HACK! ARM: allow a bootloader to be embedded and do it on efm32

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

3 files changed, 265 insertions, 0 deletions

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 6f57cb94367f..05f562f21afa 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -86,6 +86,11 @@ SECTIONS
 #else
 	. = PAGE_OFFSET + TEXT_OFFSET;
 #endif
+
+	.bootloader : {
+		*(.bootloader)
+	}
+
 	.head.text : {
 		_text = .;
 		HEAD_TEXT
diff --git a/arch/arm/mach-efm32/Makefile b/arch/arm/mach-efm32/Makefile
index b295a74e0a07..b28d37ca5743 100644
--- a/arch/arm/mach-efm32/Makefile
+++ b/arch/arm/mach-efm32/Makefile
@@ -1,3 +1,11 @@
+ifeq ($(CONFIG_FLASH_MEM_BASE),0x00000000)
+obj-y += bootloader.o
+endif
+
+ifeq ($(CONFIG_USE_OF),y)
+$(obj)/bootloader.o: $(obj)/../boot/dts/efm32gg-dk3750.dtb
+endif
+
 obj-y += common.o dtmachine.o
 
 obj-$(CONFIG_PM) += pm.o
diff --git a/arch/arm/mach-efm32/bootloader.S b/arch/arm/mach-efm32/bootloader.S
new file mode 100644
index 000000000000..d4dbf0bd8004
--- /dev/null
+++ b/arch/arm/mach-efm32/bootloader.S
@@ -0,0 +1,252 @@
+#if defined(CONFIG_OF)
+#define EFM32_USE_OF
+#endif
+#define EFM32_DT_IN_SRAM
+
+/* UART1 */
+#define UARTBASE 0x4000e400
+#define UARTLOCATION 2
+
+	.thumb
+
+	.section ".bootloader","ax"
+
+	/* M3 Vector table */
+	.int 0x10001000		@ Initial SP value
+	.int reset + 1		@ Reset
+
+reset:
+	/* init external RAM, serial port, EBI and stuff */
+	adr	r0, reginit
+1:
+	ldr	r1, [r0]
+	ldr	r2, [r0, #4]
+	str	r2, [r1]
+	add	r0, #8
+	cmp	r0, #(reginit_end)
+	blo	1b
+
+
+	/* init some BC registers */
+	adr	r0, bcinit
+1:
+	ldrh	r1, [r0]
+	ldrh	r2, [r0, #2]
+	add	r1, r1, #0x80000000
+	strh	r2, [r1]
+	add	r0, #4
+	cmp	r0, #(bcinit_end)
+	blo	1b
+
+	/* give mux some time to enable the level shifter */
+	ldr	r0, =0x4000
+1:	subs	r0, r0, #1
+	bne	1b
+
+	ldr	r0, =(UARTBASE + 0x34)
+	mov	r1, 0x55
+	str	r1, [r0]
+
+	/* Zero PSRAM */
+	ldr	r0, =(0x88000000)
+	ldr	r1, =(0x88400000)
+	mov	r2, #0
+	mov	r3, #0
+	mov	r4, #0
+	mov	r5, #0
+1:	stmia	r0!, {r2-r5}
+	cmp	r0, r1
+	bcc	1b
+
+	/* assert zeroing succeeded */
+	ldr	r6, =(UARTBASE + 0x34)
+	mov	r7, #'<'
+	str	r7, [r6]
+	mov	r7, #'*'
+	ldr     r0, =(0x88000000)
+1:	ldmia	r0!, {r2-r5}
+	orr	r2, r3
+	orr	r4, r5
+	orr	r2, r4
+	cmp	r2, #0
+	it	ne
+	strne	r7, [r6]
+	cmp	r0, r1
+	bcc	1b
+	mov	r7, #'>'
+	str	r7, [r6]
+
+#if defined(EFM32_USE_OF) && defined(EFM32_DT_IN_SRAM)
+#define dtbaddr 0x10000000
+	ldr	r0, =(dtbaddr)
+	ldr	r1, =(dtb)
+	adr	r2, dtbend
+	subs	r2, r2, r1
+	bl	_memcpy
+#endif
+	/* detect machine type; easy we know this is an efm32gg_dk3750 */
+	movw	r0, #0
+	movw	r1, #0xf11	@ machid for efm32gg_dk3750
+#ifdef EFM32_USE_OF
+#ifdef EFM32_DT_IN_SRAM
+	ldr	r2, =(dtbaddr)
+#else
+	adr	r2, dtb
+#endif
+#else
+	adr	r2, ataglist
+#endif
+	movw	r3, #0
+	movw	r4, #0
+	movw	r5, #0
+	movw	r6, #0
+	movw	r7, #0
+
+	b	stext
+
+#ifdef EFM32_DT_IN_SRAM
+_memcpy:
+	@ copies r2 bytes from r1 to r0 with r2 > 0
+1:
+	ldrb	r3, [r1], #1
+	strb	r3, [r0], #1
