diff --git a/contrib/loaders/flash/fespi/fespi.S b/contrib/loaders/flash/fespi/fespi.S deleted file mode 100644 index d68e65ef8..000000000 --- a/contrib/loaders/flash/fespi/fespi.S +++ /dev/null @@ -1,99 +0,0 @@ -#define SPIFLASH_READ_STATUS 0x05 // Read Status Register -#define SPIFLASH_BSY_BIT 0x00000001 // WIP Bit of SPI SR on SMI SR - -// Register offsets -#define FESPI_REG_FMT 0x40 -#define FESPI_REG_TXFIFO 0x48 -#define FESPI_REG_RXFIFO 0x4c -#define FESPI_REG_IP 0x74 - -// Fields -#define FESPI_IP_TXWM 0x1 -#define FESPI_FMT_DIR(x) (((x) & 0x1) << 3) - -// To enter, jump to the start of command_table (ie. offset 0). -// a0 - FESPI base address -// a1 - start address of buffer - -// The buffer contains a "program" in byte sequences. The first byte in a -// sequence determines the operation. Some operation will read more data from -// the program, while some will not. The operation byte is the offset into -// command_table, so eg. 4 means exit, 8 means transmit, and so on. - - .global _start -_start: -command_table: - j main // 0 - ebreak // 4 - j tx // 8 - j txwm_wait // 12 - j write_reg // 16 - j wip_wait // 20 - j set_dir // 24 - -// Execute the program. -main: - lbu t0, 0(a1) - addi a1, a1, 1 - la t1, command_table - add t0, t0, t1 - jr t0 - -// Read 1 byte the contains the number of bytes to transmit. Then read those -// bytes from the program and transmit them one by one. -tx: - lbu t1, 0(a1) // read number of bytes to transmit - addi a1, a1, 1 -1: lw t0, FESPI_REG_TXFIFO(a0) // wait for FIFO clear - bltz t0, 1b - lbu t0, 0(a1) // Load byte to write - sw t0, FESPI_REG_TXFIFO(a0) - addi a1, a1, 1 - addi t1, t1, -1 - bgtz t1, 1b - j main - -// Wait until TXWM is set. -txwm_wait: -1: lw t0, FESPI_REG_IP(a0) - andi t0, t0, FESPI_IP_TXWM - beqz t0, 1b - j main - -// Read 1 byte that contains the offset of the register to write, and 1 byte -// that contains the data to write. -write_reg: - lbu t0, 0(a1) // read register to write - add t0, t0, a0 - lbu t1, 1(a1) // read value to write - addi a1, a1, 2 - sw t1, 0(t0) - j main - -wip_wait: - li a2, SPIFLASH_READ_STATUS - jal txrx_byte - // discard first result -1: li a2, 0 - jal txrx_byte - andi t0, a2, SPIFLASH_BSY_BIT - bnez t0, 1b - j main - -txrx_byte: // transmit the byte in a2, receive a bit into a2 - lw t0, FESPI_REG_TXFIFO(a0) // wait for FIFO clear - bltz t0, txrx_byte - sw a2, FESPI_REG_TXFIFO(a0) -1: lw a2, FESPI_REG_RXFIFO(a0) - bltz a2, 1b - ret - -set_dir: - lw t0, FESPI_REG_FMT(a0) - li t1, ~(FESPI_FMT_DIR(0xFFFFFFFF)) - and t0, t0, t1 - lbu t1, 0(a1) // read value to OR in - addi a1, a1, 1 - or t0, t0, t1 - sw t0, FESPI_REG_FMT(a0) - j main diff --git a/contrib/loaders/flash/fespi/riscv.lds b/contrib/loaders/flash/fespi/riscv.lds index 524a77c1f..77fe0e558 100644 --- a/contrib/loaders/flash/fespi/riscv.lds +++ b/contrib/loaders/flash/fespi/riscv.lds @@ -2,7 +2,7 @@ OUTPUT_ARCH( "riscv" ) SECTIONS { - . = 0x80000000; + . = 0x12340000; .text : { *(.text.entry) diff --git a/contrib/loaders/flash/fespi/riscv_wrapper.S b/contrib/loaders/flash/fespi/riscv_wrapper.S index c3f11ece6..4f632a76e 100644 --- a/contrib/loaders/flash/fespi/riscv_wrapper.S +++ b/contrib/loaders/flash/fespi/riscv_wrapper.S @@ -11,10 +11,7 @@ .section .text.entry .global _start _start: - /* Spell out `la sp, stack_end` because otherwise the assembler won't - generate position-independent code. */ -1: auipc sp, %pcrel_hi(stack_end) # load stack_end(hi) - addi sp, sp, %pcrel_lo(1b) # load stack_end(lo) + lla sp, stack_end jal flash_fespi ebreak