAM addressing only seem to use 14 bits, meaning that reading from
0xff0e4000+ wraps around and instad reads back data at 0xff0e0000+.
Using a TPL_STACK at 0xff0e4ff0 (16-bytes aligned) means TPL use BootROM
reserved region for its global data, malloc area and runtime stack.
TPL on PX30/RK3326 does not have any use for the malloc area and the
generated GD_SIZE is typically around 304 bytes.
Current memory layout possible looks something like:
[0xff0e0000, 0xff0e4000) 16 KiB SRAM
[0xff0e0000, 0xff0e1000) 4 KiB BROM area
[0xff0e09f0, 0xff0e0ff0) 1536 bytes malloc area (unused)
[0xff0e08c0, 0xff0e09f0) 304 bytes global data
[0xff0e08c0] stack pointer
[0xff0e1000, 0xff0e4000) 12 KiB TPL area
[0xff0e1000, 0xff0e3800) 10 KiB code
Update TPL_STACK to use the top of SRAM address and reduce MALLOC_F_LEN
to 0x0 to avoid overflowing global data and stack into BootROM reserved
region.
After those changes the memory layout looks something like:
[0xff0e0000, 0xff0e4000) 16 KiB SRAM
[0xff0e0000, 0xff0e1000) 4 KiB BROM area
[0xff0e1000, 0xff0e4000) 12 KiB TPL area
[0xff0e1000, 0xff0e3800) 10 KiB code
[0xff0e3ed0, 0xff0e4000) 304 bytes global data
[0xff0e3ed0] stack pointer
[0xff0e3800, 0xff0e3ed0) 1744 bytes stack area
With these changes the TPL_MAX_SIZE can safely be extended to 11 KiB,
leaving enough for the stack to grow down around 720 bytes before it
starts to overlap into TPL.
And with all changes the memory layout looks something like:
[0xff0e0000, 0xff0e4000) 16 KiB SRAM
[0xff0e0000, 0xff0e1000) 4 KiB BROM area
[0xff0e1000, 0xff0e4000) 12 KiB TPL area
[0xff0e1000, 0xff0e3c00) 11 KiB code
[0xff0e3ed0, 0xff0e4000) 304 bytes global data
[0xff0e3ed0] stack pointer
[0xff0e3c00, 0xff0e3ed0) 720 bytes stack area
Signed-off-by: Jonas Karlman <[email protected]>
---
The overflow/wrapping was runtime validated on a RK3326 ODROID-GO Super
by printing out content of [0xff0e0000, 0xff0e5000] and comparing the
initial 4 KiB with the 16-20 KiB and the data matched 1:1.
---
arch/arm/mach-rockchip/px30/Kconfig | 4 ++--
common/spl/Kconfig.tpl | 2 +-
tools/rkcommon.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-rockchip/px30/Kconfig
b/arch/arm/mach-rockchip/px30/Kconfig
index adba1b49a52b..cc0632cf7b2d 100644
--- a/arch/arm/mach-rockchip/px30/Kconfig
+++ b/arch/arm/mach-rockchip/px30/Kconfig
@@ -81,10 +81,10 @@ config TPL_TEXT_BASE
default 0xff0e1000
config TPL_STACK
- default 0xff0e4fff
+ default 0xff0e4000
config TPL_SYS_MALLOC_F_LEN
- default 0x600
+ default 0x0
config DEBUG_UART_CHANNEL
int "Mux channel to use for debug UART2/UART3"
diff --git a/common/spl/Kconfig.tpl b/common/spl/Kconfig.tpl
index a535b61ecd35..cdb9cb188c7c 100644
--- a/common/spl/Kconfig.tpl
+++ b/common/spl/Kconfig.tpl
@@ -129,7 +129,7 @@ config TPL_MAX_SIZE
default 0x2e000 if ROCKCHIP_RK3399
default 0x8000 if ROCKCHIP_RK3288 || ROCKCHIP_RV1126
default 0x7000 if ROCKCHIP_RK322X || ROCKCHIP_RK3328 || ROCKCHIP_RK3368
- default 0x2800 if ROCKCHIP_PX30
+ default 0x2c00 if ROCKCHIP_PX30
default 0x0
help
The maximum size (in bytes) of the TPL stage.
diff --git a/tools/rkcommon.c b/tools/rkcommon.c
index b39777fc0607..872fc21c039d 100644
--- a/tools/rkcommon.c
+++ b/tools/rkcommon.c
@@ -137,7 +137,7 @@ struct spl_info {
};
static struct spl_info spl_infos[] = {
- { "px30", "RK33", 0x2800, false, RK_HEADER_V1 },
+ { "px30", "RK33", 0x2c00, false, RK_HEADER_V1 },
{ "rk3036", "RK30", 0x1000, false, RK_HEADER_V1 },
{ "rk3066", "RK30", 0x8000 - 0x800, true, RK_HEADER_V1 },
{ "rk3128", "RK31", 0x1800, false, RK_HEADER_V1 },
--
2.54.0