+	subs	r2, #1
+	bhi	1b
+	bx	lr
+#endif
+
+	.ltorg
+
+	.align	3
+	/* register value pairs to initialize the machine */
+	.type reginit, %object
+reginit:
+	/* clocks */
+	.int	0x400C8020, 0x00000004		@ CMU_OSCENCMD |= HFXOEN
+
+	.int	0x400c8008, 0x00000100		@ CMU_HFPERCLKDIV, reset default
+	.int	0x43900814, 0x00000001		@ CMU_HFCORECLKEN0 |= EBI via bitband
+	.int	0x439008b4, 0x00000001		@ CMU_HFPERCLKEN0 |= GPIO via bitband
+	.int	0x43900884, 0x00000001		@ CMU_HFPERCLKEN0 |= USART1 via bitband
+	.int	0x43900890, 0x00000001		@ CMU_HFPERCLKEN0 |= UART1 via bitband
+
+	/* XXX */
+	.int	0x439008c0, 0x00000001		@ CMU_HFPERCLKEN0 |= ADC via bitband
+
+	/* pinmuxing */
+	.int	0x40006000, 0x00000000		@ GPIO_PA_CTRL, reset default
+	.int	0x40006014, 0x0000807f		@ GPIO_PA_DOUTCLR; EBI AD8..15 set dataout to 0
+	.int	0x40006004, 0x04444444		@ GPIO_PA_MODEL; EBI AD9..15 set mode=pushpull
+	.int	0x40006008, 0x40000000		@ GPIO_PA_MODEH; EBI AD8 set mode=pushpull
+	.int	0x40006024, 0x00000000		@ GPIO_PB_CTRL, reset default
+	.int	0x40006038, 0x00008000		@ GPIO_PB_DOUTCLR; EBI mode on PB15 MCU_EBI_CONNECT (0)
+	.int	0x40006038, 0x0000007f		@ GPIO_PB_DOUTCLR; EBI A16-22
+	.int	0x40006028, 0x04444444		@ GPIO_PB_MODEL; EBI A16-22
+	.int	0x40006034, 0x00000200		@ GPIO_PB_DOUTSET; set UART_TX to avoid false start
+	.int	0x4000602c, 0x40000140		@ GPIO_PB_MODEH; MCU_EBI_CONNECT -> output, UART_TX, UART_RX
+
+	.int	0x40006048, 0x00000000		@ GPIO_PC_CTRL, reset default
+	.int	0x4000605c, 0x00000001		@ GPIO_PC_DOUTCLR; PC11 (EBI_ALE)
+	.int	0x40006050, 0x00004000		@ GPIO_PC_MODEH; PC11: Push-pull output
+	.int	0x4000606c, 0x00000000		@ GPIO_PD_CTRL, reset default
+	.int	0x4000607c, 0x00003e08		@ GPIO_PD_DOUTSET, EBI CS0-3, spiconnect set dataout to 1; ETH_SPI_#CS (D3)
+	.int	0x40006080, 0x00000007		@ GPIO_PD_DOUTCLR, ETH_SPI_{TX, RX, CLK}
+	.int	0x40006070, 0x00004414		@ GPIO_PD_MODEL; ETH_SPI_
+	.int	0x40006074, 0x00444440		@ GPIO_PD_MODEH; EBI CS0-3, spiconnect set mode=pushpull
+	.int	0x40006090, 0x00000000		@ GPIO_PE_CTRL, reset default
+	.int	0x400060a0, 0x00000001		@ GPIO_PE_DOUTSET; FPGA irq line
+	.int	0x400060a4, 0x0000ff00		@ GPIO_PE_DOUTCLR; EBI AD0..7 set dataout to 0
+	.int	0x40006094, 0x00000002		@ GPIO_PE_MODEL; FPGA irq line set mode=inputpull
+	.int	0x40006098, 0x44444444		@ GPIO_PE_MODEH; EBI AD0..7 set mode=pushpull
+
+	.int	0x400060b4, 0x00000000		@ GPIO_PF_CTRL, reset default
+	.int	0x400060c8, 0x000003c0		@ GPIO_PF_DOUTCLR; EBI Wen+Ren set dataout to 0
+	.int	0x400060b8, 0x44000000		@ GPIO_PF_MODEL; EBI Byte Lane 0 support BL0/BL1
+	.int	0x400060bc, 0x00000044		@ GPIO_PF_MODEH; EBI WEN, REN
+
+	.int	0x40006100, 0x00000004		@ GPIO_EXTIPSELL: select port E for irq 0
+	.int	0x4000610c, 0x00000001		@ GPIO_EXTIFALL: trigger for falling FPGA irq line
+	.int	0x4000611c, 0x0000ffff		@ ? GPIO_IFC: clear all irqs
+	.int	0x40006110, 0x00000001		@ GPIO_IEN: enable irq 0
+
+	/* EBI */
+	.int	0x40008000, 0x4f00d051		@ EBI_CTRL, enable ITS, mode0=mode2=mode3=D16A16ALE, bl0-3, noidle[023]
