[U-Boot] [UNTESTED PATCH] ARM: orion5x: fix use of callee-saved registers in lowloevel_init
Chris Packham
judge.packham at gmail.com
Mon May 7 21:25:39 UTC 2018
On Mon, May 7, 2018 at 10:11 PM Mans Rullgard <mans at mansr.com> wrote:
> The lowlevel_init function uses r4 and r6 without preserving their
> values as required by the AAPCS. Use r0 and r2 instead as these
> are call-clobbered.
> Signed-off-by: Mans Rullgard <mans at mansr.com>
> ---
> arch/arm/mach-orion5x/lowlevel_init.S | 168 +++++++++++++-------------
> 1 file changed, 84 insertions(+), 84 deletions(-)
> diff --git a/arch/arm/mach-orion5x/lowlevel_init.S
b/arch/arm/mach-orion5x/lowlevel_init.S
> index 3f38f36ff294..a4e113601013 100644
> --- a/arch/arm/mach-orion5x/lowlevel_init.S
> +++ b/arch/arm/mach-orion5x/lowlevel_init.S
> @@ -72,67 +72,67 @@ lowlevel_init:
> #ifdef CONFIG_SPL_BUILD
> - /* Use 'r4 as the base for internal register accesses */
> - ldr r4, =ORION5X_REGS_PHY_BASE
> + /* Use 'r2 as the base for internal register accesses */
> + ldr r2, =ORION5X_REGS_PHY_BASE
> /* move internal registers from the default 0xD0000000
> * to their intended location, defined by SoC */
> ldr r3, =0xD0000000
> add r3, r3, #0x20000
> - str r4, [r3, #0x80]
> + str r2, [r3, #0x80]
> /* Use R3 as the base for DRAM registers */
> - add r3, r4, #0x01000
> + add r3, r2, #0x01000
> /*DDR SDRAM Initialization Control */
> - ldr r6, =0x00000001
> - str r6, [r3, #0x480]
> + ldr r0, =0x00000001
> + str r0, [r3, #0x480]
> /* Use R3 as the base for PCI registers */
> - add r3, r4, #0x31000
> + add r3, r2, #0x31000
> /* Disable arbiter */
> - ldr r6, =0x00000030
> - str r6, [r3, #0xd00]
> + ldr r0, =0x00000030
> + str r0, [r3, #0xd00]
> /* Use R3 as the base for DRAM registers */
> - add r3, r4, #0x01000
> + add r3, r2, #0x01000
> /* set all dram windows to 0 */
> - mov r6, #0
> - str r6, [r3, #0x504]
> - str r6, [r3, #0x50C]
> - str r6, [r3, #0x514]
> - str r6, [r3, #0x51C]
> + mov r0, #0
> + str r0, [r3, #0x504]
> + str r0, [r3, #0x50C]
> + str r0, [r3, #0x514]
> + str r0, [r3, #0x51C]
> /* 1) Configure SDRAM */
> - ldr r6, =SDRAM_CONFIG
> - str r6, [r3, #0x400]
> + ldr r0, =SDRAM_CONFIG
> + str r0, [r3, #0x400]
> /* 2) Set SDRAM Control reg */
> - ldr r6, =SDRAM_CONTROL
> - str r6, [r3, #0x404]
> + ldr r0, =SDRAM_CONTROL
> + str r0, [r3, #0x404]
> /* 3) Write SDRAM address control register */
> - ldr r6, =SDRAM_ADDR_CTRL
> - str r6, [r3, #0x410]
> + ldr r0, =SDRAM_ADDR_CTRL
> + str r0, [r3, #0x410]
> /* 4) Write SDRAM bank 0 size register */
> - ldr r6, =SDRAM_BANK0_SIZE
> - str r6, [r3, #0x504]
> + ldr r0, =SDRAM_BANK0_SIZE
> + str r0, [r3, #0x504]
> /* keep other banks disabled */
> /* 5) Write SDRAM open pages control register */
> - ldr r6, =SDRAM_OPEN_PAGE_EN
> - str r6, [r3, #0x414]
> + ldr r0, =SDRAM_OPEN_PAGE_EN
> + str r0, [r3, #0x414]
> /* 6) Write SDRAM timing Low register */
> - ldr r6, =SDRAM_TIME_CTRL_LOW
> - str r6, [r3, #0x408]
> + ldr r0, =SDRAM_TIME_CTRL_LOW
> + str r0, [r3, #0x408]
> /* 7) Write SDRAM timing High register */
> - ldr r6, =SDRAM_TIME_CTRL_HI
> - str r6, [r3, #0x40C]
> + ldr r0, =SDRAM_TIME_CTRL_HI
> + str r0, [r3, #0x40C]
> /* 8) Write SDRAM mode register */
> /* The CPU must not attempt to change the SDRAM Mode register
setting */
> @@ -143,73 +143,73 @@ lowlevel_init:
> /* and then sets SDRAM Mode register to its new value.
