Microblaze can also have reserved space in DT which u-boot has to avoid to placing self to that location. The same change was done in Zynqmp by commit ce39ee28ec31 ("zynqmp: Do not place u-boot to reserved memory location").
This feature was tested with this memory description on kc705:
memory { device_type = "memory"; reg = <0x80000000 0x40000000>; };
reserved-memory { #address-cells = <1>; #size-cells = <1>; ranges;
alloc@b00000000 { reg = <0xb0000000 0x10000000>; no-map; };
alloc@a8000000 { reg = <0xa8000000 0x00010000>; no-map; }; };
And in U-Boot log you can check u-boot relocation address and reserved locations. U-Boot 2022.01-03974-gb1b4c2dea9b9 (Feb 25 2022 - 11:59:48 +0100)
Model: Xilinx MicroBlaze DRAM: 1 GiB Flash: 128 MiB Loading Environment from nowhere... OK In: serial Out: serial Err: serial Model: Xilinx MicroBlaze Net: AXI EMAC: 40c00000, phyaddr 7, interface gmii eth0: ethernet@40c00000 U-BOOT for microblaze-generic
U-Boot-mONStR> bdi ... DRAM bank = 0x00000000 -> start = 0x80000000 -> size = 0x40000000 ... relocaddr = 0xaff69000 ... lmb_dump_all: memory.cnt = 0x1 memory[0] [0x80000000-0xbfffffff], 0x40000000 bytes flags: 0 reserved.cnt = 0x3 reserved[0] [0xa8000000-0xa800ffff], 0x00010000 bytes flags: 4 reserved[1] [0xafe87bb0-0xafffffff], 0x00178450 bytes flags: 0 reserved[2] [0xb0000000-0xbfffffff], 0x10000000 bytes flags: 4
Signed-off-by: Michal Simek michal.simek@xilinx.com ---
arch/microblaze/include/asm/system.h | 2 ++ .../microblaze-generic/microblaze-generic.c | 21 +++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/arch/microblaze/include/asm/system.h b/arch/microblaze/include/asm/system.h index 3107748d3bdb..050a8b407636 100644 --- a/arch/microblaze/include/asm/system.h +++ b/arch/microblaze/include/asm/system.h @@ -23,6 +23,8 @@ #endif #include <asm/ptrace.h>
+#define MMU_SECTION_SIZE (1 * 1024 * 1024) + #define prepare_to_switch() do { } while (0)
/* diff --git a/board/xilinx/microblaze-generic/microblaze-generic.c b/board/xilinx/microblaze-generic/microblaze-generic.c index a427ac94a170..f58ecd1590c9 100644 --- a/board/xilinx/microblaze-generic/microblaze-generic.c +++ b/board/xilinx/microblaze-generic/microblaze-generic.c @@ -14,6 +14,8 @@ #include <config.h> #include <env.h> #include <init.h> +#include <image.h> +#include <lmb.h> #include <log.h> #include <asm/global_data.h> #include <dm/lists.h> @@ -36,6 +38,25 @@ int dram_init(void) return 0; };
+ulong board_get_usable_ram_top(ulong total_size) +{ + phys_size_t size; + phys_addr_t reg; + struct lmb lmb; + + /* found enough not-reserved memory to relocated U-Boot */ + lmb_init(&lmb); + lmb_add(&lmb, gd->ram_base, gd->ram_size); + boot_fdt_add_mem_rsv_regions(&lmb, (void *)gd->fdt_blob); + size = ALIGN(CONFIG_SYS_MALLOC_LEN + total_size, MMU_SECTION_SIZE); + reg = lmb_alloc(&lmb, size, MMU_SECTION_SIZE); + + if (!reg) + reg = gd->ram_top - size; + + return reg + size; +} + int board_late_init(void) { ulong max_size;