+	/* EBI PSRAM */
+	.int	0x40008028, 0x10000000		@ EBI_ADDRTIMING2; HALFALE
+	.int	0x4000802c, 0x20000400		@ EBI_RDTIMING2; Prefetch, StrobeCycles = 4, HoldCycles = SetupCycles = 0
+	.int	0x40008030, 0x00000200		@ EBI_WRTIMING2; StrobeCycles = 2, HoldCycles = SetupCycles = 0
+	.int	0x40008034, 0x00000008		@ EBI_POLARITY2, ARDY_, ALE, WE_, RE_, CS_, BL_
+
+	/* Board Control FPGA */
+	.int	0x40008004, 0x10000303		@ EBI_ADDRTIMING; HALFALE, HoldCycles = SetupCycles = 3
+	.int	0x40008008, 0x00030703		@ EBI_RDTIMING; StrobeCycles = 7, HoldCycles = SetupCycles = 3
+	.int	0x4000800c, 0x00030703		@ EBI_WRTIMING; StrobeCycles = 7, HoldCycles = SetupCycles = 3
+	.int	0x40008010, 0x00000008		@ EBI_POLARITY, ARDY_, ALE, WE_, RE_, CS_, BL_
+
+	/* external NOR flash */
+	.int	0x40008038, 0x10000000		@ EBI_ADDRTIMING3; HALFALE, HoldCycles = SetupCycles = 0
+	.int	0x4000803c, 0x00000700		@ EBI_RDTIMING3; StrobeCycles = 7, HoldCycles = SetupCycles = 0
+	.int	0x40008040, 0x00000200		@ EBI_WRTIMING3; StrobeCycles = 2, HoldCycles = SetupCycles =0
+	.int	0x40008044, 0x00000008		@ EBI_POLARITY3, ARDY_, ALE, WE_, RE_, CS_, BL_
+
+	.int	0x40008014, 0x105e00bb		@ EBI_ROUTE
+	.int	0x40008000, 0x4f00dd51		@ EBI_CTRL, enable ITS, mode0=mode2=mode3=D16A16ALE, bl0-3, noidle[023], bank[023]en
+
+	.int	UARTBASE + 0x00, 0x00000000		@ UART1_CTRL
+	.int	UARTBASE + 0x04, 0x00001005		@ UART1_FRAME
+	.int	UARTBASE + 0x14, 0x00001900		@ UART1_CLKDIV
+	.int	UARTBASE + 0x0c, 0x00000c04		@ UART1_CMD
+	.int	UARTBASE + 0x54, 0x00000003 + (UARTLOCATION << 8)		@ UART1_ROUTE
+	.int	0x400c8024, 0x00000002		@ CMU_CMD = HFCLKSEL_HFXO
+
+reginit_end:
+	.size reginit, . - reginit
+
+	.align	3
+	/* register value pairs to initialize the board controller */
+	.type bcinit, %object
+bcinit:
+	.short	0x0018, 0x1300			@ enable UART mux and ETH
+	.short	0x0014, 0x0001			@ /
+	.short	0x001a, 0x0001			@ ETH
+
+bcinit_end:
+	.size bcinit, . - bcinit
+
+	.align 3
+#ifdef EFM32_USE_OF
+	.type dtb, %object
+dtb:
+	.incbin "arch/arm/boot/dts/efm32gg-dk3750.dtb"
+dtbend:
+	.size dtb, . - dtb
+	.align 3
+
+#else /* ifdef CONFIG_OF */
+
+	.type ataglist, %object
+ataglist:
+	/* ATAG_CORE */
+	.int	0x00000005		/* .size */
+	.int	0x54410001		/* .tag = ATAG_CORE */
+	.int	0x00000001		/* .flags */
+	.int	0x00001000		/* .pagesize */
+	.int	0x000000ff		/* .rootdev */
+	/* ATAG_MEM */
+	.int	0x00000004		/* .size */
+	.int	0x54410002		/* .tag = ATAG_MEM */
+	.int	0x00400000		/* .size = 4 MiB */
+	.int	0x88000000		/* .start = SRAM_BASE */
+	/* ATAG_CMDLINE */
+cmdline:
+	.int	(cmdline_end - cmdline) >> 2	/* .size */
+	.int	0x54410009		/* .tag = ATAG_CMDLINE */
+	.asciz	"console=ttyefm4,115200 ignore_loglevel ihash_entries=64 dhash_entries=64 rootfstype=romfs init=/linuxrc uclinux.physaddr=0x8c000000 root=/dev/mtdblock0 earlyprintk"
+	.align	2, 0
+cmdline_end:
+	/* ATAG_NONE */
+	.int	0x00000000	/* .size */
+	.int	0x00000000	/* .tag = ATAG_NONE */
+ataglist_end:
+	.size ataglist, . - ataglist
+#endif /* ifdef CONFIG_OF / else */