*/
> /* 8.1 write 'nop' to SDRAM operation */
> - ldr r6, =SDRAM_OP_NOP
> - str r6, [r3, #0x418]
> + ldr r0, =SDRAM_OP_NOP
> + str r0, [r3, #0x418]
> /* 8.2 poll SDRAM operation until back in 'normal' mode. */
> 1:
> - ldr r6, [r3, #0x418]
> - cmp r6, #0
> + ldr r0, [r3, #0x418]
> + cmp r0, #0
> bne 1b
> /* 8.3 Now its safe to write new value to SDRAM Mode register
*/
> - ldr r6, =SDRAM_MODE
> - str r6, [r3, #0x41C]
> + ldr r0, =SDRAM_MODE
> + str r0, [r3, #0x41C]
> /* 8.4 Set new mode */
> - ldr r6, =SDRAM_OP_SETMODE
> - str r6, [r3, #0x418]
> + ldr r0, =SDRAM_OP_SETMODE
> + str r0, [r3, #0x418]
> /* 8.5 poll SDRAM operation until back in 'normal' mode. */
> 2:
> - ldr r6, [r3, #0x418]
> - cmp r6, #0
> + ldr r0, [r3, #0x418]
> + cmp r0, #0
> bne 2b
> /* DDR SDRAM Address/Control Pads Calibration */
> - ldr r6, [r3, #0x4C0]
> + ldr r0, [r3, #0x4C0]
> /* Set Bit [31] to make the register writable */
> - orr r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - str r6, [r3, #0x4C0]
> + orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + str r0, [r3, #0x4C0]
> - bic r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - bic r6, r6, #SDRAM_PAD_CTRL_TUNE_EN
> - bic r6, r6, #SDRAM_PAD_CTRL_DRVN_MASK
> - bic r6, r6, #SDRAM_PAD_CTRL_DRVP_MASK
> + bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + bic r0, r0, #SDRAM_PAD_CTRL_TUNE_EN
> + bic r0, r0, #SDRAM_PAD_CTRL_DRVN_MASK
> + bic r0, r0, #SDRAM_PAD_CTRL_DRVP_MASK
> /* Get the final N locked value of driving strength [22:17] */
> - mov r1, r6
> + mov r1, r0
> mov r1, r1, LSL #9
> mov r1, r1, LSR #26 /* r1[5:0]<DrvN> = r3[22:17]<LockN> */
> orr r1, r1, r1, LSL #6 /* r1[11:6]<DrvP> = r1[5:0]<DrvN> */
> /* Write to both <DrvN> bits [5:0] and <DrvP> bits [11:6] */
> - orr r6, r6, r1
> - str r6, [r3, #0x4C0]
> + orr r0, r0, r1
> + str r0, [r3, #0x4C0]
> /* DDR SDRAM Data Pads Calibration */
> - ldr r6, [r3, #0x4C4]
> + ldr r0, [r3, #0x4C4]
> /* Set Bit [31] to make the register writable */
> - orr r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - str r6, [r3, #0x4C4]
> + orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + str r0, [r3, #0x4C4]
> - bic r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - bic r6, r6, #SDRAM_PAD_CTRL_TUNE_EN
> - bic r6, r6, #SDRAM_PAD_CTRL_DRVN_MASK
> - bic r6, r6, #SDRAM_PAD_CTRL_DRVP_MASK
> + bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + bic r0, r0, #SDRAM_PAD_CTRL_TUNE_EN
> + bic r0, r0, #SDRAM_PAD_CTRL_DRVN_MASK
> + bic r0, r0, #SDRAM_PAD_CTRL_DRVP_MASK
> /* Get the final N locked value of driving strength [22:17] */
> - mov r1, r6
> + mov r1, r0
> mov r1, r1, LSL #9
> mov r1, r1, LSR #26
> orr r1, r1, r1, LSL #6 /* r1[5:0] = r3[22:17]<LockN> */
> /* Write to both <DrvN> bits [5:0] and <DrvP> bits [11:6] */
> - orr r6, r6, r1
> + orr r0, r0, r1
> - str r6, [r3, #0x4C4]
> + str r0, [r3, #0x4C4]
