[U-Boot] [PATCH V2] arm: armv7: omap3: Fix restore sequence in lowlevel_init

The restore sequence in lowlevel_init was in the wrong order, causing lr to lose its original value and be set equal to ip instead. Also, its use of the stack clashes with that of s_init, so move the s_init call after the restore and turn it into a tail-optimized branch.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net --- V2: move s_init call after restore and tail-optimize it into a branch V1: fix order of restores
arch/arm/cpu/armv7/omap3/lowlevel_init.S | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/arm/cpu/armv7/omap3/lowlevel_init.S b/arch/arm/cpu/armv7/omap3/lowlevel_init.S index ebf69fa..eacfef8 100644 --- a/arch/arm/cpu/armv7/omap3/lowlevel_init.S +++ b/arch/arm/cpu/armv7/omap3/lowlevel_init.S @@ -214,7 +214,7 @@ pll_div_val5:
ENTRY(lowlevel_init) ldr sp, SRAM_STACK - str ip, [sp] /* stash old link register */ + str ip, [sp] /* stash ip register */ mov ip, lr /* save link reg across call */ #if !defined(CONFIG_SYS_NAND_BOOT) && !defined(CONFIG_SYS_ONENAND_BOOT) /* @@ -224,12 +224,11 @@ ENTRY(lowlevel_init) ldr r1, =SRAM_CLK_CODE bl cpy_clk_code #endif /* NAND Boot */ - bl s_init /* go setup pll, mux, memory */ - ldr ip, [sp] /* restore save ip */ mov lr, ip /* restore link reg */ + ldr ip, [sp] /* restore save ip */ + /* tail-call s_init to setup pll, mux, memory */ + b s_init
- /* back to arch calling code */ - mov pc, lr ENDPROC(lowlevel_init)
/* the literal pools origin */

On 10/07/2012 09:24 PM, Albert ARIBAUD wrote:
The restore sequence in lowlevel_init was in the wrong order, causing lr to lose its original value and be set equal to ip instead. Also, its use of the stack clashes with that of s_init, so move the s_init call after the restore and turn it into a tail-optimized branch.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net
V2: move s_init call after restore and tail-optimize it into a branch V1: fix order of restores
arch/arm/cpu/armv7/omap3/lowlevel_init.S | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/arm/cpu/armv7/omap3/lowlevel_init.S b/arch/arm/cpu/armv7/omap3/lowlevel_init.S index ebf69fa..eacfef8 100644 --- a/arch/arm/cpu/armv7/omap3/lowlevel_init.S +++ b/arch/arm/cpu/armv7/omap3/lowlevel_init.S @@ -214,7 +214,7 @@ pll_div_val5:
ENTRY(lowlevel_init) ldr sp, SRAM_STACK
- str ip, [sp] /* stash old link register */
- str ip, [sp] /* stash ip register */ mov ip, lr /* save link reg across call */ #if !defined(CONFIG_SYS_NAND_BOOT) && !defined(CONFIG_SYS_ONENAND_BOOT) /*
@@ -224,12 +224,11 @@ ENTRY(lowlevel_init) ldr r1, =SRAM_CLK_CODE bl cpy_clk_code #endif /* NAND Boot */
- bl s_init /* go setup pll, mux, memory */
- ldr ip, [sp] /* restore save ip */ mov lr, ip /* restore link reg */
- ldr ip, [sp] /* restore save ip */
- /* tail-call s_init to setup pll, mux, memory */
- b s_init
/* back to arch calling code */
mov pc, lr ENDPROC(lowlevel_init)
/* the literal pools origin */
Tested-by: Jeroen Hofstee jeroen@myspectrum.nl
on a tam3517 SOM (am3517 mcu) derived board.
Regards, Jeroen

On Sun, Oct 07, 2012 at 09:24:10AM -0000, Albert ARIBAUD wrote:
The restore sequence in lowlevel_init was in the wrong order, causing lr to lose its original value and be set equal to ip instead. Also, its use of the stack clashes with that of s_init, so move the s_init call after the restore and turn it into a tail-optimized branch.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net Tested-by: Jeroen Hofstee jeroen@myspectrum.nl
Applied to u-boot/master, thanks!
participants (3)
-
Albert ARIBAUD
-
Jeroen Hofstee
-
Tom Rini