> /* Implement Guideline (GL# MEM-3) Drive Strength Value */
> /* Relevant for: 88F5181-A1/B0/B1 and 88F5281-A0/B0 */
> @@ -217,37 +217,37 @@ lowlevel_init:
> ldr r1, =DDR1_PAD_STRENGTH_DEFAULT
> /* Enable writes to DDR SDRAM Addr/Ctrl Pads Calibration register
*/
> - ldr r6, [r3, #0x4C0]
> - orr r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - str r6, [r3, #0x4C0]
> + ldr r0, [r3, #0x4C0]
> + orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + str r0, [r3, #0x4C0]
> /* Correct strength and disable writes again */
> - bic r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - bic r6, r6, #SDRAM_PAD_CTRL_DRV_STR_MASK
> - orr r6, r6, r1
> - str r6, [r3, #0x4C0]
> + bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + bic r0, r0, #SDRAM_PAD_CTRL_DRV_STR_MASK
> + orr r0, r0, r1
> + str r0, [r3, #0x4C0]
> /* Enable writes to DDR SDRAM Data Pads Calibration register */
> - ldr r6, [r3, #0x4C4]
> - orr r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - str r6, [r3, #0x4C4]
> + ldr r0, [r3, #0x4C4]
> + orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + str r0, [r3, #0x4C4]
> /* Correct strength and disable writes again */
> - bic r6, r6, #SDRAM_PAD_CTRL_DRV_STR_MASK
> - bic r6, r6, #SDRAM_PAD_CTRL_WR_EN
> - orr r6, r6, r1
> - str r6, [r3, #0x4C4]
> + bic r0, r0, #SDRAM_PAD_CTRL_DRV_STR_MASK
> + bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
> + orr r0, r0, r1
> + str r0, [r3, #0x4C4]
> /* Implement Guideline (GL# MEM-4) DQS Reference Delay Tuning */
> /* Relevant for: 88F5181-A1/B0/B1 and 88F5281-A0/B0 */
> /* Get the "sample on reset" register for the DDR frequancy */
> ldr r3, =0x10000
> - ldr r6, [r3, #0x010]
> + ldr r0, [r3, #0x010]
> ldr r1, =MSAR_ARMDDRCLCK_MASK
> - and r1, r6, r1
> + and r1, r0, r1
> - ldr r6, =FTDLL_DDR1_166MHZ
> + ldr r0, =FTDLL_DDR1_166MHZ
> cmp r1, #MSAR_ARMDDRCLCK_333_167
> beq 3f
> cmp r1, #MSAR_ARMDDRCLCK_500_167
> @@ -255,7 +255,7 @@ lowlevel_init:
> cmp r1, #MSAR_ARMDDRCLCK_667_167
> beq 3f
> - ldr r6, =FTDLL_DDR1_200MHZ
> + ldr r0, =FTDLL_DDR1_200MHZ
> cmp r1, #MSAR_ARMDDRCLCK_400_200_1
> beq 3f
> cmp r1, #MSAR_ARMDDRCLCK_400_200
> @@ -265,21 +265,21 @@ lowlevel_init:
> cmp r1, #MSAR_ARMDDRCLCK_800_200
> beq 3f
> - ldr r6, =0
> + ldr r0, =0
> 3:
> /* Use R3 as the base for DRAM registers */
> - add r3, r4, #0x01000
> + add r3, r2, #0x01000
> ldr r2, [r3, #0x484]
> - orr r2, r2, r6
> + orr r2, r2, r0
> str r2, [r3, #0x484]
> /* enable for 2 GB DDR; detection should find out real amount */
> - sub r6, r6, r6
> - str r6, [r3, #0x500]
> - ldr r6, =0x7fff0001
> - str r6, [r3, #0x504]
> + sub r0, r0, r0
> + str r0, [r3, #0x500]
> + ldr r0, =0x7fff0001
> + str r0, [r3, #0x504]
> #endif /* CONFIG_SPL_BUILD */
Looks good to me
Reviewed-by: Chris Packham <judge.packham at gmail.com>
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